v3.26.1
Shareholder Report
 6 Months Ended
Jun. 30, 2026
USD ($)
Holding
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name BlackRock Funds III
Entity Central Index Key 0000893818
Entity Investment Company Type N-1A
Document Period End Date Jun. 30, 2026
C000082487 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2030 Fund
Class Name Class R Shares
Trading Symbol LPRNX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2030 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class R Shares $48(a) 0.94%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 48 [1]
Expense Ratio, Percent 0.94% [1],[2]
Net Assets $ 521,104,474
Holdings Count | Holding 35
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $521,104,474
Number of Portfolio Holdings 35
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 58.2 %
Fixed-Income Funds 36.0 %
Money Market Funds 5.2 %
Other Assets Less Liabilities 0.6
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 32.1 %
BlackRock Diversified Fixed Income Fund, Class K 24.0 %
International Tilts Master Portfolio 10.3 %
iShares 0-5 Year TIPS Bond ETF 8.2 %
iShares Core MSCI Emerging Markets ETF 5.7 %
BlackRock Tactical Opportunities Fund, Class K 5.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.8 %
iShares Global Infrastructure ETF 1.8 %
iShares MSCI EAFE Small-Cap ETF 1.7 %
BlackRock Real Estate Securities Fund 1.3 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 32.1 %
BlackRock Diversified Fixed Income Fund, Class K 24.0 %
International Tilts Master Portfolio 10.3 %
iShares 0-5 Year TIPS Bond ETF 8.2 %
iShares Core MSCI Emerging Markets ETF 5.7 %
BlackRock Tactical Opportunities Fund, Class K 5.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.8 %
iShares Global Infrastructure ETF 1.8 %
iShares MSCI EAFE Small-Cap ETF 1.7 %
BlackRock Real Estate Securities Fund 1.3 %
(b)Excludes short-term securities.
C000051481 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2030 Fund
Class Name Class K Shares
Trading Symbol LPSDX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2030 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class K Shares $12(a) 0.24%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 12 [3]
Expense Ratio, Percent 0.24% [3],[4]
Net Assets $ 521,104,474
Holdings Count | Holding 35
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $521,104,474
Number of Portfolio Holdings 35
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 58.2 %
Fixed-Income Funds 36.0 %
Money Market Funds 5.2 %
Other Assets Less Liabilities 0.6
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 32.1 %
BlackRock Diversified Fixed Income Fund, Class K 24.0 %
International Tilts Master Portfolio 10.3 %
iShares 0-5 Year TIPS Bond ETF 8.2 %
iShares Core MSCI Emerging Markets ETF 5.7 %
BlackRock Tactical Opportunities Fund, Class K 5.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.8 %
iShares Global Infrastructure ETF 1.8 %
iShares MSCI EAFE Small-Cap ETF 1.7 %
BlackRock Real Estate Securities Fund 1.3 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 32.1 %
BlackRock Diversified Fixed Income Fund, Class K 24.0 %
International Tilts Master Portfolio 10.3 %
iShares 0-5 Year TIPS Bond ETF 8.2 %
iShares Core MSCI Emerging Markets ETF 5.7 %
BlackRock Tactical Opportunities Fund, Class K 5.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.8 %
iShares Global Infrastructure ETF 1.8 %
iShares MSCI EAFE Small-Cap ETF 1.7 %
BlackRock Real Estate Securities Fund 1.3 %
(b)Excludes short-term securities.
C000088835 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2030 Fund
Class Name Investor C Shares
Trading Symbol LPCNX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2030 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor C Shares $76(a) 1.49%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 76 [5]
Expense Ratio, Percent 1.49% [5],[6]
Net Assets $ 521,104,474
Holdings Count | Holding 35
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $521,104,474
Number of Portfolio Holdings 35
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 58.2 %
Fixed-Income Funds 36.0 %
Money Market Funds 5.2 %
Other Assets Less Liabilities 0.6
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 32.1 %
BlackRock Diversified Fixed Income Fund, Class K 24.0 %
International Tilts Master Portfolio 10.3 %
iShares 0-5 Year TIPS Bond ETF 8.2 %
iShares Core MSCI Emerging Markets ETF 5.7 %
BlackRock Tactical Opportunities Fund, Class K 5.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.8 %
iShares Global Infrastructure ETF 1.8 %
iShares MSCI EAFE Small-Cap ETF 1.7 %
BlackRock Real Estate Securities Fund 1.3 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 32.1 %
BlackRock Diversified Fixed Income Fund, Class K 24.0 %
International Tilts Master Portfolio 10.3 %
iShares 0-5 Year TIPS Bond ETF 8.2 %
iShares Core MSCI Emerging Markets ETF 5.7 %
BlackRock Tactical Opportunities Fund, Class K 5.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.8 %
iShares Global Infrastructure ETF 1.8 %
iShares MSCI EAFE Small-Cap ETF 1.7 %
BlackRock Real Estate Securities Fund 1.3 %
(b)Excludes short-term securities.
C000011997 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2030 Fund
Class Name Investor A Shares
Trading Symbol LPRDX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2030 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor A Shares $38(a) 0.74%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 38 [7]
Expense Ratio, Percent 0.74% [7],[8]
Net Assets $ 521,104,474
Holdings Count | Holding 35
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $521,104,474
Number of Portfolio Holdings 35
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 58.2 %
Fixed-Income Funds 36.0 %
Money Market Funds 5.2 %
Other Assets Less Liabilities 0.6
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 32.1 %
BlackRock Diversified Fixed Income Fund, Class K 24.0 %
International Tilts Master Portfolio 10.3 %
iShares 0-5 Year TIPS Bond ETF 8.2 %
iShares Core MSCI Emerging Markets ETF 5.7 %
BlackRock Tactical Opportunities Fund, Class K 5.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.8 %
iShares Global Infrastructure ETF 1.8 %
iShares MSCI EAFE Small-Cap ETF 1.7 %
BlackRock Real Estate Securities Fund 1.3 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 32.1 %
BlackRock Diversified Fixed Income Fund, Class K 24.0 %
International Tilts Master Portfolio 10.3 %
iShares 0-5 Year TIPS Bond ETF 8.2 %
iShares Core MSCI Emerging Markets ETF 5.7 %
BlackRock Tactical Opportunities Fund, Class K 5.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.8 %
iShares Global Infrastructure ETF 1.8 %
iShares MSCI EAFE Small-Cap ETF 1.7 %
BlackRock Real Estate Securities Fund 1.3 %
(b)Excludes short-term securities.
C000011998 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2030 Fund
Class Name Institutional Shares
Trading Symbol STLDX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2030 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Institutional Shares $25(a) 0.49%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 25 [9]
Expense Ratio, Percent 0.49% [9],[10]
Net Assets $ 521,104,474
Holdings Count | Holding 35
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $521,104,474
Number of Portfolio Holdings 35
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 58.2 %
Fixed-Income Funds 36.0 %
Money Market Funds 5.2 %
Other Assets Less Liabilities 0.6
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 32.1 %
BlackRock Diversified Fixed Income Fund, Class K 24.0 %
International Tilts Master Portfolio 10.3 %
iShares 0-5 Year TIPS Bond ETF 8.2 %
iShares Core MSCI Emerging Markets ETF 5.7 %
BlackRock Tactical Opportunities Fund, Class K 5.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.8 %
iShares Global Infrastructure ETF 1.8 %
iShares MSCI EAFE Small-Cap ETF 1.7 %
BlackRock Real Estate Securities Fund 1.3 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 32.1 %
BlackRock Diversified Fixed Income Fund, Class K 24.0 %
International Tilts Master Portfolio 10.3 %
iShares 0-5 Year TIPS Bond ETF 8.2 %
iShares Core MSCI Emerging Markets ETF 5.7 %
BlackRock Tactical Opportunities Fund, Class K 5.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.8 %
iShares Global Infrastructure ETF 1.8 %
iShares MSCI EAFE Small-Cap ETF 1.7 %
BlackRock Real Estate Securities Fund 1.3 %
(b)Excludes short-term securities.
C000012000 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2040 Fund
Class Name Institutional Shares
Trading Symbol STLEX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2040 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Institutional Shares $25(a) 0.49%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 25 [11]
Expense Ratio, Percent 0.49% [11],[12]
Net Assets $ 586,243,135
Holdings Count | Holding 34
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $586,243,135
Number of Portfolio Holdings 34
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 74.6 %
Fixed-Income Funds 20.3 %
Money Market Funds 5.1 %
Liabilities in Excess of Other Assets (— )(b)
Ten largest holdings
Security(c) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 38.3 %
BlackRock Diversified Fixed Income Fund, Class K 15.6 %
International Tilts Master Portfolio 15.3 %
iShares Core MSCI Emerging Markets ETF 8.4 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.5 %
BlackRock Real Estate Securities Fund 2.5 %
iShares Global Infrastructure ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares MSCI Canada ETF 0.5 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Rounds to greater than (0.1)%.
​(c)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(c) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 38.3 %
BlackRock Diversified Fixed Income Fund, Class K 15.6 %
International Tilts Master Portfolio 15.3 %
iShares Core MSCI Emerging Markets ETF 8.4 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.5 %
BlackRock Real Estate Securities Fund 2.5 %
iShares Global Infrastructure ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares MSCI Canada ETF 0.5 %
(c)Excludes short-term securities.
C000011999 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2040 Fund
Class Name Investor A Shares
Trading Symbol LPREX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2040 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor A Shares $38(a) 0.74%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 38 [13]
Expense Ratio, Percent 0.74% [13],[14]
Net Assets $ 586,243,135
Holdings Count | Holding 34
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $586,243,135
Number of Portfolio Holdings 34
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 74.6 %
Fixed-Income Funds 20.3 %
Money Market Funds 5.1 %
Liabilities in Excess of Other Assets (— )(b)
Ten largest holdings
Security(c) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 38.3 %
BlackRock Diversified Fixed Income Fund, Class K 15.6 %
International Tilts Master Portfolio 15.3 %
iShares Core MSCI Emerging Markets ETF 8.4 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.5 %
BlackRock Real Estate Securities Fund 2.5 %
iShares Global Infrastructure ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares MSCI Canada ETF 0.5 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Rounds to greater than (0.1)%.
​(c)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(c) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 38.3 %
BlackRock Diversified Fixed Income Fund, Class K 15.6 %
International Tilts Master Portfolio 15.3 %
iShares Core MSCI Emerging Markets ETF 8.4 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.5 %
BlackRock Real Estate Securities Fund 2.5 %
iShares Global Infrastructure ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares MSCI Canada ETF 0.5 %
(c)Excludes short-term securities.
C000088838 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2040 Fund
Class Name Investor C Shares
Trading Symbol LPCKX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2040 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor C Shares $77(a) 1.49%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 77 [15]
Expense Ratio, Percent 1.49% [15],[16]
Net Assets $ 586,243,135
Holdings Count | Holding 34
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $586,243,135
Number of Portfolio Holdings 34
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 74.6 %
Fixed-Income Funds 20.3 %
Money Market Funds 5.1 %
Liabilities in Excess of Other Assets (— )(b)
Ten largest holdings
Security(c) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 38.3 %
BlackRock Diversified Fixed Income Fund, Class K 15.6 %
International Tilts Master Portfolio 15.3 %
iShares Core MSCI Emerging Markets ETF 8.4 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.5 %
BlackRock Real Estate Securities Fund 2.5 %
iShares Global Infrastructure ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares MSCI Canada ETF 0.5 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Rounds to greater than (0.1)%.
​(c)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(c) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 38.3 %
BlackRock Diversified Fixed Income Fund, Class K 15.6 %
International Tilts Master Portfolio 15.3 %
iShares Core MSCI Emerging Markets ETF 8.4 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.5 %
BlackRock Real Estate Securities Fund 2.5 %
iShares Global Infrastructure ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares MSCI Canada ETF 0.5 %
(c)Excludes short-term securities.
C000051482 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2040 Fund
Class Name Class K Shares
Trading Symbol LPSFX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2040 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class K Shares $12(a) 0.24%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 12 [17]
Expense Ratio, Percent 0.24% [17],[18]
Net Assets $ 586,243,135
Holdings Count | Holding 34
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $586,243,135
Number of Portfolio Holdings 34
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 74.6 %
Fixed-Income Funds 20.3 %
Money Market Funds 5.1 %
Liabilities in Excess of Other Assets (— )(b)
Ten largest holdings
Security(c) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 38.3 %
BlackRock Diversified Fixed Income Fund, Class K 15.6 %
International Tilts Master Portfolio 15.3 %
iShares Core MSCI Emerging Markets ETF 8.4 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.5 %
BlackRock Real Estate Securities Fund 2.5 %
iShares Global Infrastructure ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares MSCI Canada ETF 0.5 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Rounds to greater than (0.1)%.
​(c)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(c) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 38.3 %
BlackRock Diversified Fixed Income Fund, Class K 15.6 %
International Tilts Master Portfolio 15.3 %
iShares Core MSCI Emerging Markets ETF 8.4 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.5 %
BlackRock Real Estate Securities Fund 2.5 %
iShares Global Infrastructure ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares MSCI Canada ETF 0.5 %
(c)Excludes short-term securities.
C000082488 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2040 Fund
Class Name Class R Shares
Trading Symbol LPRKX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2040 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class R Shares $49(a) 0.94%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 49 [19]
Expense Ratio, Percent 0.94% [19],[20]
Net Assets $ 586,243,135
Holdings Count | Holding 34
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $586,243,135
Number of Portfolio Holdings 34
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 74.6 %
Fixed-Income Funds 20.3 %
Money Market Funds 5.1 %
Liabilities in Excess of Other Assets (— )(b)
Ten largest holdings
Security(c) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 38.3 %
BlackRock Diversified Fixed Income Fund, Class K 15.6 %
International Tilts Master Portfolio 15.3 %
iShares Core MSCI Emerging Markets ETF 8.4 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.5 %
BlackRock Real Estate Securities Fund 2.5 %
iShares Global Infrastructure ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares MSCI Canada ETF 0.5 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Rounds to greater than (0.1)%.
​(c)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(c) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 38.3 %
BlackRock Diversified Fixed Income Fund, Class K 15.6 %
International Tilts Master Portfolio 15.3 %
iShares Core MSCI Emerging Markets ETF 8.4 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.5 %
BlackRock Real Estate Securities Fund 2.5 %
iShares Global Infrastructure ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares MSCI Canada ETF 0.5 %
(c)Excludes short-term securities.
C000082489 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic Retirement Fund
Class Name Class R Shares
Trading Symbol LPRRX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic Retirement Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class R Shares $47(a) 0.93%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 47 [21]
Expense Ratio, Percent 0.93% [21],[22]
Net Assets $ 480,698,509
Holdings Count | Holding 34
Investment Company Portfolio Turnover 3.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $480,698,509
Number of Portfolio Holdings 34
Portfolio Turnover Rate 3%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Fixed-Income Funds 51.5 %
Equity Funds 45.2 %
Money Market Funds 3.2 %
Other Assets Less Liabilities 0.1
Ten largest holdings
Security(b) Percent of
Net Assets
BlackRock Diversified Fixed Income Fund, Class K 41.6 %
Diversified Equity Alpha Master Portfolio 24.6 %
iShares 0-5 Year TIPS Bond ETF 9.9 %
International Tilts Master Portfolio 7.7 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Core MSCI Emerging Markets ETF 4.2 %
iShares Global Infrastructure ETF 1.7 %
iShares MSCI EAFE Small-Cap ETF 1.3 %
BlackRock Real Estate Securities Fund 0.3 %
iShares Russell 2000 ETF 0.2 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
BlackRock Diversified Fixed Income Fund, Class K 41.6 %
Diversified Equity Alpha Master Portfolio 24.6 %
iShares 0-5 Year TIPS Bond ETF 9.9 %
International Tilts Master Portfolio 7.7 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Core MSCI Emerging Markets ETF 4.2 %
iShares Global Infrastructure ETF 1.7 %
iShares MSCI EAFE Small-Cap ETF 1.3 %
BlackRock Real Estate Securities Fund 0.3 %
iShares Russell 2000 ETF 0.2 %
(b)Excludes short-term securities.
C000051483 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic Retirement Fund
Class Name Class K Shares
Trading Symbol LPSAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic Retirement Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class K Shares $12(a) 0.23%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 12 [23]
Expense Ratio, Percent 0.23% [23],[24]
Net Assets $ 480,698,509
Holdings Count | Holding 34
Investment Company Portfolio Turnover 3.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $480,698,509
Number of Portfolio Holdings 34
Portfolio Turnover Rate 3%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Fixed-Income Funds 51.5 %
Equity Funds 45.2 %
Money Market Funds 3.2 %
Other Assets Less Liabilities 0.1
Ten largest holdings
Security(b) Percent of
Net Assets
BlackRock Diversified Fixed Income Fund, Class K 41.6 %
Diversified Equity Alpha Master Portfolio 24.6 %
iShares 0-5 Year TIPS Bond ETF 9.9 %
International Tilts Master Portfolio 7.7 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Core MSCI Emerging Markets ETF 4.2 %
iShares Global Infrastructure ETF 1.7 %
iShares MSCI EAFE Small-Cap ETF 1.3 %
BlackRock Real Estate Securities Fund 0.3 %
iShares Russell 2000 ETF 0.2 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
BlackRock Diversified Fixed Income Fund, Class K 41.6 %
Diversified Equity Alpha Master Portfolio 24.6 %
iShares 0-5 Year TIPS Bond ETF 9.9 %
International Tilts Master Portfolio 7.7 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Core MSCI Emerging Markets ETF 4.2 %
iShares Global Infrastructure ETF 1.7 %
iShares MSCI EAFE Small-Cap ETF 1.3 %
BlackRock Real Estate Securities Fund 0.3 %
iShares Russell 2000 ETF 0.2 %
(b)Excludes short-term securities.
C000088841 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic Retirement Fund
Class Name Investor C Shares
Trading Symbol LPCRX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic Retirement Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor C Shares $75(a) 1.48%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 75 [25]
Expense Ratio, Percent 1.48% [25],[26]
Net Assets $ 480,698,509
Holdings Count | Holding 34
Investment Company Portfolio Turnover 3.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $480,698,509
Number of Portfolio Holdings 34
Portfolio Turnover Rate 3%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Fixed-Income Funds 51.5 %
Equity Funds 45.2 %
Money Market Funds 3.2 %
Other Assets Less Liabilities 0.1
Ten largest holdings
Security(b) Percent of
Net Assets
BlackRock Diversified Fixed Income Fund, Class K 41.6 %
Diversified Equity Alpha Master Portfolio 24.6 %
iShares 0-5 Year TIPS Bond ETF 9.9 %
International Tilts Master Portfolio 7.7 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Core MSCI Emerging Markets ETF 4.2 %
iShares Global Infrastructure ETF 1.7 %
iShares MSCI EAFE Small-Cap ETF 1.3 %
BlackRock Real Estate Securities Fund 0.3 %
iShares Russell 2000 ETF 0.2 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
BlackRock Diversified Fixed Income Fund, Class K 41.6 %
Diversified Equity Alpha Master Portfolio 24.6 %
iShares 0-5 Year TIPS Bond ETF 9.9 %
International Tilts Master Portfolio 7.7 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Core MSCI Emerging Markets ETF 4.2 %
iShares Global Infrastructure ETF 1.7 %
iShares MSCI EAFE Small-Cap ETF 1.3 %
BlackRock Real Estate Securities Fund 0.3 %
iShares Russell 2000 ETF 0.2 %
(b)Excludes short-term securities.
C000012001 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic Retirement Fund
Class Name Investor A Shares
Trading Symbol LPRAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic Retirement Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor A Shares $37(a) 0.73%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 37 [27]
Expense Ratio, Percent 0.73% [27],[28]
Net Assets $ 480,698,509
Holdings Count | Holding 34
Investment Company Portfolio Turnover 3.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $480,698,509
Number of Portfolio Holdings 34
Portfolio Turnover Rate 3%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Fixed-Income Funds 51.5 %
Equity Funds 45.2 %
Money Market Funds 3.2 %
Other Assets Less Liabilities 0.1
Ten largest holdings
Security(b) Percent of
Net Assets
BlackRock Diversified Fixed Income Fund, Class K 41.6 %
Diversified Equity Alpha Master Portfolio 24.6 %
iShares 0-5 Year TIPS Bond ETF 9.9 %
International Tilts Master Portfolio 7.7 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Core MSCI Emerging Markets ETF 4.2 %
iShares Global Infrastructure ETF 1.7 %
iShares MSCI EAFE Small-Cap ETF 1.3 %
BlackRock Real Estate Securities Fund 0.3 %
iShares Russell 2000 ETF 0.2 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
BlackRock Diversified Fixed Income Fund, Class K 41.6 %
Diversified Equity Alpha Master Portfolio 24.6 %
iShares 0-5 Year TIPS Bond ETF 9.9 %
International Tilts Master Portfolio 7.7 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Core MSCI Emerging Markets ETF 4.2 %
iShares Global Infrastructure ETF 1.7 %
iShares MSCI EAFE Small-Cap ETF 1.3 %
BlackRock Real Estate Securities Fund 0.3 %
iShares Russell 2000 ETF 0.2 %
(b)Excludes short-term securities.
C000012002 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic Retirement Fund
Class Name Institutional Shares
Trading Symbol STLAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic Retirement Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Institutional Shares $24(a) 0.48%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 24 [29]
Expense Ratio, Percent 0.48% [29],[30]
Net Assets $ 480,698,509
Holdings Count | Holding 34
Investment Company Portfolio Turnover 3.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $480,698,509
Number of Portfolio Holdings 34
Portfolio Turnover Rate 3%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Fixed-Income Funds 51.5 %
Equity Funds 45.2 %
Money Market Funds 3.2 %
Other Assets Less Liabilities 0.1
Ten largest holdings
Security(b) Percent of
Net Assets
BlackRock Diversified Fixed Income Fund, Class K 41.6 %
Diversified Equity Alpha Master Portfolio 24.6 %
iShares 0-5 Year TIPS Bond ETF 9.9 %
International Tilts Master Portfolio 7.7 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Core MSCI Emerging Markets ETF 4.2 %
iShares Global Infrastructure ETF 1.7 %
iShares MSCI EAFE Small-Cap ETF 1.3 %
BlackRock Real Estate Securities Fund 0.3 %
iShares Russell 2000 ETF 0.2 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
BlackRock Diversified Fixed Income Fund, Class K 41.6 %
Diversified Equity Alpha Master Portfolio 24.6 %
iShares 0-5 Year TIPS Bond ETF 9.9 %
International Tilts Master Portfolio 7.7 %
BlackRock Tactical Opportunities Fund, Class K 5.1 %
iShares Core MSCI Emerging Markets ETF 4.2 %
iShares Global Infrastructure ETF 1.7 %
iShares MSCI EAFE Small-Cap ETF 1.3 %
BlackRock Real Estate Securities Fund 0.3 %
iShares Russell 2000 ETF 0.2 %
(b)Excludes short-term securities.
C000063261 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2050 Fund
Class Name Institutional Shares
Trading Symbol STLFX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2050 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Institutional Shares $27(a) 0.51%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 27 [31]
Expense Ratio, Percent 0.51% [31],[32]
Net Assets $ 452,126,753
Holdings Count | Holding 31
Investment Company Portfolio Turnover 3.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $452,126,753
Number of Portfolio Holdings 31
Portfolio Turnover Rate 3%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 86.9 %
Money Market Funds 13.3 %
Fixed-Income Funds 6.9 %
Liabilities in Excess of Other Assets (7.1 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.1 %
International Tilts Master Portfolio 14.7 %
iShares Core MSCI Emerging Markets ETF 10.8 %
iShares Core MSCI International Developed Markets ETF 5.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
BlackRock Diversified Fixed Income Fund, Class K 3.5 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.4 %
iShares MSCI EAFE Small-Cap ETF 2.3 %
BlackRock Real Estate Securities Fund 2.1 %
iShares MSCI Canada ETF 0.4 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.1 %
International Tilts Master Portfolio 14.7 %
iShares Core MSCI Emerging Markets ETF 10.8 %
iShares Core MSCI International Developed Markets ETF 5.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
BlackRock Diversified Fixed Income Fund, Class K 3.5 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.4 %
iShares MSCI EAFE Small-Cap ETF 2.3 %
BlackRock Real Estate Securities Fund 2.1 %
iShares MSCI Canada ETF 0.4 %
(b)Excludes short-term securities.
C000063260 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2050 Fund
Class Name Investor A Shares
Trading Symbol LPRFX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2050 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor A Shares $40(a) 0.76%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 40 [33]
Expense Ratio, Percent 0.76% [33],[34]
Net Assets $ 452,126,753
Holdings Count | Holding 31
Investment Company Portfolio Turnover 3.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $452,126,753
Number of Portfolio Holdings 31
Portfolio Turnover Rate 3%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 86.9 %
Money Market Funds 13.3 %
Fixed-Income Funds 6.9 %
Liabilities in Excess of Other Assets (7.1 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.1 %
International Tilts Master Portfolio 14.7 %
iShares Core MSCI Emerging Markets ETF 10.8 %
iShares Core MSCI International Developed Markets ETF 5.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
BlackRock Diversified Fixed Income Fund, Class K 3.5 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.4 %
iShares MSCI EAFE Small-Cap ETF 2.3 %
BlackRock Real Estate Securities Fund 2.1 %
iShares MSCI Canada ETF 0.4 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.1 %
International Tilts Master Portfolio 14.7 %
iShares Core MSCI Emerging Markets ETF 10.8 %
iShares Core MSCI International Developed Markets ETF 5.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
BlackRock Diversified Fixed Income Fund, Class K 3.5 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.4 %
iShares MSCI EAFE Small-Cap ETF 2.3 %
BlackRock Real Estate Securities Fund 2.1 %
iShares MSCI Canada ETF 0.4 %
(b)Excludes short-term securities.
C000088844 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2050 Fund
Class Name Investor C Shares
Trading Symbol LPCPX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2050 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor C Shares $79(a) 1.51%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 79 [35]
Expense Ratio, Percent 1.51% [35],[36]
Net Assets $ 452,126,753
Holdings Count | Holding 31
Investment Company Portfolio Turnover 3.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $452,126,753
Number of Portfolio Holdings 31
Portfolio Turnover Rate 3%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 86.9 %
Money Market Funds 13.3 %
Fixed-Income Funds 6.9 %
Liabilities in Excess of Other Assets (7.1 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.1 %
International Tilts Master Portfolio 14.7 %
iShares Core MSCI Emerging Markets ETF 10.8 %
iShares Core MSCI International Developed Markets ETF 5.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
BlackRock Diversified Fixed Income Fund, Class K 3.5 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.4 %
iShares MSCI EAFE Small-Cap ETF 2.3 %
BlackRock Real Estate Securities Fund 2.1 %
iShares MSCI Canada ETF 0.4 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.1 %
International Tilts Master Portfolio 14.7 %
iShares Core MSCI Emerging Markets ETF 10.8 %
iShares Core MSCI International Developed Markets ETF 5.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
BlackRock Diversified Fixed Income Fund, Class K 3.5 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.4 %
iShares MSCI EAFE Small-Cap ETF 2.3 %
BlackRock Real Estate Securities Fund 2.1 %
iShares MSCI Canada ETF 0.4 %
(b)Excludes short-term securities.
C000063262 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2050 Fund
Class Name Class K Shares
Trading Symbol LPSGX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2050 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class K Shares $14(a) 0.26%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 14 [37]
Expense Ratio, Percent 0.26% [37],[38]
Net Assets $ 452,126,753
Holdings Count | Holding 31
Investment Company Portfolio Turnover 3.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $452,126,753
Number of Portfolio Holdings 31
Portfolio Turnover Rate 3%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 86.9 %
Money Market Funds 13.3 %
Fixed-Income Funds 6.9 %
Liabilities in Excess of Other Assets (7.1 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.1 %
International Tilts Master Portfolio 14.7 %
iShares Core MSCI Emerging Markets ETF 10.8 %
iShares Core MSCI International Developed Markets ETF 5.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
BlackRock Diversified Fixed Income Fund, Class K 3.5 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.4 %
iShares MSCI EAFE Small-Cap ETF 2.3 %
BlackRock Real Estate Securities Fund 2.1 %
iShares MSCI Canada ETF 0.4 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.1 %
International Tilts Master Portfolio 14.7 %
iShares Core MSCI Emerging Markets ETF 10.8 %
iShares Core MSCI International Developed Markets ETF 5.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
BlackRock Diversified Fixed Income Fund, Class K 3.5 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.4 %
iShares MSCI EAFE Small-Cap ETF 2.3 %
BlackRock Real Estate Securities Fund 2.1 %
iShares MSCI Canada ETF 0.4 %
(b)Excludes short-term securities.
C000082490 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2050 Fund
Class Name Class R Shares
Trading Symbol LPRPX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2050 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class R Shares $50(a) 0.96%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 50 [39]
Expense Ratio, Percent 0.96% [39],[40]
Net Assets $ 452,126,753
Holdings Count | Holding 31
Investment Company Portfolio Turnover 3.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $452,126,753
Number of Portfolio Holdings 31
Portfolio Turnover Rate 3%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 86.9 %
Money Market Funds 13.3 %
Fixed-Income Funds 6.9 %
Liabilities in Excess of Other Assets (7.1 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.1 %
International Tilts Master Portfolio 14.7 %
iShares Core MSCI Emerging Markets ETF 10.8 %
iShares Core MSCI International Developed Markets ETF 5.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
BlackRock Diversified Fixed Income Fund, Class K 3.5 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.4 %
iShares MSCI EAFE Small-Cap ETF 2.3 %
BlackRock Real Estate Securities Fund 2.1 %
iShares MSCI Canada ETF 0.4 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.1 %
International Tilts Master Portfolio 14.7 %
iShares Core MSCI Emerging Markets ETF 10.8 %
iShares Core MSCI International Developed Markets ETF 5.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
BlackRock Diversified Fixed Income Fund, Class K 3.5 %
iShares Broad USD Investment Grade Corporate Bond ETF 3.4 %
iShares MSCI EAFE Small-Cap ETF 2.3 %
BlackRock Real Estate Securities Fund 2.1 %
iShares MSCI Canada ETF 0.4 %
(b)Excludes short-term securities.
C000089952 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2035 Fund
Class Name Class R Shares
Trading Symbol LPJRX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2035 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class R Shares $48(a) 0.94%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 48 [41]
Expense Ratio, Percent 0.94% [41],[42]
Net Assets $ 450,794,632
Holdings Count | Holding 35
Investment Company Portfolio Turnover 5.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $450,794,632
Number of Portfolio Holdings 35
Portfolio Turnover Rate 5%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 67.9 %
Fixed-Income Funds 26.5 %
Money Market Funds 5.3 %
Other Assets Less Liabilities 0.3
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 36.7 %
BlackRock Diversified Fixed Income Fund, Class K 21.3 %
International Tilts Master Portfolio 12.9 %
iShares Core MSCI Emerging Markets ETF 7.2 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.6 %
iShares MSCI EAFE Small-Cap ETF 2.1 %
iShares Global Infrastructure ETF 1.8 %
BlackRock Real Estate Securities Fund 1.8 %
iShares 0-5 Year TIPS Bond ETF 0.6 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 36.7 %
BlackRock Diversified Fixed Income Fund, Class K 21.3 %
International Tilts Master Portfolio 12.9 %
iShares Core MSCI Emerging Markets ETF 7.2 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.6 %
iShares MSCI EAFE Small-Cap ETF 2.1 %
iShares Global Infrastructure ETF 1.8 %
BlackRock Real Estate Securities Fund 1.8 %
iShares 0-5 Year TIPS Bond ETF 0.6 %
(b)Excludes short-term securities.
C000089956 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2035 Fund
Class Name Class K Shares
Trading Symbol LPJKX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2035 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class K Shares $12(a) 0.24%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 12 [43]
Expense Ratio, Percent 0.24% [43],[44]
Net Assets $ 450,794,632
Holdings Count | Holding 35
Investment Company Portfolio Turnover 5.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $450,794,632
Number of Portfolio Holdings 35
Portfolio Turnover Rate 5%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 67.9 %
Fixed-Income Funds 26.5 %
Money Market Funds 5.3 %
Other Assets Less Liabilities 0.3
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 36.7 %
BlackRock Diversified Fixed Income Fund, Class K 21.3 %
International Tilts Master Portfolio 12.9 %
iShares Core MSCI Emerging Markets ETF 7.2 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.6 %
iShares MSCI EAFE Small-Cap ETF 2.1 %
iShares Global Infrastructure ETF 1.8 %
BlackRock Real Estate Securities Fund 1.8 %
iShares 0-5 Year TIPS Bond ETF 0.6 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 36.7 %
BlackRock Diversified Fixed Income Fund, Class K 21.3 %
International Tilts Master Portfolio 12.9 %
iShares Core MSCI Emerging Markets ETF 7.2 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.6 %
iShares MSCI EAFE Small-Cap ETF 2.1 %
iShares Global Infrastructure ETF 1.8 %
BlackRock Real Estate Securities Fund 1.8 %
iShares 0-5 Year TIPS Bond ETF 0.6 %
(b)Excludes short-term securities.
C000089954 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2035 Fund
Class Name Investor C Shares
Trading Symbol LPJCX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2035 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor C Shares $77(a) 1.49%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 77 [45]
Expense Ratio, Percent 1.49% [45],[46]
Net Assets $ 450,794,632
Holdings Count | Holding 35
Investment Company Portfolio Turnover 5.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $450,794,632
Number of Portfolio Holdings 35
Portfolio Turnover Rate 5%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 67.9 %
Fixed-Income Funds 26.5 %
Money Market Funds 5.3 %
Other Assets Less Liabilities 0.3
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 36.7 %
BlackRock Diversified Fixed Income Fund, Class K 21.3 %
International Tilts Master Portfolio 12.9 %
iShares Core MSCI Emerging Markets ETF 7.2 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.6 %
iShares MSCI EAFE Small-Cap ETF 2.1 %
iShares Global Infrastructure ETF 1.8 %
BlackRock Real Estate Securities Fund 1.8 %
iShares 0-5 Year TIPS Bond ETF 0.6 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 36.7 %
BlackRock Diversified Fixed Income Fund, Class K 21.3 %
International Tilts Master Portfolio 12.9 %
iShares Core MSCI Emerging Markets ETF 7.2 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.6 %
iShares MSCI EAFE Small-Cap ETF 2.1 %
iShares Global Infrastructure ETF 1.8 %
BlackRock Real Estate Securities Fund 1.8 %
iShares 0-5 Year TIPS Bond ETF 0.6 %
(b)Excludes short-term securities.
C000089953 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2035 Fund
Class Name Investor A Shares
Trading Symbol LPJAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2035 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor A Shares $38(a) 0.74%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 38 [47]
Expense Ratio, Percent 0.74% [47],[48]
Net Assets $ 450,794,632
Holdings Count | Holding 35
Investment Company Portfolio Turnover 5.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $450,794,632
Number of Portfolio Holdings 35
Portfolio Turnover Rate 5%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 67.9 %
Fixed-Income Funds 26.5 %
Money Market Funds 5.3 %
Other Assets Less Liabilities 0.3
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 36.7 %
BlackRock Diversified Fixed Income Fund, Class K 21.3 %
International Tilts Master Portfolio 12.9 %
iShares Core MSCI Emerging Markets ETF 7.2 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.6 %
iShares MSCI EAFE Small-Cap ETF 2.1 %
iShares Global Infrastructure ETF 1.8 %
BlackRock Real Estate Securities Fund 1.8 %
iShares 0-5 Year TIPS Bond ETF 0.6 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 36.7 %
BlackRock Diversified Fixed Income Fund, Class K 21.3 %
International Tilts Master Portfolio 12.9 %
iShares Core MSCI Emerging Markets ETF 7.2 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.6 %
iShares MSCI EAFE Small-Cap ETF 2.1 %
iShares Global Infrastructure ETF 1.8 %
BlackRock Real Estate Securities Fund 1.8 %
iShares 0-5 Year TIPS Bond ETF 0.6 %
(b)Excludes short-term securities.
C000089955 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2035 Fund
Class Name Institutional Shares
Trading Symbol LPJIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2035 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Institutional Shares $25(a) 0.49%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 25 [49]
Expense Ratio, Percent 0.49% [49],[50]
Net Assets $ 450,794,632
Holdings Count | Holding 35
Investment Company Portfolio Turnover 5.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $450,794,632
Number of Portfolio Holdings 35
Portfolio Turnover Rate 5%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 67.9 %
Fixed-Income Funds 26.5 %
Money Market Funds 5.3 %
Other Assets Less Liabilities 0.3
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 36.7 %
BlackRock Diversified Fixed Income Fund, Class K 21.3 %
International Tilts Master Portfolio 12.9 %
iShares Core MSCI Emerging Markets ETF 7.2 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.6 %
iShares MSCI EAFE Small-Cap ETF 2.1 %
iShares Global Infrastructure ETF 1.8 %
BlackRock Real Estate Securities Fund 1.8 %
iShares 0-5 Year TIPS Bond ETF 0.6 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 36.7 %
BlackRock Diversified Fixed Income Fund, Class K 21.3 %
International Tilts Master Portfolio 12.9 %
iShares Core MSCI Emerging Markets ETF 7.2 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.6 %
iShares MSCI EAFE Small-Cap ETF 2.1 %
iShares Global Infrastructure ETF 1.8 %
BlackRock Real Estate Securities Fund 1.8 %
iShares 0-5 Year TIPS Bond ETF 0.6 %
(b)Excludes short-term securities.
C000089959 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2045 Fund
Class Name Institutional Shares
Trading Symbol LPHIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2045 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Institutional Shares $26(a) 0.49%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 26 [51]
Expense Ratio, Percent 0.49% [51],[52]
Net Assets $ 423,375,028
Holdings Count | Holding 33
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $423,375,028
Number of Portfolio Holdings 33
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 80.9 %
Fixed-Income Funds 12.9 %
Money Market Funds 8.8 %
Liabilities in Excess of Other Assets (2.6 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 41.6 %
International Tilts Master Portfolio 14.9 %
iShares Core MSCI Emerging Markets ETF 9.7 %
BlackRock Diversified Fixed Income Fund, Class K 8.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.3 %
BlackRock Real Estate Securities Fund 3.1 %
iShares Core MSCI International Developed Markets ETF 3.0 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares Global Infrastructure ETF 0.9 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 41.6 %
International Tilts Master Portfolio 14.9 %
iShares Core MSCI Emerging Markets ETF 9.7 %
BlackRock Diversified Fixed Income Fund, Class K 8.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.3 %
BlackRock Real Estate Securities Fund 3.1 %
iShares Core MSCI International Developed Markets ETF 3.0 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares Global Infrastructure ETF 0.9 %
(b)Excludes short-term securities.
C000089957 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2045 Fund
Class Name Investor A Shares
Trading Symbol LPHAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2045 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor A Shares $39(a) 0.74%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 39 [53]
Expense Ratio, Percent 0.74% [53],[54]
Net Assets $ 423,375,028
Holdings Count | Holding 33
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $423,375,028
Number of Portfolio Holdings 33
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 80.9 %
Fixed-Income Funds 12.9 %
Money Market Funds 8.8 %
Liabilities in Excess of Other Assets (2.6 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 41.6 %
International Tilts Master Portfolio 14.9 %
iShares Core MSCI Emerging Markets ETF 9.7 %
BlackRock Diversified Fixed Income Fund, Class K 8.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.3 %
BlackRock Real Estate Securities Fund 3.1 %
iShares Core MSCI International Developed Markets ETF 3.0 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares Global Infrastructure ETF 0.9 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 41.6 %
International Tilts Master Portfolio 14.9 %
iShares Core MSCI Emerging Markets ETF 9.7 %
BlackRock Diversified Fixed Income Fund, Class K 8.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.3 %
BlackRock Real Estate Securities Fund 3.1 %
iShares Core MSCI International Developed Markets ETF 3.0 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares Global Infrastructure ETF 0.9 %
(b)Excludes short-term securities.
C000089958 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2045 Fund
Class Name Investor C Shares
Trading Symbol LPHCX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2045 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor C Shares $78(a) 1.50%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 78 [55]
Expense Ratio, Percent 1.50% [55],[56]
Net Assets $ 423,375,028
Holdings Count | Holding 33
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $423,375,028
Number of Portfolio Holdings 33
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 80.9 %
Fixed-Income Funds 12.9 %
Money Market Funds 8.8 %
Liabilities in Excess of Other Assets (2.6 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 41.6 %
International Tilts Master Portfolio 14.9 %
iShares Core MSCI Emerging Markets ETF 9.7 %
BlackRock Diversified Fixed Income Fund, Class K 8.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.3 %
BlackRock Real Estate Securities Fund 3.1 %
iShares Core MSCI International Developed Markets ETF 3.0 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares Global Infrastructure ETF 0.9 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 41.6 %
International Tilts Master Portfolio 14.9 %
iShares Core MSCI Emerging Markets ETF 9.7 %
BlackRock Diversified Fixed Income Fund, Class K 8.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.3 %
BlackRock Real Estate Securities Fund 3.1 %
iShares Core MSCI International Developed Markets ETF 3.0 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares Global Infrastructure ETF 0.9 %
(b)Excludes short-term securities.
C000089960 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2045 Fund
Class Name Class K Shares
Trading Symbol LPHKX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2045 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class K Shares $13(a) 0.24%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 13 [57]
Expense Ratio, Percent 0.24% [57],[58]
Net Assets $ 423,375,028
Holdings Count | Holding 33
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $423,375,028
Number of Portfolio Holdings 33
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 80.9 %
Fixed-Income Funds 12.9 %
Money Market Funds 8.8 %
Liabilities in Excess of Other Assets (2.6 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 41.6 %
International Tilts Master Portfolio 14.9 %
iShares Core MSCI Emerging Markets ETF 9.7 %
BlackRock Diversified Fixed Income Fund, Class K 8.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.3 %
BlackRock Real Estate Securities Fund 3.1 %
iShares Core MSCI International Developed Markets ETF 3.0 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares Global Infrastructure ETF 0.9 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 41.6 %
International Tilts Master Portfolio 14.9 %
iShares Core MSCI Emerging Markets ETF 9.7 %
BlackRock Diversified Fixed Income Fund, Class K 8.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.3 %
BlackRock Real Estate Securities Fund 3.1 %
iShares Core MSCI International Developed Markets ETF 3.0 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares Global Infrastructure ETF 0.9 %
(b)Excludes short-term securities.
C000089961 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2045 Fund
Class Name Class R Shares
Trading Symbol LPHRX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2045 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class R Shares $49(a) 0.94%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 49 [59]
Expense Ratio, Percent 0.94% [59],[60]
Net Assets $ 423,375,028
Holdings Count | Holding 33
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $423,375,028
Number of Portfolio Holdings 33
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 80.9 %
Fixed-Income Funds 12.9 %
Money Market Funds 8.8 %
Liabilities in Excess of Other Assets (2.6 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 41.6 %
International Tilts Master Portfolio 14.9 %
iShares Core MSCI Emerging Markets ETF 9.7 %
BlackRock Diversified Fixed Income Fund, Class K 8.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.3 %
BlackRock Real Estate Securities Fund 3.1 %
iShares Core MSCI International Developed Markets ETF 3.0 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares Global Infrastructure ETF 0.9 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 41.6 %
International Tilts Master Portfolio 14.9 %
iShares Core MSCI Emerging Markets ETF 9.7 %
BlackRock Diversified Fixed Income Fund, Class K 8.6 %
BlackRock Tactical Opportunities Fund, Class K 4.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 4.3 %
BlackRock Real Estate Securities Fund 3.1 %
iShares Core MSCI International Developed Markets ETF 3.0 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
iShares Global Infrastructure ETF 0.9 %
(b)Excludes short-term securities.
C000089966 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2055 Fund
Class Name Class R Shares
Trading Symbol LPVRX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2055 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class R Shares $51(a) 0.97%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 51 [61]
Expense Ratio, Percent 0.97% [61],[62]
Net Assets $ 353,713,724
Holdings Count | Holding 33
Investment Company Portfolio Turnover 7.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $353,713,724
Number of Portfolio Holdings 33
Portfolio Turnover Rate 7%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 92.7 %
Money Market Funds 12.5 %
Fixed-Income Funds 3.9 %
Liabilities in Excess of Other Assets (9.1 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.6 %
International Tilts Master Portfolio 15.0 %
iShares Core MSCI Emerging Markets ETF 11.1 %
iShares Core MSCI International Developed Markets ETF 6.7 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares Broad USD Investment Grade Corporate Bond ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
BlackRock Diversified Fixed Income Fund, Class K 1.6 %
iShares Russell 2000 ETF 0.9 %
BlackRock Real Estate Securities Fund 0.8 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.6 %
International Tilts Master Portfolio 15.0 %
iShares Core MSCI Emerging Markets ETF 11.1 %
iShares Core MSCI International Developed Markets ETF 6.7 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares Broad USD Investment Grade Corporate Bond ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
BlackRock Diversified Fixed Income Fund, Class K 1.6 %
iShares Russell 2000 ETF 0.9 %
BlackRock Real Estate Securities Fund 0.8 %
(b)Excludes short-term securities.
C000089965 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2055 Fund
Class Name Class K Shares
Trading Symbol LPVKX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2055 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class K Shares $14(a) 0.27%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 14 [63]
Expense Ratio, Percent 0.27% [63],[64]
Net Assets $ 353,713,724
Holdings Count | Holding 33
Investment Company Portfolio Turnover 7.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $353,713,724
Number of Portfolio Holdings 33
Portfolio Turnover Rate 7%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 92.7 %
Money Market Funds 12.5 %
Fixed-Income Funds 3.9 %
Liabilities in Excess of Other Assets (9.1 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.6 %
International Tilts Master Portfolio 15.0 %
iShares Core MSCI Emerging Markets ETF 11.1 %
iShares Core MSCI International Developed Markets ETF 6.7 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares Broad USD Investment Grade Corporate Bond ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
BlackRock Diversified Fixed Income Fund, Class K 1.6 %
iShares Russell 2000 ETF 0.9 %
BlackRock Real Estate Securities Fund 0.8 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.6 %
International Tilts Master Portfolio 15.0 %
iShares Core MSCI Emerging Markets ETF 11.1 %
iShares Core MSCI International Developed Markets ETF 6.7 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares Broad USD Investment Grade Corporate Bond ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
BlackRock Diversified Fixed Income Fund, Class K 1.6 %
iShares Russell 2000 ETF 0.9 %
BlackRock Real Estate Securities Fund 0.8 %
(b)Excludes short-term securities.
C000089963 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2055 Fund
Class Name Investor C Shares
Trading Symbol LPVCX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2055 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor C Shares $80(a) 1.52%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 80 [65]
Expense Ratio, Percent 1.52% [65],[66]
Net Assets $ 353,713,724
Holdings Count | Holding 33
Investment Company Portfolio Turnover 7.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $353,713,724
Number of Portfolio Holdings 33
Portfolio Turnover Rate 7%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 92.7 %
Money Market Funds 12.5 %
Fixed-Income Funds 3.9 %
Liabilities in Excess of Other Assets (9.1 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.6 %
International Tilts Master Portfolio 15.0 %
iShares Core MSCI Emerging Markets ETF 11.1 %
iShares Core MSCI International Developed Markets ETF 6.7 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares Broad USD Investment Grade Corporate Bond ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
BlackRock Diversified Fixed Income Fund, Class K 1.6 %
iShares Russell 2000 ETF 0.9 %
BlackRock Real Estate Securities Fund 0.8 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.6 %
International Tilts Master Portfolio 15.0 %
iShares Core MSCI Emerging Markets ETF 11.1 %
iShares Core MSCI International Developed Markets ETF 6.7 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares Broad USD Investment Grade Corporate Bond ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
BlackRock Diversified Fixed Income Fund, Class K 1.6 %
iShares Russell 2000 ETF 0.9 %
BlackRock Real Estate Securities Fund 0.8 %
(b)Excludes short-term securities.
C000089962 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2055 Fund
Class Name Investor A Shares
Trading Symbol LPVAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2055 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor A Shares $41(a) 0.77%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 41 [67]
Expense Ratio, Percent 0.77% [67],[68]
Net Assets $ 353,713,724
Holdings Count | Holding 33
Investment Company Portfolio Turnover 7.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $353,713,724
Number of Portfolio Holdings 33
Portfolio Turnover Rate 7%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 92.7 %
Money Market Funds 12.5 %
Fixed-Income Funds 3.9 %
Liabilities in Excess of Other Assets (9.1 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.6 %
International Tilts Master Portfolio 15.0 %
iShares Core MSCI Emerging Markets ETF 11.1 %
iShares Core MSCI International Developed Markets ETF 6.7 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares Broad USD Investment Grade Corporate Bond ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
BlackRock Diversified Fixed Income Fund, Class K 1.6 %
iShares Russell 2000 ETF 0.9 %
BlackRock Real Estate Securities Fund 0.8 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.6 %
International Tilts Master Portfolio 15.0 %
iShares Core MSCI Emerging Markets ETF 11.1 %
iShares Core MSCI International Developed Markets ETF 6.7 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares Broad USD Investment Grade Corporate Bond ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
BlackRock Diversified Fixed Income Fund, Class K 1.6 %
iShares Russell 2000 ETF 0.9 %
BlackRock Real Estate Securities Fund 0.8 %
(b)Excludes short-term securities.
C000089964 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2055 Fund
Class Name Institutional Shares
Trading Symbol LPVIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2055 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Institutional Shares $27(a) 0.52%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 27 [69]
Expense Ratio, Percent 0.52% [69],[70]
Net Assets $ 353,713,724
Holdings Count | Holding 33
Investment Company Portfolio Turnover 7.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $353,713,724
Number of Portfolio Holdings 33
Portfolio Turnover Rate 7%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 92.7 %
Money Market Funds 12.5 %
Fixed-Income Funds 3.9 %
Liabilities in Excess of Other Assets (9.1 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.6 %
International Tilts Master Portfolio 15.0 %
iShares Core MSCI Emerging Markets ETF 11.1 %
iShares Core MSCI International Developed Markets ETF 6.7 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares Broad USD Investment Grade Corporate Bond ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
BlackRock Diversified Fixed Income Fund, Class K 1.6 %
iShares Russell 2000 ETF 0.9 %
BlackRock Real Estate Securities Fund 0.8 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.6 %
International Tilts Master Portfolio 15.0 %
iShares Core MSCI Emerging Markets ETF 11.1 %
iShares Core MSCI International Developed Markets ETF 6.7 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares Broad USD Investment Grade Corporate Bond ETF 2.3 %
iShares MSCI EAFE Small-Cap ETF 2.2 %
BlackRock Diversified Fixed Income Fund, Class K 1.6 %
iShares Russell 2000 ETF 0.9 %
BlackRock Real Estate Securities Fund 0.8 %
(b)Excludes short-term securities.
C000187070 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2060 Fund
Class Name Institutional Shares
Trading Symbol LPDIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2060 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Institutional Shares $27(a) 0.52%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 27 [71]
Expense Ratio, Percent 0.52% [71],[72]
Net Assets $ 186,481,801
Holdings Count | Holding 31
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $186,481,801
Number of Portfolio Holdings 31
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 94.1 %
Money Market Funds 14.1 %
Fixed-Income Funds 1.6 %
Liabilities in Excess of Other Assets (9.8 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 15.1 %
iShares Core MSCI Emerging Markets ETF 10.9 %
iShares Core MSCI International Developed Markets ETF 7.1 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 2.0 %
iShares Russell 2000 ETF 1.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.8 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 15.1 %
iShares Core MSCI Emerging Markets ETF 10.9 %
iShares Core MSCI International Developed Markets ETF 7.1 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 2.0 %
iShares Russell 2000 ETF 1.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.8 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
(b)Excludes short-term securities.
C000187068 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2060 Fund
Class Name Investor A Shares
Trading Symbol LPDAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2060 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor A Shares $41(a) 0.77%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 41 [73]
Expense Ratio, Percent 0.77% [73],[74]
Net Assets $ 186,481,801
Holdings Count | Holding 31
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $186,481,801
Number of Portfolio Holdings 31
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 94.1 %
Money Market Funds 14.1 %
Fixed-Income Funds 1.6 %
Liabilities in Excess of Other Assets (9.8 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 15.1 %
iShares Core MSCI Emerging Markets ETF 10.9 %
iShares Core MSCI International Developed Markets ETF 7.1 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 2.0 %
iShares Russell 2000 ETF 1.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.8 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 15.1 %
iShares Core MSCI Emerging Markets ETF 10.9 %
iShares Core MSCI International Developed Markets ETF 7.1 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 2.0 %
iShares Russell 2000 ETF 1.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.8 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
(b)Excludes short-term securities.
C000187069 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2060 Fund
Class Name Investor C Shares
Trading Symbol LPDCX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2060 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor C Shares $80(a) 1.52%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 80 [75]
Expense Ratio, Percent 1.52% [75],[76]
Net Assets $ 186,481,801
Holdings Count | Holding 31
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $186,481,801
Number of Portfolio Holdings 31
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 94.1 %
Money Market Funds 14.1 %
Fixed-Income Funds 1.6 %
Liabilities in Excess of Other Assets (9.8 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 15.1 %
iShares Core MSCI Emerging Markets ETF 10.9 %
iShares Core MSCI International Developed Markets ETF 7.1 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 2.0 %
iShares Russell 2000 ETF 1.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.8 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 15.1 %
iShares Core MSCI Emerging Markets ETF 10.9 %
iShares Core MSCI International Developed Markets ETF 7.1 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 2.0 %
iShares Russell 2000 ETF 1.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.8 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
(b)Excludes short-term securities.
C000187072 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2060 Fund
Class Name Class K Shares
Trading Symbol LPDKX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2060 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class K Shares $14(a) 0.27%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 14 [77]
Expense Ratio, Percent 0.27% [77],[78]
Net Assets $ 186,481,801
Holdings Count | Holding 31
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $186,481,801
Number of Portfolio Holdings 31
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 94.1 %
Money Market Funds 14.1 %
Fixed-Income Funds 1.6 %
Liabilities in Excess of Other Assets (9.8 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 15.1 %
iShares Core MSCI Emerging Markets ETF 10.9 %
iShares Core MSCI International Developed Markets ETF 7.1 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 2.0 %
iShares Russell 2000 ETF 1.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.8 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 15.1 %
iShares Core MSCI Emerging Markets ETF 10.9 %
iShares Core MSCI International Developed Markets ETF 7.1 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 2.0 %
iShares Russell 2000 ETF 1.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.8 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
(b)Excludes short-term securities.
C000187071 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2060 Fund
Class Name Class R Shares
Trading Symbol LPDRX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2060 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class R Shares $51(a) 0.97%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 51 [79]
Expense Ratio, Percent 0.97% [79],[80]
Net Assets $ 186,481,801
Holdings Count | Holding 31
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $186,481,801
Number of Portfolio Holdings 31
Portfolio Turnover Rate 4%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 94.1 %
Money Market Funds 14.1 %
Fixed-Income Funds 1.6 %
Liabilities in Excess of Other Assets (9.8 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 15.1 %
iShares Core MSCI Emerging Markets ETF 10.9 %
iShares Core MSCI International Developed Markets ETF 7.1 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 2.0 %
iShares Russell 2000 ETF 1.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.8 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 15.1 %
iShares Core MSCI Emerging Markets ETF 10.9 %
iShares Core MSCI International Developed Markets ETF 7.1 %
BlackRock Tactical Opportunities Fund, Class K 4.8 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 2.0 %
iShares Russell 2000 ETF 1.0 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.8 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
(b)Excludes short-term securities.
C000213847 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2065 Fund
Class Name Class R Shares
Trading Symbol LPWRX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2065 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class R Shares $51(a) 0.97%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 51 [81]
Expense Ratio, Percent 0.97% [81],[82]
Net Assets $ 104,886,336
Holdings Count | Holding 31
Investment Company Portfolio Turnover 1.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $104,886,336
Number of Portfolio Holdings 31
Portfolio Turnover Rate 1%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 93.0 %
Money Market Funds 16.2 %
Fixed-Income Funds 1.6 %
Liabilities in Excess of Other Assets (10.8 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 14.8 %
iShares Core MSCI Emerging Markets ETF 10.7 %
iShares Core MSCI International Developed Markets ETF 6.8 %
BlackRock Tactical Opportunities Fund, Class K 4.7 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 1.9 %
iShares Russell 2000 ETF 0.9 %
BlackRock Diversified Fixed Income Fund, Class K 0.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.7 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 14.8 %
iShares Core MSCI Emerging Markets ETF 10.7 %
iShares Core MSCI International Developed Markets ETF 6.8 %
BlackRock Tactical Opportunities Fund, Class K 4.7 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 1.9 %
iShares Russell 2000 ETF 0.9 %
BlackRock Diversified Fixed Income Fund, Class K 0.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.7 %
(b)Excludes short-term securities.
C000213844 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2065 Fund
Class Name Class K Shares
Trading Symbol LPWKX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2065 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class K Shares $14(a) 0.27%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 14 [83]
Expense Ratio, Percent 0.27% [83],[84]
Net Assets $ 104,886,336
Holdings Count | Holding 31
Investment Company Portfolio Turnover 1.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $104,886,336
Number of Portfolio Holdings 31
Portfolio Turnover Rate 1%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 93.0 %
Money Market Funds 16.2 %
Fixed-Income Funds 1.6 %
Liabilities in Excess of Other Assets (10.8 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 14.8 %
iShares Core MSCI Emerging Markets ETF 10.7 %
iShares Core MSCI International Developed Markets ETF 6.8 %
BlackRock Tactical Opportunities Fund, Class K 4.7 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 1.9 %
iShares Russell 2000 ETF 0.9 %
BlackRock Diversified Fixed Income Fund, Class K 0.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.7 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 14.8 %
iShares Core MSCI Emerging Markets ETF 10.7 %
iShares Core MSCI International Developed Markets ETF 6.8 %
BlackRock Tactical Opportunities Fund, Class K 4.7 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 1.9 %
iShares Russell 2000 ETF 0.9 %
BlackRock Diversified Fixed Income Fund, Class K 0.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.7 %
(b)Excludes short-term securities.
C000213843 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2065 Fund
Class Name Investor C Shares
Trading Symbol LPWCX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2065 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor C Shares $80(a) 1.52%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 80 [85]
Expense Ratio, Percent 1.52% [85],[86]
Net Assets $ 104,886,336
Holdings Count | Holding 31
Investment Company Portfolio Turnover 1.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $104,886,336
Number of Portfolio Holdings 31
Portfolio Turnover Rate 1%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 93.0 %
Money Market Funds 16.2 %
Fixed-Income Funds 1.6 %
Liabilities in Excess of Other Assets (10.8 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 14.8 %
iShares Core MSCI Emerging Markets ETF 10.7 %
iShares Core MSCI International Developed Markets ETF 6.8 %
BlackRock Tactical Opportunities Fund, Class K 4.7 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 1.9 %
iShares Russell 2000 ETF 0.9 %
BlackRock Diversified Fixed Income Fund, Class K 0.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.7 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 14.8 %
iShares Core MSCI Emerging Markets ETF 10.7 %
iShares Core MSCI International Developed Markets ETF 6.8 %
BlackRock Tactical Opportunities Fund, Class K 4.7 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 1.9 %
iShares Russell 2000 ETF 0.9 %
BlackRock Diversified Fixed Income Fund, Class K 0.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.7 %
(b)Excludes short-term securities.
C000213845 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2065 Fund
Class Name Investor A Shares
Trading Symbol LPWAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2065 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor A Shares $41(a) 0.77%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 41 [87]
Expense Ratio, Percent 0.77% [87],[88]
Net Assets $ 104,886,336
Holdings Count | Holding 31
Investment Company Portfolio Turnover 1.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $104,886,336
Number of Portfolio Holdings 31
Portfolio Turnover Rate 1%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 93.0 %
Money Market Funds 16.2 %
Fixed-Income Funds 1.6 %
Liabilities in Excess of Other Assets (10.8 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 14.8 %
iShares Core MSCI Emerging Markets ETF 10.7 %
iShares Core MSCI International Developed Markets ETF 6.8 %
BlackRock Tactical Opportunities Fund, Class K 4.7 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 1.9 %
iShares Russell 2000 ETF 0.9 %
BlackRock Diversified Fixed Income Fund, Class K 0.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.7 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 14.8 %
iShares Core MSCI Emerging Markets ETF 10.7 %
iShares Core MSCI International Developed Markets ETF 6.8 %
BlackRock Tactical Opportunities Fund, Class K 4.7 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 1.9 %
iShares Russell 2000 ETF 0.9 %
BlackRock Diversified Fixed Income Fund, Class K 0.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.7 %
(b)Excludes short-term securities.
C000213846 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2065 Fund
Class Name Institutional Shares
Trading Symbol LPWIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2065 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Institutional Shares $27(a) 0.52%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 27 [89]
Expense Ratio, Percent 0.52% [89],[90]
Net Assets $ 104,886,336
Holdings Count | Holding 31
Investment Company Portfolio Turnover 1.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $104,886,336
Number of Portfolio Holdings 31
Portfolio Turnover Rate 1%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 93.0 %
Money Market Funds 16.2 %
Fixed-Income Funds 1.6 %
Liabilities in Excess of Other Assets (10.8 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 14.8 %
iShares Core MSCI Emerging Markets ETF 10.7 %
iShares Core MSCI International Developed Markets ETF 6.8 %
BlackRock Tactical Opportunities Fund, Class K 4.7 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 1.9 %
iShares Russell 2000 ETF 0.9 %
BlackRock Diversified Fixed Income Fund, Class K 0.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.7 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 50.5 %
International Tilts Master Portfolio 14.8 %
iShares Core MSCI Emerging Markets ETF 10.7 %
iShares Core MSCI International Developed Markets ETF 6.8 %
BlackRock Tactical Opportunities Fund, Class K 4.7 %
iShares MSCI Canada ETF 2.2 %
iShares MSCI EAFE Small-Cap ETF 1.9 %
iShares Russell 2000 ETF 0.9 %
BlackRock Diversified Fixed Income Fund, Class K 0.9 %
iShares Broad USD Investment Grade Corporate Bond ETF 0.7 %
(b)Excludes short-term securities.
C000251825 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2070 Fund
Class Name Institutional Shares
Trading Symbol LPYIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2070 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Institutional Shares $27(a) 0.51%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 27 [91]
Expense Ratio, Percent 0.51% [91],[92]
Net Assets $ 8,053,094
Holdings Count | Holding 28
Investment Company Portfolio Turnover 12.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $8,053,094
Number of Portfolio Holdings 28
Portfolio Turnover Rate 12%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 91.3 %
Money Market Funds 13.2 %
Fixed-Income Funds 1.3 %
Liabilities in Excess of Other Assets (5.8 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.4 %
International Tilts Master Portfolio 13.9 %
iShares Core MSCI Emerging Markets ETF 12.5 %
iShares Core MSCI International Developed Markets ETF 6.5 %
BlackRock Tactical Opportunities Fund, Class K 4.5 %
iShares MSCI Canada ETF 2.3 %
iShares Core MSCI EAFE ETF 1.9 %
iShares Russell 2000 ETF 1.5 %
iShares MSCI EAFE Small-Cap ETF 1.0 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.4 %
International Tilts Master Portfolio 13.9 %
iShares Core MSCI Emerging Markets ETF 12.5 %
iShares Core MSCI International Developed Markets ETF 6.5 %
BlackRock Tactical Opportunities Fund, Class K 4.5 %
iShares MSCI Canada ETF 2.3 %
iShares Core MSCI EAFE ETF 1.9 %
iShares Russell 2000 ETF 1.5 %
iShares MSCI EAFE Small-Cap ETF 1.0 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
(b)Excludes short-term securities.
C000251826 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2070 Fund
Class Name Investor A Shares
Trading Symbol LPYAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2070 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor A Shares $40(a) 0.76%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 40 [93]
Expense Ratio, Percent 0.76% [93],[94]
Net Assets $ 8,053,094
Holdings Count | Holding 28
Investment Company Portfolio Turnover 12.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $8,053,094
Number of Portfolio Holdings 28
Portfolio Turnover Rate 12%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 91.3 %
Money Market Funds 13.2 %
Fixed-Income Funds 1.3 %
Liabilities in Excess of Other Assets (5.8 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.4 %
International Tilts Master Portfolio 13.9 %
iShares Core MSCI Emerging Markets ETF 12.5 %
iShares Core MSCI International Developed Markets ETF 6.5 %
BlackRock Tactical Opportunities Fund, Class K 4.5 %
iShares MSCI Canada ETF 2.3 %
iShares Core MSCI EAFE ETF 1.9 %
iShares Russell 2000 ETF 1.5 %
iShares MSCI EAFE Small-Cap ETF 1.0 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.4 %
International Tilts Master Portfolio 13.9 %
iShares Core MSCI Emerging Markets ETF 12.5 %
iShares Core MSCI International Developed Markets ETF 6.5 %
BlackRock Tactical Opportunities Fund, Class K 4.5 %
iShares MSCI Canada ETF 2.3 %
iShares Core MSCI EAFE ETF 1.9 %
iShares Russell 2000 ETF 1.5 %
iShares MSCI EAFE Small-Cap ETF 1.0 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
(b)Excludes short-term securities.
C000251827 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2070 Fund
Class Name Investor C Shares
Trading Symbol LPYCX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2070 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Investor C Shares $80(a) 1.52%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 80 [95]
Expense Ratio, Percent 1.52% [95],[96]
Net Assets $ 8,053,094
Holdings Count | Holding 28
Investment Company Portfolio Turnover 12.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $8,053,094
Number of Portfolio Holdings 28
Portfolio Turnover Rate 12%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 91.3 %
Money Market Funds 13.2 %
Fixed-Income Funds 1.3 %
Liabilities in Excess of Other Assets (5.8 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.4 %
International Tilts Master Portfolio 13.9 %
iShares Core MSCI Emerging Markets ETF 12.5 %
iShares Core MSCI International Developed Markets ETF 6.5 %
BlackRock Tactical Opportunities Fund, Class K 4.5 %
iShares MSCI Canada ETF 2.3 %
iShares Core MSCI EAFE ETF 1.9 %
iShares Russell 2000 ETF 1.5 %
iShares MSCI EAFE Small-Cap ETF 1.0 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.4 %
International Tilts Master Portfolio 13.9 %
iShares Core MSCI Emerging Markets ETF 12.5 %
iShares Core MSCI International Developed Markets ETF 6.5 %
BlackRock Tactical Opportunities Fund, Class K 4.5 %
iShares MSCI Canada ETF 2.3 %
iShares Core MSCI EAFE ETF 1.9 %
iShares Russell 2000 ETF 1.5 %
iShares MSCI EAFE Small-Cap ETF 1.0 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
(b)Excludes short-term securities.
C000251828 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2070 Fund
Class Name Class K Shares
Trading Symbol LPYKX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2070 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class K Shares $14(a) 0.26%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 14 [97]
Expense Ratio, Percent 0.26% [97],[98]
Net Assets $ 8,053,094
Holdings Count | Holding 28
Investment Company Portfolio Turnover 12.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $8,053,094
Number of Portfolio Holdings 28
Portfolio Turnover Rate 12%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 91.3 %
Money Market Funds 13.2 %
Fixed-Income Funds 1.3 %
Liabilities in Excess of Other Assets (5.8 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.4 %
International Tilts Master Portfolio 13.9 %
iShares Core MSCI Emerging Markets ETF 12.5 %
iShares Core MSCI International Developed Markets ETF 6.5 %
BlackRock Tactical Opportunities Fund, Class K 4.5 %
iShares MSCI Canada ETF 2.3 %
iShares Core MSCI EAFE ETF 1.9 %
iShares Russell 2000 ETF 1.5 %
iShares MSCI EAFE Small-Cap ETF 1.0 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.4 %
International Tilts Master Portfolio 13.9 %
iShares Core MSCI Emerging Markets ETF 12.5 %
iShares Core MSCI International Developed Markets ETF 6.5 %
BlackRock Tactical Opportunities Fund, Class K 4.5 %
iShares MSCI Canada ETF 2.3 %
iShares Core MSCI EAFE ETF 1.9 %
iShares Russell 2000 ETF 1.5 %
iShares MSCI EAFE Small-Cap ETF 1.0 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
(b)Excludes short-term securities.
C000251824 [Member]  
Shareholder Report [Line Items]  
Fund Name BlackRock LifePath® Dynamic 2070 Fund
Class Name Class R Shares
Trading Symbol LPYRX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BlackRock LifePath® Dynamic 2070 Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441‑7762.
Additional Information Phone Number (800) 441‑7762
Additional Information Website blackrock.com/fundreports
Expenses [Text Block]
What were the Fund costs for the last six months ?
(based on a hypothetical $10,000 investment)
Class name Costs of a $10,000
investment		 Costs paid as a percentage of a
$10,000 investment
Class R Shares $51(a) 0.96%(a)(b)
​(a)
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
​(b)
Annualized.
Expenses Paid, Amount $ 51 [99]
Expense Ratio, Percent 0.96% [99],[100]
Net Assets $ 8,053,094
Holdings Count | Holding 28
Investment Company Portfolio Turnover 12.00%
Additional Fund Statistics [Text Block]
Key Fund statistics
Net Assets $8,053,094
Number of Portfolio Holdings 28
Portfolio Turnover Rate 12%
Holdings [Text Block]
What did the Fund invest in?
(as of June 30, 2026)
Portfolio composition
Asset Type(a) Percent of
Net Assets
Equity Funds 91.3 %
Money Market Funds 13.2 %
Fixed-Income Funds 1.3 %
Liabilities in Excess of Other Assets (5.8 )
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.4 %
International Tilts Master Portfolio 13.9 %
iShares Core MSCI Emerging Markets ETF 12.5 %
iShares Core MSCI International Developed Markets ETF 6.5 %
BlackRock Tactical Opportunities Fund, Class K 4.5 %
iShares MSCI Canada ETF 2.3 %
iShares Core MSCI EAFE ETF 1.9 %
iShares Russell 2000 ETF 1.5 %
iShares MSCI EAFE Small-Cap ETF 1.0 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
​(a)
The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
​(b)
Excludes short-term securities.
Largest Holdings [Text Block]
Ten largest holdings
Security(b) Percent of
Net Assets
Diversified Equity Alpha Master Portfolio 46.4 %
International Tilts Master Portfolio 13.9 %
iShares Core MSCI Emerging Markets ETF 12.5 %
iShares Core MSCI International Developed Markets ETF 6.5 %
BlackRock Tactical Opportunities Fund, Class K 4.5 %
iShares MSCI Canada ETF 2.3 %
iShares Core MSCI EAFE ETF 1.9 %
iShares Russell 2000 ETF 1.5 %
iShares MSCI EAFE Small-Cap ETF 1.0 %
BlackRock Diversified Fixed Income Fund, Class K 0.8 %
(b)Excludes short-term securities.
[1]
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[2]
Annualized.
[3]
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[4]
Annualized.
[5]
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[6]
Annualized.
[7] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[8] Annualized.
[9]
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[10]
Annualized.
[11] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[12] Annualized.
[13] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[14] Annualized.
[15] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[16] Annualized.
[17] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[18] Annualized.
[19] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[20] Annualized.
[21]
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[22]
Annualized.
[23]
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[24]
Annualized.
[25] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[26] Annualized.
[27] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[28] Annualized.
[29]
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[30]
Annualized.
[31] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[32] Annualized.
[33] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[34] Annualized.
[35] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[36] Annualized.
[37] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[38] Annualized.
[39] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[40] Annualized.
[41] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[42] Annualized.
[43] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[44] Annualized.
[45] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[46] Annualized.
[47]
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[48]
Annualized.
[49] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[50] Annualized.
[51] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[52] Annualized.
[53] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[54] Annualized.
[55] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[56] Annualized.
[57] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[58] Annualized.
[59]
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[60]
Annualized.
[61] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[62] Annualized.
[63] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[64] Annualized.
[65] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[66] Annualized.
[67] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[68] Annualized.
[69] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[70] Annualized.
[71] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[72] Annualized.
[73] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[74] Annualized.
[75] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[76] Annualized.
[77] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[78] Annualized.
[79] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[80] Annualized.
[81]
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[82] Annualized.
[83]
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[84] Annualized.
[85] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[86] Annualized.
[87] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[88] Annualized.
[89] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[90] Annualized.
[91] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[92] Annualized.
[93] Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[94] Annualized.
[95]
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[96]
Annualized.
[97]
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[98]
Annualized.
[99]
Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.
[100]
Annualized.