v3.25.2
Shareholder Report, Holdings (Details)
Jun. 30, 2025
C000011998 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 30.40% [1]
C000011998 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.90% [1]
C000011998 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 9.90% [1]
C000011998 [Member] | iShares 0 5 Year TIPS Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.40% [1]
C000011998 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 5.40% [1]
C000011998 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.70% [1]
C000011998 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60% [1]
C000011998 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [1]
C000011998 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [1]
C000011998 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.70% [1]
C000011998 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.50% [2]
C000011998 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 35.00% [2]
C000011998 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 55.20% [2]
C000011998 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (2.70%) [2]
C000011997 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 30.40% [3]
C000011997 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.90% [3]
C000011997 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 9.90% [3]
C000011997 [Member] | iShares 0 5 Year TIPS Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.40% [3]
C000011997 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 5.40% [3]
C000011997 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.70% [3]
C000011997 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60% [3]
C000011997 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [3]
C000011997 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [3]
C000011997 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.70% [3]
C000011997 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.50% [4]
C000011997 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 35.00% [4]
C000011997 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 55.20% [4]
C000011997 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (2.70%) [4]
C000088835 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 30.40% [5]
C000088835 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.90% [5]
C000088835 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 9.90% [5]
C000088835 [Member] | iShares 0 5 Year TIPS Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.40% [5]
C000088835 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 5.40% [5]
C000088835 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.70% [5]
C000088835 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60% [5]
C000088835 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [5]
C000088835 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [5]
C000088835 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.70% [5]
C000088835 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.50% [6]
C000088835 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 35.00% [6]
C000088835 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 55.20% [6]
C000088835 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (2.70%) [6]
C000051481 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 30.40% [7]
C000051481 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.90% [7]
C000051481 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 9.90% [7]
C000051481 [Member] | iShares 0 5 Year TIPS Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.40% [7]
C000051481 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 5.40% [7]
C000051481 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.70% [7]
C000051481 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60% [7]
C000051481 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [7]
C000051481 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [7]
C000051481 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.70% [7]
C000051481 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.50% [8]
C000051481 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 35.00% [8]
C000051481 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 55.20% [8]
C000051481 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (2.70%) [8]
C000082487 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 30.40% [9]
C000082487 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.90% [9]
C000082487 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 9.90% [9]
C000082487 [Member] | iShares 0 5 Year TIPS Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.40% [9]
C000082487 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 5.40% [9]
C000082487 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.70% [9]
C000082487 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60% [9]
C000082487 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [9]
C000082487 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [9]
C000082487 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.70% [9]
C000082487 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.50% [10]
C000082487 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 35.00% [10]
C000082487 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 55.20% [10]
C000082487 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (2.70%) [10]
C000012000 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 38.10% [11]
C000012000 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 15.20% [11]
C000012000 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [11]
C000012000 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.70% [11]
C000012000 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [11]
C000012000 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.30% [11]
C000012000 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.90% [11]
C000012000 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.80% [11]
C000012000 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.60% [11]
C000012000 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.50% [11]
C000012000 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 16.70% [12]
C000012000 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.10% [12]
C000012000 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 73.10% [12]
C000012000 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (9.90%) [12]
C000011999 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 38.10% [13]
C000011999 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 15.20% [13]
C000011999 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [13]
C000011999 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.70% [13]
C000011999 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [13]
C000011999 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.30% [13]
C000011999 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.90% [13]
C000011999 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.80% [13]
C000011999 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.60% [13]
C000011999 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.50% [13]
C000011999 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 16.70% [14]
C000011999 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.10% [14]
C000011999 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 73.10% [14]
C000011999 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (9.90%) [14]
C000088838 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 38.10% [15]
C000088838 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 15.20% [15]
C000088838 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [15]
C000088838 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.70% [15]
C000088838 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [15]
C000088838 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.30% [15]
C000088838 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.90% [15]
C000088838 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.80% [15]
C000088838 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.60% [15]
C000088838 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.50% [15]
C000088838 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 16.70% [16]
C000088838 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.10% [16]
C000088838 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 73.10% [16]
C000088838 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (9.90%) [16]
C000051482 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 38.10% [17]
C000051482 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 15.20% [17]
C000051482 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [17]
C000051482 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.70% [17]
C000051482 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [17]
C000051482 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.30% [17]
C000051482 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.90% [17]
C000051482 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.80% [17]
C000051482 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.60% [17]
C000051482 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.50% [17]
C000051482 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 16.70% [18]
C000051482 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.10% [18]
C000051482 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 73.10% [18]
C000051482 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (9.90%) [18]
C000082488 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 38.10% [19]
C000082488 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 15.20% [19]
C000082488 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [19]
C000082488 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.70% [19]
C000082488 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [19]
C000082488 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.30% [19]
C000082488 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.90% [19]
C000082488 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.80% [19]
C000082488 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.60% [19]
C000082488 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.50% [19]
C000082488 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 16.70% [20]
C000082488 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.10% [20]
C000082488 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 73.10% [20]
C000082488 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (9.90%) [20]
C000012002 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 23.90% [21]
C000012002 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 39.40% [21]
C000012002 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.30% [21]
C000012002 [Member] | iShares 0 5 Year TIPS Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 9.80% [21]
C000012002 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.00% [21]
C000012002 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.80% [21]
C000012002 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.20% [21]
C000012002 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20% [21]
C000012002 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.90% [21]
C000012002 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20% [21]
C000012002 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.50% [22]
C000012002 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 49.20% [22]
C000012002 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 43.70% [22]
C000012002 [Member] | Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.60% [22]
C000012001 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 23.90% [23]
C000012001 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 39.40% [23]
C000012001 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.30% [23]
C000012001 [Member] | iShares 0 5 Year TIPS Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 9.80% [23]
C000012001 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.00% [23]
C000012001 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.80% [23]
C000012001 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.20% [23]
C000012001 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20% [23]
C000012001 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.90% [23]
C000012001 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20% [23]
C000012001 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.50% [24]
C000012001 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 49.20% [24]
C000012001 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 43.70% [24]
C000012001 [Member] | Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.60% [24]
C000088841 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 23.90% [25]
C000088841 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 39.40% [25]
C000088841 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.30% [25]
C000088841 [Member] | iShares 0 5 Year TIPS Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 9.80% [25]
C000088841 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.00% [25]
C000088841 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.80% [25]
C000088841 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.20% [25]
C000088841 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20% [25]
C000088841 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.90% [25]
C000088841 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20% [25]
C000088841 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.50% [26]
C000088841 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 49.20% [26]
C000088841 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 43.70% [26]
C000088841 [Member] | Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.60% [26]
C000051483 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 23.90% [27]
C000051483 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 39.40% [27]
C000051483 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.30% [27]
C000051483 [Member] | iShares 0 5 Year TIPS Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 9.80% [27]
C000051483 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.00% [27]
C000051483 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.80% [27]
C000051483 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.20% [27]
C000051483 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20% [27]
C000051483 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.90% [27]
C000051483 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20% [27]
C000051483 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.50% [28]
C000051483 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 49.20% [28]
C000051483 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 43.70% [28]
C000051483 [Member] | Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.60% [28]
C000082489 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 23.90% [29]
C000082489 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 39.40% [29]
C000082489 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.30% [29]
C000082489 [Member] | iShares 0 5 Year TIPS Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 9.80% [29]
C000082489 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.00% [29]
C000082489 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.80% [29]
C000082489 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.20% [29]
C000082489 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20% [29]
C000082489 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.90% [29]
C000082489 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20% [29]
C000082489 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.50% [30]
C000082489 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 49.20% [30]
C000082489 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 43.70% [30]
C000082489 [Member] | Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.60% [30]
C000063261 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 45.60% [31]
C000063261 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.50% [31]
C000063261 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [31]
C000063261 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.10% [31]
C000063261 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [31]
C000063261 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [31]
C000063261 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.90% [31]
C000063261 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.90% [31]
C000063261 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.00% [31]
C000063261 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.50% [31]
C000063261 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.40% [32]
C000063261 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.40% [32]
C000063261 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 86.10% [32]
C000063261 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (13.90%) [32]
C000063260 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 45.60% [33]
C000063260 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.50% [33]
C000063260 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [33]
C000063260 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.10% [33]
C000063260 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [33]
C000063260 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [33]
C000063260 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.90% [33]
C000063260 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.90% [33]
C000063260 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.00% [33]
C000063260 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.50% [33]
C000063260 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.40% [34]
C000063260 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.40% [34]
C000063260 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 86.10% [34]
C000063260 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (13.90%) [34]
C000088844 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 45.60% [35]
C000088844 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.50% [35]
C000088844 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [35]
C000088844 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.10% [35]
C000088844 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [35]
C000088844 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [35]
C000088844 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.90% [35]
C000088844 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.90% [35]
C000088844 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.00% [35]
C000088844 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.50% [35]
C000088844 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.40% [36]
C000088844 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.40% [36]
C000088844 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 86.10% [36]
C000088844 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (13.90%) [36]
C000063262 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 45.60% [37]
C000063262 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.50% [37]
C000063262 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [37]
C000063262 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.10% [37]
C000063262 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [37]
C000063262 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [37]
C000063262 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.90% [37]
C000063262 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.90% [37]
C000063262 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.00% [37]
C000063262 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.50% [37]
C000063262 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.40% [38]
C000063262 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.40% [38]
C000063262 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 86.10% [38]
C000063262 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (13.90%) [38]
C000082490 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 45.60% [39]
C000082490 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.50% [39]
C000082490 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [39]
C000082490 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.10% [39]
C000082490 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [39]
C000082490 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [39]
C000082490 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.90% [39]
C000082490 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.90% [39]
C000082490 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.00% [39]
C000082490 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.50% [39]
C000082490 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.40% [40]
C000082490 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.40% [40]
C000082490 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 86.10% [40]
C000082490 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (13.90%) [40]
C000089955 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 36.20% [41]
C000089955 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.70% [41]
C000089955 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.30% [41]
C000089955 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.40% [41]
C000089955 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [41]
C000089955 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [41]
C000089955 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [41]
C000089955 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.70% [41]
C000089955 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [41]
C000089955 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30% [41]
C000089955 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.50% [42]
C000089955 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 25.90% [42]
C000089955 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 66.30% [42]
C000089955 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (12.70%) [42]
C000089953 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 36.20% [43]
C000089953 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.70% [43]
C000089953 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.30% [43]
C000089953 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.40% [43]
C000089953 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [43]
C000089953 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [43]
C000089953 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [43]
C000089953 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.70% [43]
C000089953 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [43]
C000089953 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30% [43]
C000089953 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.50% [44]
C000089953 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 25.90% [44]
C000089953 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 66.30% [44]
C000089953 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (12.70%) [44]
C000089954 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 36.20% [45]
C000089954 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.70% [45]
C000089954 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.30% [45]
C000089954 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.40% [45]
C000089954 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [45]
C000089954 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [45]
C000089954 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [45]
C000089954 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.70% [45]
C000089954 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [45]
C000089954 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30% [45]
C000089954 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.50% [46]
C000089954 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 25.90% [46]
C000089954 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 66.30% [46]
C000089954 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (12.70%) [46]
C000089956 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 36.20% [47]
C000089956 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.70% [47]
C000089956 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.30% [47]
C000089956 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.40% [47]
C000089956 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [47]
C000089956 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [47]
C000089956 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [47]
C000089956 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.70% [47]
C000089956 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [47]
C000089956 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30% [47]
C000089956 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.50% [48]
C000089956 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 25.90% [48]
C000089956 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 66.30% [48]
C000089956 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (12.70%) [48]
C000089952 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 36.20% [49]
C000089952 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.70% [49]
C000089952 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.30% [49]
C000089952 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.40% [49]
C000089952 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [49]
C000089952 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [49]
C000089952 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [49]
C000089952 [Member] | iShares Global Infrastructure ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.70% [49]
C000089952 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [49]
C000089952 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30% [49]
C000089952 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 20.50% [50]
C000089952 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 25.90% [50]
C000089952 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 66.30% [50]
C000089952 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (12.70%) [50]
C000089959 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 41.10% [51]
C000089959 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.50% [51]
C000089959 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 15.00% [51]
C000089959 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.80% [51]
C000089959 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [51]
C000089959 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.50% [51]
C000089959 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.60% [51]
C000089959 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.60% [51]
C000089959 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.00% [51]
C000089959 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.60% [51]
C000089959 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.20% [52]
C000089959 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.20% [52]
C000089959 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 79.70% [52]
C000089959 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (15.10%) [52]
C000089957 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 41.10% [53]
C000089957 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.50% [53]
C000089957 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 15.00% [53]
C000089957 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.80% [53]
C000089957 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [53]
C000089957 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.50% [53]
C000089957 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.60% [53]
C000089957 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.60% [53]
C000089957 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.00% [53]
C000089957 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.60% [53]
C000089957 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.20% [54]
C000089957 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.20% [54]
C000089957 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 79.70% [54]
C000089957 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (15.10%) [54]
C000089958 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 41.10% [55]
C000089958 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.50% [55]
C000089958 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 15.00% [55]
C000089958 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.80% [55]
C000089958 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [55]
C000089958 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.50% [55]
C000089958 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.60% [55]
C000089958 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.60% [55]
C000089958 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.00% [55]
C000089958 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.60% [55]
C000089958 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.20% [56]
C000089958 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.20% [56]
C000089958 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 79.70% [56]
C000089958 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (15.10%) [56]
C000089960 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 41.10% [57]
C000089960 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.50% [57]
C000089960 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 15.00% [57]
C000089960 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.80% [57]
C000089960 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [57]
C000089960 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.50% [57]
C000089960 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.60% [57]
C000089960 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.60% [57]
C000089960 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.00% [57]
C000089960 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.60% [57]
C000089960 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.20% [58]
C000089960 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.20% [58]
C000089960 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 79.70% [58]
C000089960 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (15.10%) [58]
C000089961 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 41.10% [59]
C000089961 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.50% [59]
C000089961 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 15.00% [59]
C000089961 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.80% [59]
C000089961 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [59]
C000089961 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.50% [59]
C000089961 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.60% [59]
C000089961 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.60% [59]
C000089961 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.00% [59]
C000089961 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.60% [59]
C000089961 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.20% [60]
C000089961 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.20% [60]
C000089961 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 79.70% [60]
C000089961 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (15.10%) [60]
C000089964 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.10% [61]
C000089964 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.40% [61]
C000089964 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [61]
C000089964 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.80% [61]
C000089964 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [61]
C000089964 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [61]
C000089964 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.70% [61]
C000089964 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.30% [61]
C000089964 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.40% [61]
C000089964 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [61]
C000089964 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.20% [62]
C000089964 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.70% [62]
C000089964 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 92.40% [62]
C000089964 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (6.30%) [62]
C000089962 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.10% [63]
C000089962 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.40% [63]
C000089962 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [63]
C000089962 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.80% [63]
C000089962 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [63]
C000089962 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [63]
C000089962 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.70% [63]
C000089962 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.30% [63]
C000089962 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.40% [63]
C000089962 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [63]
C000089962 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.20% [64]
C000089962 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.70% [64]
C000089962 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 92.40% [64]
C000089962 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (6.30%) [64]
C000089963 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.10% [65]
C000089963 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.40% [65]
C000089963 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [65]
C000089963 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.80% [65]
C000089963 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [65]
C000089963 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [65]
C000089963 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.70% [65]
C000089963 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.30% [65]
C000089963 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.40% [65]
C000089963 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [65]
C000089963 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.20% [66]
C000089963 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.70% [66]
C000089963 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 92.40% [66]
C000089963 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (6.30%) [66]
C000089965 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.10% [67]
C000089965 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.40% [67]
C000089965 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [67]
C000089965 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.80% [67]
C000089965 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [67]
C000089965 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [67]
C000089965 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.70% [67]
C000089965 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.30% [67]
C000089965 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.40% [67]
C000089965 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [67]
C000089965 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.20% [68]
C000089965 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.70% [68]
C000089965 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 92.40% [68]
C000089965 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (6.30%) [68]
C000089966 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.10% [69]
C000089966 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.40% [69]
C000089966 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [69]
C000089966 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.80% [69]
C000089966 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [69]
C000089966 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [69]
C000089966 [Member] | BlackRock Real Estate Securities Fund [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.70% [69]
C000089966 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.30% [69]
C000089966 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.40% [69]
C000089966 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [69]
C000089966 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.20% [70]
C000089966 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.70% [70]
C000089966 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 92.40% [70]
C000089966 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (6.30%) [70]
C000187070 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.40% [71]
C000187070 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60% [71]
C000187070 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [71]
C000187070 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.80% [71]
C000187070 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [71]
C000187070 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [71]
C000187070 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [71]
C000187070 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.90% [71]
C000187070 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [71]
C000187070 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [71]
C000187070 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.60% [72]
C000187070 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.40% [72]
C000187070 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 93.50% [72]
C000187070 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (6.50%) [72]
C000187068 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.40% [73]
C000187068 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60% [73]
C000187068 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [73]
C000187068 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.80% [73]
C000187068 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [73]
C000187068 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [73]
C000187068 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [73]
C000187068 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.90% [73]
C000187068 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [73]
C000187068 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [73]
C000187068 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.60% [74]
C000187068 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.40% [74]
C000187068 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 93.50% [74]
C000187068 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (6.50%) [74]
C000187069 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.40% [75]
C000187069 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60% [75]
C000187069 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [75]
C000187069 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.80% [75]
C000187069 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [75]
C000187069 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [75]
C000187069 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [75]
C000187069 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.90% [75]
C000187069 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [75]
C000187069 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [75]
C000187069 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.60% [76]
C000187069 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.40% [76]
C000187069 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 93.50% [76]
C000187069 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (6.50%) [76]
C000187072 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.40% [77]
C000187072 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60% [77]
C000187072 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [77]
C000187072 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.80% [77]
C000187072 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [77]
C000187072 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [77]
C000187072 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [77]
C000187072 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.90% [77]
C000187072 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [77]
C000187072 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [77]
C000187072 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.60% [78]
C000187072 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.40% [78]
C000187072 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 93.50% [78]
C000187072 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (6.50%) [78]
C000187071 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.40% [79]
C000187071 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60% [79]
C000187071 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [79]
C000187071 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.80% [79]
C000187071 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [79]
C000187071 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [79]
C000187071 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [79]
C000187071 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.90% [79]
C000187071 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [79]
C000187071 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [79]
C000187071 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.60% [80]
C000187071 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.40% [80]
C000187071 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 93.50% [80]
C000187071 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (6.50%) [80]
C000213846 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.20% [81]
C000213846 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [81]
C000213846 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [81]
C000213846 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.80% [81]
C000213846 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [81]
C000213846 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.40% [81]
C000213846 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [81]
C000213846 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.90% [81]
C000213846 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.10% [81]
C000213846 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.20% [81]
C000213846 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.90% [82]
C000213846 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.30% [82]
C000213846 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 93.80% [82]
C000213846 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (8.00%) [82]
C000213845 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.20% [83]
C000213845 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [83]
C000213845 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [83]
C000213845 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.80% [83]
C000213845 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [83]
C000213845 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.40% [83]
C000213845 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [83]
C000213845 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.90% [83]
C000213845 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.10% [83]
C000213845 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.20% [83]
C000213845 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.90% [84]
C000213845 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.30% [84]
C000213845 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 93.80% [84]
C000213845 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (8.00%) [84]
C000213843 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.20% [85]
C000213843 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [85]
C000213843 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [85]
C000213843 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.80% [85]
C000213843 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [85]
C000213843 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.40% [85]
C000213843 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [85]
C000213843 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.90% [85]
C000213843 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.10% [85]
C000213843 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.20% [85]
C000213843 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.90% [86]
C000213843 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.30% [86]
C000213843 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 93.80% [86]
C000213843 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (8.00%) [86]
C000213844 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.20% [87]
C000213844 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [87]
C000213844 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [87]
C000213844 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.80% [87]
C000213844 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [87]
C000213844 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.40% [87]
C000213844 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [87]
C000213844 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.90% [87]
C000213844 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.10% [87]
C000213844 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.20% [87]
C000213844 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.90% [88]
C000213844 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.30% [88]
C000213844 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 93.80% [88]
C000213844 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (8.00%) [88]
C000213847 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.20% [89]
C000213847 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [89]
C000213847 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.90% [89]
C000213847 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.80% [89]
C000213847 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.90% [89]
C000213847 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.40% [89]
C000213847 [Member] | iShares Broad USD Investment Grade Corporate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80% [89]
C000213847 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.90% [89]
C000213847 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.10% [89]
C000213847 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.20% [89]
C000213847 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.90% [90]
C000213847 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.30% [90]
C000213847 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 93.80% [90]
C000213847 [Member] | Liabilities in Excess of Other Assets [Member]  
Holdings [Line Items]  
Percent of Net Asset Value (8.00%) [90]
C000251825 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.80% [91]
C000251825 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90% [91]
C000251825 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 15.00% [91]
C000251825 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.00% [91]
C000251825 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.80% [91]
C000251825 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.00% [91]
C000251825 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.70% [91]
C000251825 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [91]
C000251825 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [91]
C000251825 [Member] | iShares Core MSCI EAFE ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [91]
C000251825 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90% [92]
C000251825 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.80% [92]
C000251825 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 96.80% [92]
C000251825 [Member] | Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.50% [92]
C000251826 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.80% [93]
C000251826 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90% [93]
C000251826 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 15.00% [93]
C000251826 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.00% [93]
C000251826 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.80% [93]
C000251826 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.00% [93]
C000251826 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.70% [93]
C000251826 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [93]
C000251826 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [93]
C000251826 [Member] | iShares Core MSCI EAFE ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [93]
C000251826 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90% [94]
C000251826 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.80% [94]
C000251826 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 96.80% [94]
C000251826 [Member] | Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.50% [94]
C000251827 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.80% [95]
C000251827 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90% [95]
C000251827 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 15.00% [95]
C000251827 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.00% [95]
C000251827 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.80% [95]
C000251827 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.00% [95]
C000251827 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.70% [95]
C000251827 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [95]
C000251827 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [95]
C000251827 [Member] | iShares Core MSCI EAFE ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [95]
C000251827 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90% [96]
C000251827 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.80% [96]
C000251827 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 96.80% [96]
C000251827 [Member] | Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.50% [96]
C000251828 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.80% [97]
C000251828 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90% [97]
C000251828 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 15.00% [97]
C000251828 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.00% [97]
C000251828 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.80% [97]
C000251828 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.00% [97]
C000251828 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.70% [97]
C000251828 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [97]
C000251828 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [97]
C000251828 [Member] | iShares Core MSCI EAFE ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [97]
C000251828 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90% [98]
C000251828 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.80% [98]
C000251828 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 96.80% [98]
C000251828 [Member] | Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.50% [98]
C000251824 [Member] | Diversified Equity Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.80% [99]
C000251824 [Member] | BlackRock Diversified Fixed Income Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90% [99]
C000251824 [Member] | International Tilts Master Portfolio [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 15.00% [99]
C000251824 [Member] | iShares Core MSCI Emerging Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.00% [99]
C000251824 [Member] | BlackRock Tactical Opportunities Fund Class K [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.80% [99]
C000251824 [Member] | iShares MSCI EAFE Small Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.00% [99]
C000251824 [Member] | iShares Core MSCI International Developed Markets ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.70% [99]
C000251824 [Member] | iShares MSCI Canada ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20% [99]
C000251824 [Member] | iShares Russell 2000 ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [99]
C000251824 [Member] | iShares Core MSCI EAFE ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.50% [99]
C000251824 [Member] | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90% [100]
C000251824 [Member] | Fixed Income Funds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.80% [100]
C000251824 [Member] | Equity Funds Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 96.80% [100]
C000251824 [Member] | Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.50% [100]
[1] Excludes short-term securities.
[2] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[3] Excludes short-term securities.
[4] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[5] Excludes short-term securities.
[6] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[7] Excludes short-term securities.
[8] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[9] Excludes short-term securities.
[10] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[11] Excludes short-term securities.
[12] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[13] Excludes short-term securities.
[14] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[15] Excludes short-term securities.
[16] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[17] Excludes short-term securities.
[18] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[19] Excludes short-term securities.
[20] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[21] Excludes short-term securities.
[22] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[23] Excludes short-term securities.
[24] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[25] Excludes short-term securities.
[26] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[27] Excludes short-term securities.
[28] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[29] Excludes short-term securities.
[30] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[31] Excludes short-term securities.
[32] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[33] Excludes short-term securities.
[34] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[35] Excludes short-term securities.
[36] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[37] Excludes short-term securities.
[38] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[39] Excludes short-term securities.
[40] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[41] Excludes short-term securities.
[42] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[43] Excludes short-term securities.
[44] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[45] Excludes short-term securities.
[46] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[47] Excludes short-term securities.
[48] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[49] Excludes short-term securities.
[50] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[51] Excludes short-term securities.
[52] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[53] Excludes short-term securities.
[54] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[55] Excludes short-term securities.
[56] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[57] Excludes short-term securities.
[58] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[59] Excludes short-term securities.
[60] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[61] Excludes short-term securities.
[62] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[63] Excludes short-term securities.
[64] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[65] Excludes short-term securities.
[66] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[67] Excludes short-term securities.
[68] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[69] Excludes short-term securities.
[70] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[71] Excludes short-term securities.
[72] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[73] Excludes short-term securities.
[74] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[75] Excludes short-term securities.
[76] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[77] Excludes short-term securities.
[78] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[79] Excludes short-term securities.
[80] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[81] Excludes short-term securities.
[82] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[83] Excludes short-term securities.
[84] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[85] Excludes short-term securities.
[86] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[87] Excludes short-term securities.
[88] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[89] Excludes short-term securities.
[90] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[91] Excludes short-term securities.
[92] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[93] Excludes short-term securities.
[94] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[95] Excludes short-term securities.
[96] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[97] Excludes short-term securities.
[98] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.
[99] Excludes short-term securities.
[100] The portfolio composition above is calculated using a methodology different than that disclosed in the Fund's prospectus.