v3.26.1
Shareholder Report
 6 Months Ended
Jun. 30, 2026
USD ($)
$ / shares
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name Legg Mason Partners Investment Trust
Entity Central Index Key 0000880366
Entity Investment Company Type N-1A
Document Period End Date Jun. 30, 2026
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Class 1  
Shareholder Report [Line Items]  
Fund Name ClearBridge Dividend Strategy Fund
Class Name Class 1
Trading Symbol LCBOX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about ClearBridge Dividend Strategy Fund for the period  January 1, 2026, to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at 877-6LM-FUND/656-3863.
Additional Information Phone Number 877-6LM-FUND/656-3863
Additional Information Website https://www.franklintempleton.com/regulatory-fund-documents
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*,†
Class 1
$36
0.70%
[1],[2]
Expenses Paid, Amount $ 36
Expense Ratio, Percent 0.70%
Net Assets $ 9,200,801,210
Holdings Count | $ / shares 53
Investment Company Portfolio Turnover 14.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of June 30, 2026)
Total Net Assets
$9,200,801,210
Total Number of Portfolio Holdings
53
Portfolio Turnover Rate
14%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (as of June 30, 2026)
Portfolio Composition*,† (% of Total Investments)
image
 [3],[4]
Updated Prospectus Web Address https://www.franklintempleton.com/regulatory-fund-documents
Class A  
Shareholder Report [Line Items]  
Fund Name ClearBridge Dividend Strategy Fund
Class Name Class A
Trading Symbol SOPAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about ClearBridge Dividend Strategy Fund for the period  January 1, 2026, to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at 877-6LM-FUND/656-3863.
Additional Information Phone Number 877-6LM-FUND/656-3863
Additional Information Website https://www.franklintempleton.com/regulatory-fund-documents
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*,†
Class A
$51
0.99%
[5],[6]
Expenses Paid, Amount $ 51
Expense Ratio, Percent 0.99%
Net Assets $ 9,200,801,210
Holdings Count | $ / shares 53
Investment Company Portfolio Turnover 14.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of June 30, 2026)
Total Net Assets
$9,200,801,210
Total Number of Portfolio Holdings
53
Portfolio Turnover Rate
14%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (as of June 30, 2026)
Portfolio Composition*,† (% of Total Investments)
image
 [7],[8]
Updated Prospectus Web Address https://www.franklintempleton.com/regulatory-fund-documents
Class C  
Shareholder Report [Line Items]  
Fund Name ClearBridge Dividend Strategy Fund
Class Name Class C
Trading Symbol SBPLX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about ClearBridge Dividend Strategy Fund for the period  January 1, 2026, to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at 877-6LM-FUND/656-3863.
Additional Information Phone Number 877-6LM-FUND/656-3863
Additional Information Website https://www.franklintempleton.com/regulatory-fund-documents
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*,†
Class C
$89
1.75%
[9],[10]
Expenses Paid, Amount $ 89
Expense Ratio, Percent 1.75%
Net Assets $ 9,200,801,210
Holdings Count | $ / shares 53
Investment Company Portfolio Turnover 14.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of June 30, 2026)
Total Net Assets
$9,200,801,210
Total Number of Portfolio Holdings
53
Portfolio Turnover Rate
14%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (as of June 30, 2026)
Portfolio Composition*,† (% of Total Investments)
image
 [11],[12]
Updated Prospectus Web Address https://www.franklintempleton.com/regulatory-fund-documents
Class FI  
Shareholder Report [Line Items]  
Fund Name ClearBridge Dividend Strategy Fund
Class Name Class FI
Trading Symbol LBRIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about ClearBridge Dividend Strategy Fund for the period  January 1, 2026, to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at 877-6LM-FUND/656-3863.
Additional Information Phone Number 877-6LM-FUND/656-3863
Additional Information Website https://www.franklintempleton.com/regulatory-fund-documents
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*,†
Class FI
$46
0.90%
[13],[14]
Expenses Paid, Amount $ 46
Expense Ratio, Percent 0.90%
Net Assets $ 9,200,801,210
Holdings Count | $ / shares 53
Investment Company Portfolio Turnover 14.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of June 30, 2026)
Total Net Assets
$9,200,801,210
Total Number of Portfolio Holdings
53
Portfolio Turnover Rate
14%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (as of June 30, 2026)
Portfolio Composition*,† (% of Total Investments)
image
 [15],[16]
Updated Prospectus Web Address https://www.franklintempleton.com/regulatory-fund-documents
Class R  
Shareholder Report [Line Items]  
Fund Name ClearBridge Dividend Strategy Fund
Class Name Class R
Trading Symbol LMMRX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about ClearBridge Dividend Strategy Fund for the period  January 1, 2026, to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at 877-6LM-FUND/656-3863.
Additional Information Phone Number 877-6LM-FUND/656-3863
Additional Information Website https://www.franklintempleton.com/regulatory-fund-documents
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*,†
Class R
$69
1.35%
[17],[18]
Expenses Paid, Amount $ 69
Expense Ratio, Percent 1.35%
Net Assets $ 9,200,801,210
Holdings Count | $ / shares 53
Investment Company Portfolio Turnover 14.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of June 30, 2026)
Total Net Assets
$9,200,801,210
Total Number of Portfolio Holdings
53
Portfolio Turnover Rate
14%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (as of June 30, 2026)
Portfolio Composition*,† (% of Total Investments)
image
 [19],[20]
Updated Prospectus Web Address https://www.franklintempleton.com/regulatory-fund-documents
Class I  
Shareholder Report [Line Items]  
Fund Name ClearBridge Dividend Strategy Fund
Class Name Class I
Trading Symbol SOPYX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about ClearBridge Dividend Strategy Fund for the period  January 1, 2026, to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at 877-6LM-FUND/656-3863.
Additional Information Phone Number 877-6LM-FUND/656-3863
Additional Information Website https://www.franklintempleton.com/regulatory-fund-documents
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*,†
Class I
$37
0.73%
[21],[22]
Expenses Paid, Amount $ 37
Expense Ratio, Percent 0.73%
Net Assets $ 9,200,801,210
Holdings Count | $ / shares 53
Investment Company Portfolio Turnover 14.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of June 30, 2026)
Total Net Assets
$9,200,801,210
Total Number of Portfolio Holdings
53
Portfolio Turnover Rate
14%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (as of June 30, 2026)
Portfolio Composition*,† (% of Total Investments)
image
 [23],[24]
Updated Prospectus Web Address https://www.franklintempleton.com/regulatory-fund-documents
Class IS  
Shareholder Report [Line Items]  
Fund Name ClearBridge Dividend Strategy Fund
Class Name Class IS
Trading Symbol LCBEX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about ClearBridge Dividend Strategy Fund for the period  January 1, 2026, to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at 877-6LM-FUND/656-3863.
Additional Information Phone Number 877-6LM-FUND/656-3863
Additional Information Website https://www.franklintempleton.com/regulatory-fund-documents
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*,†
Class IS
$33
0.65%
[25],[26]
Expenses Paid, Amount $ 33
Expense Ratio, Percent 0.65%
Net Assets $ 9,200,801,210
Holdings Count | $ / shares 53
Investment Company Portfolio Turnover 14.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of June 30, 2026)
Total Net Assets
$9,200,801,210
Total Number of Portfolio Holdings
53
Portfolio Turnover Rate
14%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (as of June 30, 2026)
Portfolio Composition*,† (% of Total Investments)
image
 [27],[28]
Updated Prospectus Web Address https://www.franklintempleton.com/regulatory-fund-documents
[1]
* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.
[2]
† Annualized.
[3]
* Does not include derivatives, except purchased options, if any.  
[4]
† Certain categories may represent less than 0.1%.
[5]
* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.
[6]
† Annualized.
[7]
* Does not include derivatives, except purchased options, if any.  
[8]
† Certain categories may represent less than 0.1%.
[9]
* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.
[10]
† Annualized.
[11]
* Does not include derivatives, except purchased options, if any.  
[12]
† Certain categories may represent less than 0.1%.
[13]
* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.
[14]
† Annualized.
[15]
* Does not include derivatives, except purchased options, if any.  
[16]
† Certain categories may represent less than 0.1%.
[17]
* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.
[18]
† Annualized.
[19]
* Does not include derivatives, except purchased options, if any.  
[20]
† Certain categories may represent less than 0.1%.
[21]
* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.
[22]
† Annualized.
[23]
* Does not include derivatives, except purchased options, if any.  
[24]
† Certain categories may represent less than 0.1%.
[25]
* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.
[26]
† Annualized.
[27]
* Does not include derivatives, except purchased options, if any.  
[28]
† Certain categories may represent less than 0.1%.