v3.26.1
Investor A, Institutional [Member] Expense Example - Investor A, Institutional - BLACKROCK LIFEPATH INDEX 2045 FUND
Dec. 31, 2025
USD ($)
Investor A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year $ 40
Expense Example, with Redemption, 3 Years 134
Expense Example, with Redemption, 5 Years 237
Expense Example, with Redemption, 10 Years 538
Institutional Shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 14
Expense Example, with Redemption, 3 Years 54
Expense Example, with Redemption, 5 Years 97
Expense Example, with Redemption, 10 Years $ 226