Investor P [Member] Expense Example - Investor P - BLACKROCK LIFEPATH INDEX RETIREMENT FUND - Investor P Shares	Dec. 31, 2025 USD ($)
Prospectus [Line Items]
Expense Example, with Redemption, 1 Year	$ 563
Expense Example, with Redemption, 3 Years	648
Expense Example, with Redemption, 5 Years	741
Expense Example, with Redemption, 10 Years	$ 1,014

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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