BlackRock Retirement Income 2030 Fund S000069110 [Member] 33.34% MSCI World High Dividend Yield Index (Net)/33.33% Bloomberg U.S. Corporate High Yield 2% Issuer Capped Index/33.33% Bloomberg U.S. Aggregate Bond Index (Reflects no deduction for fees, expenses or taxes, except for withholding taxes on reinvested dividends for net indexes) Thirty Three Thirty Four MSCI World High Dividend Yield Index Net 33 33 Bloomberg U S Corporate High Yield 2 Issuer Capped Index 33 33 Bloomberg U S Aggregate Bond Index [Member] MSCI World Index (Net) (Reflects no deduction for fees, expenses or taxes, except for withholding taxes on reinvested dividends) MSCI World Index Net [Member] 50% MSCI World Index (Net)/50% Bloomberg U.S. Aggregate Bond Index (Reflects no deduction for fees, expenses or taxes, except for withholding taxes on reinvested dividends for net indexes) Fifty MSCI World Index Net 50 Bloomberg U S Aggregate Bond Index [Member] Bloomberg U.S. Aggregate Bond Index (Reflects no deduction for fees, expenses or taxes) Bloomberg U S Aggregate Bond Index [Member] Institutional C000220895 [Member] Investor A C000220896 [Member] Managed Distribution Tax Risk [Member] Model Risk [Member] Limited Term Risk [Member] Allocation Risk [Member] Collateralized Debt Obligations Risk [Member] Convertible Securities Risk [Member] Corporate Loans Risk [Member] Counterparty Risk [Member] Covered Call Risk [Member] Debt Securities Risk [Member] Derivatives Risks [Member] Distressed Securities Risk [Member] Dollar Rolls Risk [Member] Emerging Markets Risk [Member] Equity Securities Risk [Member] Foreign Securities Risk [Member] High Yield Bonds Risk [Member] Illiquid Investments Risk [Member] Indexed Securities Risk [Member] Investment in Other Investment Companies Risk [Member] Large Capitalization Companies Risk [Member] Leverage Risk [Member] Market Risk and Selection Risk [Member] Mortgage and Asset Backed Securities Risks [Member] New Issues Risk [Member] Operational and Technology Risks [Member] Preferred Securities Risk [Member] Reference Rate Replacement Risk [Member] REIT Investment Risk [Member] Repurchase Agreements and Purchase and Sale Contracts Risk [Member] Restricted Securities Risk [Member] Risk of Investing in the United States [Member] Structured Securities Risk [Member] U S Government Issuer Risk [Member] Variable and Floating Rate Instrument Risk [Member] Affiliated Fund Risk [Member]