| Form N-CSR Cover | 6 Months Ended |
| Jun. 30, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | BlackRock Funds II |
| Entity Central Index Key | 0001398078 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Jun. 30, 2024 |
| Shareholder Report | 6 Months Ended |
| Jun. 30, 2024 USD ($) Holding | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | BlackRock Funds II |
| Entity Central Index Key | 0001398078 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Jun. 30, 2024 |
| C000050721 | |
| Shareholder Report [Line Items] | |
| Fund Name | BlackRock Managed Income Fund |
| Class Name | Institutional Shares |
| Trading Symbol | BLDIX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about BlackRock Managed Income Fund (the “Fund”) for the period of January 1, 2024 to June 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Semi-Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports |
| Material Fund Change Notice [Text Block] | |
| Additional Information Phone Number | (800) 441-7762 |
| Additional Information Website | <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">blackrock.com/fundreports</span></span>" id="sjs-B20"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">blackrock.com/fundreports</span></span> |
| 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 Institutional Shares $19 0.38% |
| Expenses Paid, Amount | $ 19 |
| Expense Ratio, Percent | 0.38% |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. </span>Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles." id="sjs-B24"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">Past performance is not an indication of future results. </span>Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles. |
| Average Annual Return [Table Text Block] | Fund performance Average annual total returns Average Annual Total Returns 6-Month Total Returns 1 Year 5 Years 10 Years Institutional Shares ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 2.26 % 7.79 % 3.40 % 3.70 % Bloomberg U.S. Aggregate Bond Index ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ (0.71 ) 2.63 (0.23 ) 1.35 Customized Reference Benchmark ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 3.92 8.89 4.41 4.90 The Fund's returns shown prior to October 1, 2016, are the returns of the Fund when it followed a different investment objective and different investment strategies under the name BlackRock Investment Grade Bond Portfolio. The Customized Reference Benchmark is comprised of the returns of the Bloomberg U.S. Aggregate Bond Index (70%) and the S&P 500 ® |
| No Deduction of Taxes [Text Block] | Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. |
| Performance Table Market Index Changed [Text Block] | |
| Material Change Description [Text Block] | |
| Updated Performance Information Location [Text Block] | |
| AssetsNet | $ 750,243,707 |
| Holdings Count | Holding | 1,781 |
| InvestmentCompanyPortfolioTurnover | 36% |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ $750,243,707 Number of Portfolio Holdings ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 1,781 Portfolio Turnover Rate ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 36% |
| Holdings [Text Block] | Portfolio composition Credit quality allocation Investment Type Percent of Total Investments Footnote Reference Investment Companies ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 26.3 % Corporate Bonds ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 25.5 Asset-Backed Securities ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 19.4 Common Stocks ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 10.0 Floating Rate Loan Interests ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 10.0 Equity-Linked Notes ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 5.5 Non-Agency Mortgage-Backed Securities ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 1.5 U.S. Treasury Obligations ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 1.1 Foreign Agency Obligations ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.4 Foreign Government Obligations ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.2 Other Footnote Reference ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.1 Credit Rating Footnote Reference Percent of Total Investments Footnote Reference AAA/Aaa Footnote Reference ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 25.7 % AA/Aa ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 8.7 A ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 25.2 BBB/Baa ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 20.4 BB/Ba ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 4.6 B ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 5.8 CCC/Caa ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.4 CC/Ca ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.1 NR ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 9.1 Footnote Description Footnote (a) Excludes short-term securities. Footnote (b) Ten largest investment types are presented. Additional investment types are found in Other. Footnote (c) For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated NR are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change. Footnote (d) The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors, individual investments and/or issuers. Using this approach, the investment adviser has deemed unrated U.S. Government Sponsored Agency Securities and U.S. Treasury Obligations to be of similar credit quality as investments rated AAA/Aaa. |
| C000050722 | |
| Shareholder Report [Line Items] | |
| Fund Name | BlackRock Managed Income Fund |
| Class Name | Investor A Shares |
| Trading Symbol | BLADX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about BlackRock Managed Income Fund (the “Fund”) for the period of January 1, 2024 to June 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Semi-Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports |
| Material Fund Change Notice [Text Block] | |
| Additional Information Phone Number | (800) 441-7762 |
| Additional Information Website | <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">blackrock.com/fundreports</span></span>" id="sjs-B45"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">blackrock.com/fundreports</span></span> |
| 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 Investor A Shares $32 0.63% |
| Expenses Paid, Amount | $ 32 |
| Expense Ratio, Percent | 0.63% |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. </span>Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles." id="sjs-B49"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">Past performance is not an indication of future results. </span>Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles. |
| Average Annual Return [Table Text Block] | Fund performance Average annual total returns Average Annual Total Returns 6-Month Total Returns 1 Year 5 Years 10 Years Investor A Shares ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 2.13 % 7.52 % 3.12 % 3.41 % Investor A Shares (with sales charge) ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ (1.95 ) 3.22 2.28 2.99 Bloomberg U.S. Aggregate Bond Index ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ (0.71 ) 2.63 (0.23 ) 1.35 Customized Reference Benchmark ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 3.92 8.89 4.41 4.90 The Fund's returns shown prior to October 1, 2016, are the returns of the Fund when it followed a different investment objective and different investment strategies under the name BlackRock Investment Grade Bond Portfolio. The Customized Reference Benchmark is comprised of the returns of the Bloomberg U.S. Aggregate Bond Index (70%) and the S&P 500 ® Assuming maximum sales charges. Average annual total returns with and without sales charges reflect reductions for service fees. |
| No Deduction of Taxes [Text Block] | Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. |
| Performance Table Market Index Changed [Text Block] | |
| Material Change Description [Text Block] | |
| Updated Performance Information Location [Text Block] | |
| AssetsNet | $ 750,243,707 |
| Holdings Count | Holding | 1,781 |
| InvestmentCompanyPortfolioTurnover | 36% |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ $750,243,707 Number of Portfolio Holdings ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 1,781 Portfolio Turnover Rate ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 36% |
| Holdings [Text Block] | Portfolio composition Credit quality allocation Investment Type Percent of Total Investments Footnote Reference Investment Companies ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 26.3 % Corporate Bonds ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 25.5 Asset-Backed Securities ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 19.4 Common Stocks ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 10.0 Floating Rate Loan Interests ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 10.0 Equity-Linked Notes ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 5.5 Non-Agency Mortgage-Backed Securities ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 1.5 U.S. Treasury Obligations ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 1.1 Foreign Agency Obligations ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.4 Foreign Government Obligations ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.2 Other Footnote Reference ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.1 Credit Rating Footnote Reference Percent of Total Investments Footnote Reference AAA/Aaa Footnote Reference ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 25.7 % AA/Aa ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 8.7 A ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 25.2 BBB/Baa ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 20.4 BB/Ba ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 4.6 B ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 5.8 CCC/Caa ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.4 CC/Ca ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.1 NR ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 9.1 Footnote Description Footnote (a) Excludes short-term securities. Footnote (b) Ten largest investment types are presented. Additional investment types are found in Other. Footnote (c) For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated NR are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change. Footnote (d) The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors, individual investments and/or issuers. Using this approach, the investment adviser has deemed unrated U.S. Government Sponsored Agency Securities and U.S. Treasury Obligations to be of similar credit quality as investments rated AAA/Aaa. |
| C000174022 | |
| Shareholder Report [Line Items] | |
| Fund Name | BlackRock Managed Income Fund |
| Class Name | Investor C Shares |
| Trading Symbol | BMICX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about BlackRock Managed Income Fund (the “Fund”) for the period of January 1, 2024 to June 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Semi-Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports |
| Material Fund Change Notice [Text Block] | |
| Additional Information Phone Number | (800) 441-7762 |
| Additional Information Website | <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">blackrock.com/fundreports</span></span>" id="sjs-B70"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">blackrock.com/fundreports</span></span> |
| 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 Investor C Shares $69 1.38% |
| Expenses Paid, Amount | $ 69 |
| Expense Ratio, Percent | 1.38% |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. </span>Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles." id="sjs-B74"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">Past performance is not an indication of future results. </span>Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles. |
| Average Annual Return [Table Text Block] | Fund performance Average annual total returns Average Annual Total Returns 6-Month Total Returns 1 Year 5 Years 10 Years Investor C Shares ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 1.75 % 6.71 % 2.36 % 2.65 % Investor C Shares (with sales charge) ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.75 5.71 2.36 2.65 Bloomberg U.S. Aggregate Bond Index ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ (0.71 ) 2.63 (0.23 ) 1.35 Customized Reference Benchmark ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 3.92 8.89 4.41 4.90 The Fund's returns shown prior to October 1, 2016, are the returns of the Fund when it followed a different investment objective and different investment strategies under the name BlackRock Investment Grade Bond Portfolio. The Customized Reference Benchmark is comprised of the returns of the Bloomberg U.S. Aggregate Bond Index (70%) and the S&P 500 ® Performance shown prior to the Investor C Shares inception date of October 3, 2016 is that of Class K Shares (which have no distribution or service fees) and was restated to reflect Investor C Shares fees. Assuming maximum sales charges. Average annual total returns with and without sales charges reflect reductions for distribution and service fees. |
| No Deduction of Taxes [Text Block] | Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. |
| Performance Table Market Index Changed [Text Block] | |
| Material Change Description [Text Block] | |
| Updated Performance Information Location [Text Block] | |
| AssetsNet | $ 750,243,707 |
| Holdings Count | Holding | 1,781 |
| InvestmentCompanyPortfolioTurnover | 36% |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ $750,243,707 Number of Portfolio Holdings ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 1,781 Portfolio Turnover Rate ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 36% |
| Holdings [Text Block] | Portfolio composition Credit quality allocation Investment Type Percent of Total Investments Footnote Reference Investment Companies ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 26.3 % Corporate Bonds ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 25.5 Asset-Backed Securities ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 19.4 Common Stocks ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 10.0 Floating Rate Loan Interests ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 10.0 Equity-Linked Notes ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 5.5 Non-Agency Mortgage-Backed Securities ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 1.5 U.S. Treasury Obligations ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 1.1 Foreign Agency Obligations ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.4 Foreign Government Obligations ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.2 Other Footnote Reference ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.1 Credit Rating Footnote Reference Percent of Total Investments Footnote Reference AAA/Aaa Footnote Reference ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 25.7 % AA/Aa ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 8.7 A ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 25.2 BBB/Baa ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 20.4 BB/Ba ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 4.6 B ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 5.8 CCC/Caa ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.4 CC/Ca ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.1 NR ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 9.1 Footnote Description Footnote (a) Excludes short-term securities. Footnote (b) Ten largest investment types are presented. Additional investment types are found in Other. Footnote (c) For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated NR are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change. Footnote (d) The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors, individual investments and/or issuers. Using this approach, the investment adviser has deemed unrated U.S. Government Sponsored Agency Securities and U.S. Treasury Obligations to be of similar credit quality as investments rated AAA/Aaa. |
| C000050720 | |
| Shareholder Report [Line Items] | |
| Fund Name | BlackRock Managed Income Fund |
| Class Name | Class K Shares |
| Trading Symbol | BLDRX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about BlackRock Managed Income Fund (the “Fund”) for the period of January 1, 2024 to June 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Semi-Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports |
| Material Fund Change Notice [Text Block] | |
| Additional Information Phone Number | (800) 441-7762 |
| Additional Information Website | <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">blackrock.com/fundreports</span></span>" id="sjs-B95"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">blackrock.com/fundreports</span></span> |
| 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 K Shares $17 0.33% |
| Expenses Paid, Amount | $ 17 |
| Expense Ratio, Percent | 0.33% |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. </span>Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles." id="sjs-B99"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">Past performance is not an indication of future results. </span>Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles. |
| Average Annual Return [Table Text Block] | Fund performance Average annual total returns Average Annual Total Returns 6-Month Total Returns 1 Year 5 Years 10 Years Class K Shares ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 2.17 % 7.84 % 3.43 % 3.76 % Bloomberg U.S. Aggregate Bond Index ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ (0.71 ) 2.63 (0.23 ) 1.35 Customized Reference Benchmark ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 3.92 8.89 4.41 4.90 The Fund's returns shown prior to October 1, 2016, are the returns of the Fund when it followed a different investment objective and different investment strategies under the name BlackRock Investment Grade Bond Portfolio. The Customized Reference Benchmark is comprised of the returns of the Bloomberg U.S. Aggregate Bond Index (70%) and the S&P 500 ® |
| No Deduction of Taxes [Text Block] | Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. |
| Performance Table Market Index Changed [Text Block] | |
| Material Change Description [Text Block] | |
| Updated Performance Information Location [Text Block] | |
| AssetsNet | $ 750,243,707 |
| Holdings Count | Holding | 1,781 |
| InvestmentCompanyPortfolioTurnover | 36% |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ $750,243,707 Number of Portfolio Holdings ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 1,781 Portfolio Turnover Rate ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 36% |
| Holdings [Text Block] | Portfolio composition Credit quality allocation Investment Type Percent of Total Investments Footnote Reference Investment Companies ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 26.3 % Corporate Bonds ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 25.5 Asset-Backed Securities ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 19.4 Common Stocks ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 10.0 Floating Rate Loan Interests ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 10.0 Equity-Linked Notes ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 5.5 Non-Agency Mortgage-Backed Securities ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 1.5 U.S. Treasury Obligations ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 1.1 Foreign Agency Obligations ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.4 Foreign Government Obligations ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.2 Other Footnote Reference ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.1 Credit Rating Footnote Reference Percent of Total Investments Footnote Reference AAA/Aaa Footnote Reference ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 25.7 % AA/Aa ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 8.7 A ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 25.2 BBB/Baa ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 20.4 BB/Ba ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 4.6 B ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 5.8 CCC/Caa ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.4 CC/Ca ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 0.1 NR ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 9.1 Footnote Description Footnote (a) Excludes short-term securities. Footnote (b) Ten largest investment types are presented. Additional investment types are found in Other. Footnote (c) For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated NR are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change. Footnote (d) The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors, individual investments and/or issuers. Using this approach, the investment adviser has deemed unrated U.S. Government Sponsored Agency Securities and U.S. Treasury Obligations to be of similar credit quality as investments rated AAA/Aaa. |
| C000220895 | |
| Shareholder Report [Line Items] | |
| Fund Name | BlackRock Retirement Income 2030 Fund |
| Class Name | Institutional Shares |
| Trading Symbol | BRICX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about BlackRock Retirement Income 2030 Fund (the “Fund”) for the period of January 1, 2024 to June 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Semi-Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports |
| Material Fund Change Notice [Text Block] | |
| Additional Information Phone Number | (800) 441-7762 |
| Additional Information Website | <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">blackrock.com/fundreports</span></span>" id="sjs-B120"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">blackrock.com/fundreports</span></span> |
| 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 Institutional Shares $13 0.25% |
| Expenses Paid, Amount | $ 13 |
| Expense Ratio, Percent | 0.25% |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. </span>Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles." id="sjs-B124"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">Past performance is not an indication of future results. </span>Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles. |
| Average Annual Return [Table Text Block] | Fund performance Average annual total returns Key Fund statistics Average Annual Total Returns 6-Month Total Returns 1 Year Since inception Institutional Shares ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 3.43 % 9.63 % 3.79 % Bloomberg U.S. Aggregate Bond Index ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ (0.71 ) 2.63 (2.78 ) MSCI World Index ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 11.75 20.19 13.09 50% MSCI World Index/50% Bloomberg U.S. Aggregate Bond Index ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 5.40 11.19 5.11 Net Assets ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ $4,580,510 Number of Portfolio Holdings ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 2 Portfolio Turnover Rate ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ -% The Fund commenced operations on July 31, 2020. |
| No Deduction of Taxes [Text Block] | Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. |
| Performance Table Market Index Changed [Text Block] | |
| Material Change Description [Text Block] | |
| Updated Performance Information Location [Text Block] | |
| AssetsNet | $ 4,580,510 |
| Holdings Count | Holding | 2 |
| InvestmentCompanyPortfolioTurnover | 0% |
| Holdings [Text Block] | Portfolio composition Investment Type Percent of Affiliated Investment Companies Fixed-Income Funds ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 98.0 % Short-Term Securities ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 2.0 |
| C000220896 | |
| Shareholder Report [Line Items] | |
| Fund Name | BlackRock Retirement Income 2030 Fund |
| Class Name | Investor A Shares |
| Trading Symbol | BRIAX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about BlackRock Retirement Income 2030 Fund (the “Fund”) for the period of January 1, 2024 to June 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Semi-Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports |
| Material Fund Change Notice [Text Block] | |
| Additional Information Phone Number | (800) 441-7762 |
| Additional Information Website | <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">blackrock.com/fundreports</span></span>" id="sjs-B144"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">blackrock.com/fundreports</span></span> |
| 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 Investor A Shares $25 0.50% |
| Expenses Paid, Amount | $ 25 |
| Expense Ratio, Percent | 0.50% |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. </span>Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles." id="sjs-B148"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">Past performance is not an indication of future results. </span>Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles. |
| Average Annual Return [Table Text Block] | Fund performance Average annual total returns Key Fund statistics Average Annual Total Returns 6-Month Total Returns 1 Year Since inception Investor A Shares ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 3.30 % 9.35 % 3.53 % Investor A Shares (with sales charge) ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ (2.12 ) 3.61 2.12 Bloomberg U.S. Aggregate Bond Index ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ (0.71 ) 2.63 (2.78 ) MSCI World Index ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 11.75 20.19 13.09 50% MSCI World Index/50% Bloomberg U.S. Aggregate Bond Index ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 5.40 11.19 5.11 Net Assets ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ $4,580,510 Number of Portfolio Holdings ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 2 Portfolio Turnover Rate ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ -% The Fund commenced operations on July 31, 2020. Assuming maximum sales charges. Average annual total returns with and without sales charges reflect reductions for service fees. |
| No Deduction of Taxes [Text Block] | Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. |
| Performance Table Market Index Changed [Text Block] | |
| Material Change Description [Text Block] | |
| Updated Performance Information Location [Text Block] | |
| AssetsNet | $ 4,580,510 |
| Holdings Count | Holding | 2 |
| InvestmentCompanyPortfolioTurnover | 0% |
| Holdings [Text Block] | Portfolio composition Investment Type Percent of Affiliated Investment Companies Fixed-Income Funds ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 98.0 % Short-Term Securities ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 2.0 |
| C000220897 | |
| Shareholder Report [Line Items] | |
| Fund Name | BlackRock Retirement Income 2040 Fund |
| Class Name | Institutional Shares |
| Trading Symbol | BRIEX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about BlackRock Retirement Income 2040 Fund (the “Fund”) for the period of January 1, 2024 to June 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Semi-Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports |
| Material Fund Change Notice [Text Block] | |
| Additional Information Phone Number | (800) 441-7762 |
| Additional Information Website | <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">blackrock.com/fundreports</span></span>" id="sjs-B168"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">blackrock.com/fundreports</span></span> |
| 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 Institutional Shares $13 0.25% |
| Expenses Paid, Amount | $ 13 |
| Expense Ratio, Percent | 0.25% |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. </span>Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles." id="sjs-B172"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">Past performance is not an indication of future results. </span>Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles. |
| Average Annual Return [Table Text Block] | Fund performance Average annual total returns Key Fund statistics Average Annual Total Returns 6-Month Total Returns 1 Year Since inception Institutional Shares ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 3.44 % 9.60 % 3.85 % Bloomberg U.S. Aggregate Bond Index ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ (0.71 ) 2.63 (2.78 ) MSCI World Index ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 11.75 20.19 13.09 50% MSCI World Index/50% Bloomberg U.S. Aggregate Bond Index ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 5.40 11.19 5.11 Net Assets ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ $4,606,396 Number of Portfolio Holdings ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 2 Portfolio Turnover Rate ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ -% The Fund commenced operations on July 31, 2020. |
| No Deduction of Taxes [Text Block] | Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. |
| Performance Table Market Index Changed [Text Block] | |
| Material Change Description [Text Block] | |
| Updated Performance Information Location [Text Block] | |
| AssetsNet | $ 4,606,396 |
| Holdings Count | Holding | 2 |
| InvestmentCompanyPortfolioTurnover | 0% |
| Holdings [Text Block] | Portfolio composition Investment Type Percent of Affiliated Investment Companies Fixed-Income Funds ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 97.6 % Short-Term Securities ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 2.4 |
| C000220898 | |
| Shareholder Report [Line Items] | |
| Fund Name | BlackRock Retirement Income 2040 Fund |
| Class Name | Investor A Shares |
| Trading Symbol | BRIDX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about BlackRock Retirement Income 2040 Fund (the “Fund”) for the period of January 1, 2024 to June 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Semi-Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports |
| Material Fund Change Notice [Text Block] | |
| Additional Information Phone Number | (800) 441-7762 |
| Additional Information Website | <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">blackrock.com/fundreports</span></span>" id="sjs-B192"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">blackrock.com/fundreports</span></span> |
| 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 Investor A Shares $25 0.50% |
| Expenses Paid, Amount | $ 25 |
| Expense Ratio, Percent | 0.50% |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. </span>Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles." id="sjs-B196"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: justify;">Past performance is not an indication of future results. </span>Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles. |
| Average Annual Return [Table Text Block] | Fund performance Average annual total returns Key Fund statistics Average Annual Total Returns 6-Month Total Returns 1 Year Since inception Investor A Shares ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 3.31 % 9.33 % 3.59 % Investor A Shares (with sales charge) ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ (2.12 ) 3.59 2.18 Bloomberg U.S. Aggregate Bond Index ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ (0.71 ) 2.63 (2.78 ) MSCI World Index ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 11.75 20.19 13.09 50% MSCI World Index/50% Bloomberg U.S. Aggregate Bond Index ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 5.40 11.19 5.11 Net Assets ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ $4,606,396 Number of Portfolio Holdings ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 2 Portfolio Turnover Rate ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ -% The Fund commenced operations on July 31, 2020. Assuming maximum sales charges. Average annual total returns with and without sales charges reflect reductions for service fees. |
| No Deduction of Taxes [Text Block] | Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. |
| Performance Table Market Index Changed [Text Block] | |
| Material Change Description [Text Block] | |
| Updated Performance Information Location [Text Block] | |
| AssetsNet | $ 4,606,396 |
| Holdings Count | Holding | 2 |
| InvestmentCompanyPortfolioTurnover | 0% |
| Holdings [Text Block] | Portfolio composition Investment Type Percent of Affiliated Investment Companies Fixed-Income Funds ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 97.6 % Short-Term Securities ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 2.4 |
| Shareholder Report, Average Annual Return (Details) | 6 Months Ended | 12 Months Ended | 47 Months Ended | 60 Months Ended | 120 Months Ended |
| Jun. 30, 2024 | Jun. 30, 2024 | Jun. 30, 2024 | Jun. 30, 2024 | Jun. 30, 2024 | |
| C000050722 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (1.95%) | 3.22% | 2.28% | 2.99% | |
| C000174022 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 0.75% | 5.71% | 2.36% | 2.65% | |
| C000220896 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (2.12%) | 3.61% | 2.12% | ||
| C000220898 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (2.12%) | 3.59% | 2.18% | ||
| Without Sales Load [Member] | C000050721 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 2.26% | 7.79% | 3.40% | 3.70% | |
| Without Sales Load [Member] | C000050722 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 2.13% | 7.52% | 3.12% | 3.41% | |
| Without Sales Load [Member] | C000174022 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 1.75% | 6.71% | 2.36% | 2.65% | |
| Without Sales Load [Member] | C000050720 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 2.17% | 7.84% | 3.43% | 3.76% | |
| Without Sales Load [Member] | C000220895 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 3.43% | 9.63% | 3.79% | ||
| Without Sales Load [Member] | C000220896 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 3.30% | 9.35% | 3.53% | ||
| Without Sales Load [Member] | C000220897 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 3.44% | 9.60% | 3.85% | ||
| Without Sales Load [Member] | C000220898 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 3.31% | 9.33% | 3.59% | ||
| FR Notes - Benchmark total return 6 months w/o sales charge | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (0.71%) | ||||
| FR Notes - Benchmark total return 1 year | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 2.63% | ||||
| FR Notes - Benchmark total return 5 year | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (0.23%) | ||||
| FR Notes - Benchmark total return inception w/o sales charge | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 1.35% | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (0.71%) | ||||
| FR Notes - Benchmark total return 1 year | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 2.63% | ||||
| FR Notes - Benchmark total return 5 year | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (0.23%) | ||||
| FR Notes - Benchmark total return inception w/o sales charge | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 1.35% | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (0.71%) | ||||
| FR Notes - Benchmark total return 1 year | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 2.63% | ||||
| FR Notes - Benchmark total return 5 year | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (0.23%) | ||||
| FR Notes - Benchmark total return inception w/o sales charge | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 1.35% | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (0.71%) | ||||
| FR Notes - Benchmark total return 1 year | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 2.63% | ||||
| FR Notes - Benchmark total return 5 year | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (0.23%) | ||||
| FR Notes - Benchmark total return inception w/o sales charge | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 1.35% | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (0.71%) | ||||
| FR Notes - Benchmark total return 1 year | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 2.63% | ||||
| FR Notes - Benchmark total return inception w/o sales charge | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (2.78%) | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (0.71%) | ||||
| FR Notes - Benchmark total return 1 year | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 2.63% | ||||
| FR Notes - Benchmark total return inception w/o sales charge | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (2.78%) | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (0.71%) | ||||
| FR Notes - Benchmark total return 1 year | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 2.63% | ||||
| FR Notes - Benchmark total return inception w/o sales charge | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (2.78%) | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (0.71%) | ||||
| FR Notes - Benchmark total return 1 year | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 2.63% | ||||
| FR Notes - Benchmark total return inception w/o sales charge | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | (2.78%) | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 3.92% | ||||
| FR Notes - Benchmark total return 1 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 8.89% | ||||
| FR Notes - Benchmark total return 5 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 4.41% | ||||
| FR Notes - Benchmark total return 10 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 4.90% | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 3.92% | ||||
| FR Notes - Benchmark total return 1 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 8.89% | ||||
| FR Notes - Benchmark total return 5 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 4.41% | ||||
| FR Notes - Benchmark total return 10 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 4.90% | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 3.92% | ||||
| FR Notes - Benchmark total return 1 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 8.89% | ||||
| FR Notes - Benchmark total return 5 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 4.41% | ||||
| FR Notes - Benchmark total return 10 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 4.90% | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 3.92% | ||||
| FR Notes - Benchmark total return 1 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 8.89% | ||||
| FR Notes - Benchmark total return 5 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 4.41% | ||||
| FR Notes - Benchmark total return 10 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 4.90% | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 11.75% | ||||
| FR Notes - Benchmark total return 1 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 20.19% | ||||
| FR Notes - Benchmark total return 10 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 13.09% | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge - 3 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 5.40% | ||||
| FR Notes - Benchmark total return 1 year - 3 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 11.19% | ||||
| FR Notes - Benchmark total return 10 year - 3 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 5.11% | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 11.75% | ||||
| FR Notes - Benchmark total return 1 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 20.19% | ||||
| FR Notes - Benchmark total return 10 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 13.09% | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge - 3 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 5.40% | ||||
| FR Notes - Benchmark total return 1 year - 3 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 11.19% | ||||
| FR Notes - Benchmark total return 10 year - 3 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 5.11% | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 11.75% | ||||
| FR Notes - Benchmark total return 1 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 20.19% | ||||
| FR Notes - Benchmark total return 10 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 13.09% | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge - 3 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 5.40% | ||||
| FR Notes - Benchmark total return 1 year - 3 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 11.19% | ||||
| FR Notes - Benchmark total return 10 year - 3 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 5.11% | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 11.75% | ||||
| FR Notes - Benchmark total return 1 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 20.19% | ||||
| FR Notes - Benchmark total return 10 year - 2 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 13.09% | ||||
| FR Notes - Benchmark total return 6 months w/o sales charge - 3 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 5.40% | ||||
| FR Notes - Benchmark total return 1 year - 3 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 11.19% | ||||
| FR Notes - Benchmark total return 10 year - 3 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 5.11% |
| Shareholder Report, Holdings (Details) | Jun. 30, 2024 |
| C000050721 | AAA/Aaa | |
| Holdings [Line Items] | |
| Percent of Total Investments | 25.70% |
| C000050721 | AA/Aa | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.70% |
| C000050721 | A | |
| Holdings [Line Items] | |
| Percent of Total Investments | 25.20% |
| C000050721 | BBB/Baa | |
| Holdings [Line Items] | |
| Percent of Total Investments | 20.40% |
| C000050721 | BB/Ba | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000050721 | B | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.80% |
| C000050721 | CCC/Caa | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000050721 | CC/Ca | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.10% |
| C000050721 | NR | |
| Holdings [Line Items] | |
| Percent of Total Investments | 9.10% |
| C000050721 | Investment Companies | |
| Holdings [Line Items] | |
| Percent of Total Investments | 26.30% |
| C000050721 | Corporate Bonds | |
| Holdings [Line Items] | |
| Percent of Total Investments | 25.50% |
| C000050721 | Asset-Backed Securities | |
| Holdings [Line Items] | |
| Percent of Total Investments | 19.40% |
| C000050721 | Common Stocks | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10% |
| C000050721 | Floating Rate Loan Interests | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10% |
| C000050721 | Equity-Linked Notes | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.50% |
| C000050721 | Non-Agency Mortgage-Backed Securities | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000050721 | U.S. Treasury Obligations | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.10% |
| C000050721 | Foreign Agency Obligations | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000050721 | Foreign Government Obligations | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.20% |
| C000050721 | Other Investment Types | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.10% |
| C000050722 | AAA/Aaa | |
| Holdings [Line Items] | |
| Percent of Total Investments | 25.70% |
| C000050722 | AA/Aa | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.70% |
| C000050722 | A | |
| Holdings [Line Items] | |
| Percent of Total Investments | 25.20% |
| C000050722 | BBB/Baa | |
| Holdings [Line Items] | |
| Percent of Total Investments | 20.40% |
| C000050722 | BB/Ba | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000050722 | B | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.80% |
| C000050722 | CCC/Caa | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000050722 | CC/Ca | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.10% |
| C000050722 | NR | |
| Holdings [Line Items] | |
| Percent of Total Investments | 9.10% |
| C000050722 | Investment Companies | |
| Holdings [Line Items] | |
| Percent of Total Investments | 26.30% |
| C000050722 | Corporate Bonds | |
| Holdings [Line Items] | |
| Percent of Total Investments | 25.50% |
| C000050722 | Asset-Backed Securities | |
| Holdings [Line Items] | |
| Percent of Total Investments | 19.40% |
| C000050722 | Common Stocks | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10% |
| C000050722 | Floating Rate Loan Interests | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10% |
| C000050722 | Equity-Linked Notes | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.50% |
| C000050722 | Non-Agency Mortgage-Backed Securities | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000050722 | U.S. Treasury Obligations | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.10% |
| C000050722 | Foreign Agency Obligations | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000050722 | Foreign Government Obligations | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.20% |
| C000050722 | Other Investment Types | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.10% |
| C000174022 | AAA/Aaa | |
| Holdings [Line Items] | |
| Percent of Total Investments | 25.70% |
| C000174022 | AA/Aa | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.70% |
| C000174022 | A | |
| Holdings [Line Items] | |
| Percent of Total Investments | 25.20% |
| C000174022 | BBB/Baa | |
| Holdings [Line Items] | |
| Percent of Total Investments | 20.40% |
| C000174022 | BB/Ba | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000174022 | B | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.80% |
| C000174022 | CCC/Caa | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000174022 | CC/Ca | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.10% |
| C000174022 | NR | |
| Holdings [Line Items] | |
| Percent of Total Investments | 9.10% |
| C000174022 | Investment Companies | |
| Holdings [Line Items] | |
| Percent of Total Investments | 26.30% |
| C000174022 | Corporate Bonds | |
| Holdings [Line Items] | |
| Percent of Total Investments | 25.50% |
| C000174022 | Asset-Backed Securities | |
| Holdings [Line Items] | |
| Percent of Total Investments | 19.40% |
| C000174022 | Common Stocks | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10% |
| C000174022 | Floating Rate Loan Interests | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10% |
| C000174022 | Equity-Linked Notes | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.50% |
| C000174022 | Non-Agency Mortgage-Backed Securities | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000174022 | U.S. Treasury Obligations | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.10% |
| C000174022 | Foreign Agency Obligations | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000174022 | Foreign Government Obligations | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.20% |
| C000174022 | Other Investment Types | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.10% |
| C000050720 | AAA/Aaa | |
| Holdings [Line Items] | |
| Percent of Total Investments | 25.70% |
| C000050720 | AA/Aa | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.70% |
| C000050720 | A | |
| Holdings [Line Items] | |
| Percent of Total Investments | 25.20% |
| C000050720 | BBB/Baa | |
| Holdings [Line Items] | |
| Percent of Total Investments | 20.40% |
| C000050720 | BB/Ba | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000050720 | B | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.80% |
| C000050720 | CCC/Caa | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000050720 | CC/Ca | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.10% |
| C000050720 | NR | |
| Holdings [Line Items] | |
| Percent of Total Investments | 9.10% |
| C000050720 | Investment Companies | |
| Holdings [Line Items] | |
| Percent of Total Investments | 26.30% |
| C000050720 | Corporate Bonds | |
| Holdings [Line Items] | |
| Percent of Total Investments | 25.50% |
| C000050720 | Asset-Backed Securities | |
| Holdings [Line Items] | |
| Percent of Total Investments | 19.40% |
| C000050720 | Common Stocks | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10% |
| C000050720 | Floating Rate Loan Interests | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10% |
| C000050720 | Equity-Linked Notes | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.50% |
| C000050720 | Non-Agency Mortgage-Backed Securities | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000050720 | U.S. Treasury Obligations | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.10% |
| C000050720 | Foreign Agency Obligations | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000050720 | Foreign Government Obligations | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.20% |
| C000050720 | Other Investment Types | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.10% |
| C000220895 | Fixed-Income Funds | |
| Holdings [Line Items] | |
| Percent of Total Investments | 98% |
| C000220895 | Short-Term Securities | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000220896 | Fixed-Income Funds | |
| Holdings [Line Items] | |
| Percent of Total Investments | 98% |
| C000220896 | Short-Term Securities | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000220897 | Fixed-Income Funds | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.60% |
| C000220897 | Short-Term Securities | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000220898 | Fixed-Income Funds | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.60% |
| C000220898 | Short-Term Securities | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
