BlackRock 20/80 Target Allocation Fund, Investor A (BACPX)
Company Profile
| Form N-CSR Cover | 12 Months Ended |
| Jul. 31, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | BlackRock Funds |
| Entity Central Index Key | 0000844779 |
| Document Period End Date | Jul. 31, 2024 |
| Shareholder Report | 12 Months Ended |
| Jul. 31, 2024 USD ($) Holding | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | BlackRock Funds |
| Entity Central Index Key | 0000844779 |
| Document Period End Date | Jul. 31, 2024 |
| C000159049 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | iShares Total U.S. Stock Market Index Fund |
| Class Name | Institutional Shares |
| Trading Symbol | BITSX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about iShares Total U.S. Stock Market Index Fund (the “Fund”) for the period of August 1, 2023 to July 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports |
| Additional Information Phone Number | (800) 441‑7762 |
| Additional Information Website | blackrock.com/fundreports |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Class name Costs of a $10,000 Costs paid as a percentage of a Institutional Shares $ 0.07 % |
| Expenses Paid, Amount | $ 8 |
| Expense Ratio, Percent | 0.07% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? In the third quarter of 2023, the U.S. equity market initially rallied, supported by a falling inflation rate and resilient economic data. The U.S. Federal Reserve (the “Fed”) raised its policy rate by 25 basis points, bringing the fed funds rate to 5.25%-5.50%. However, uncertainty as to whether the Fed had reached the endpoint for the rate-hiking cycle dampened market sentiment. A slight inflation hike in August 2023 weighed on market performance. However, the Fed kept rates unchanged during their September 2023 meeting, signaling a hawkish pause that raised concerns about high rates persisting for a longer period. The U.S. equity market posted overall robust gains during the fourth quarter of 2024. The market initially dampened in October 2023 with expectations that interest rates would remain higher for longer. Optimistic inflation data later in the quarter led to hopes that interest rates had peaked, leading the market to rally. Falling consumer price index (“CPI”) data raised hopes that inflation was on course to fall back to the Fed’s 2% target. The Fed held interest rates steady for the quarter and signaled that they may have finished their series of rate hikes. This increased market expectations of rate cuts in 2024. The first quarter of 2024 saw equity markets in the United States continue to build off 2023’s momentum. Robust gains were largely driven from continued investor optimism around artificial intelligence (“AI”) development. Strong earnings reports helped buoy U.S. indices to all-time highs. Fears of a ‘valuation bubble’ began to emerge given the strong appreciation of technology stocks, but earnings reports helped mitigate these concerns. The Fed ultimately held rates steady despite expectations of a cut early in 2024. An increase in inflation in February 2024, along with strong labor market data, demonstrated continued tolerance for higher rates. Expectations of rate cuts dampened but, overall, strong earnings reports and hopes of an eventual rate cut kept market sentiment positive. Large-cap U.S. equities performed strongly during the second quarter of 2024. The S&P 500 continued to notch new all-time highs and investor optimism from better-than-expected earnings in AI-related technology stocks helped continue the rally in the large-cap market. The CPI climbed 0.3% from March 2024 and proceeded to remain flat at 0.00% from April to May 2024. Additionally, the unemployment rate increased from 3.9% in April to 4.0% in May. This data led the Fed to keep rates unchanged. Expectations of rates cuts dropped to just one cut before the end of the year. The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results. |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. |
| Line Graph [Table Text Block] | Fund performance Cumulative performance: August 13, 2015 through July 31, 2024 Initial investment of $10,000 See “Average annual total returns” for additional information on fund performance. |
| Average Annual Return [Table Text Block] | Average annual total returns 1 Year 5 Years Since Fund Institutional Shares 21.13 % 14.20 % 12.88 % Russell 3000 ® 21.07 14.23 12.91 |
| Performance Inception Date | Aug. 13, 2015 |
| 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. |
| Updated Performance Information Location [Text Block] | Visit blackrock.com |
| Net Assets | $ 3,538,267,204 |
| Holdings Count | Holding | 2,720 |
| Advisory Fees Paid, Amount | $ 287,746 |
| Investment Company Portfolio Turnover | 19% |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets $ % Number of Portfolio Holdings $ % Net Investment Advisory Fees $ % Portfolio Turnover Rate $ % |
| Holdings [Text Block] | What did the Fund invest in? (as of July 31, 2024) Sector allocation Sector (a) Percent of Information Technology 28.7 % Financials 13.6 % Health Care 11.8 % Consumer Discretionary 10.1 % Industrials 9.6 % Communication Services 8.2 % Consumer Staples 5.4 % Energy 3.8 % Real Estate 2.7 % Materials 2.6 % Other* 2.7 % Short-Term Securities 2.0 % Liabilities in Excess of Other Assets (1.2 ) Ten largest holdings Security Percent of (b) Apple, Inc. 6.0 % Microsoft Corp. 5.8 % NVIDIA Corp. 5.1 % Amazon.com, Inc. 3.2 % Meta Platforms, Inc., Class A 1.9 % Alphabet, Inc., Class A 1.9 % Alphabet, Inc., Class C 1.6 % Berkshire Hathaway, Inc., Class B 1.5 % Broadcom, Inc. 1.3 % Eli Lilly & Co. 1.3 % (a) For purposes of this report, sector sub-classifications may differ from those utilized for compliance purposes. (b) Excludes short-term securities. * Ten largest sectors are presented. Additional sectors are found in Other. |
| Largest Holdings [Text Block] | Ten largest holdings Security Percent of (b) Apple, Inc. 6.0 % Microsoft Corp. 5.8 % NVIDIA Corp. 5.1 % Amazon.com, Inc. 3.2 % Meta Platforms, Inc., Class A 1.9 % Alphabet, Inc., Class A 1.9 % Alphabet, Inc., Class C 1.6 % Berkshire Hathaway, Inc., Class B 1.5 % Broadcom, Inc. 1.3 % Eli Lilly & Co. 1.3 % |
| C000159048 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | iShares Total U.S. Stock Market Index Fund |
| Class Name | Investor A Shares |
| Trading Symbol | BASMX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about iShares Total U.S. Stock Market Index Fund (the “Fund”) for the period of August 1, 2023 to July 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports |
| Additional Information Phone Number | (800) 441‑7762 |
| Additional Information Website | blackrock.com/fundreports |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Class name Costs of a $10,000 Costs paid as a percentage of a Investor A Shares $ 0.33 % |
| Expenses Paid, Amount | $ 36 |
| Expense Ratio, Percent | 0.33% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? In the third quarter of 2023, the U.S. equity market initially rallied, supported by a falling inflation rate and resilient economic data. The U.S. Federal Reserve (the “Fed”) raised its policy rate by 25 basis points, bringing the fed funds rate to 5.25%-5.50%. However, uncertainty as to whether the Fed had reached the endpoint for the rate-hiking cycle dampened market sentiment. A slight inflation hike in August 2023 weighed on market performance. However, the Fed kept rates unchanged during their September 2023 meeting, signaling a hawkish pause that raised concerns about high rates persisting for a longer period. The U.S. equity market posted overall robust gains during the fourth quarter of 2024. The market initially dampened in October 2023 with expectations that interest rates would remain higher for longer. Optimistic inflation data later in the quarter led to hopes that interest rates had peaked, leading the market to rally. Falling consumer price index (“CPI”) data raised hopes that inflation was on course to fall back to the Fed’s 2% target. The Fed held interest rates steady for the quarter and signaled that they may have finished their series of rate hikes. This increased market expectations of rate cuts in 2024. The first quarter of 2024 saw equity markets in the United States continue to build off 2023’s momentum. Robust gains were largely driven from continued investor optimism around artificial intelligence (“AI”) development. Strong earnings reports helped buoy U.S. indices to all-time highs. Fears of a ‘valuation bubble’ began to emerge given the strong appreciation of technology stocks, but earnings reports helped mitigate these concerns. The Fed ultimately held rates steady despite expectations of a cut early in 2024. An increase in inflation in February 2024, along with strong labor market data, demonstrated continued tolerance for higher rates. Expectations of rate cuts dampened but, overall, strong earnings reports and hopes of an eventual rate cut kept market sentiment positive. Large-cap U.S. equities performed strongly during the second quarter of 2024. The S&P 500 continued to notch new all-time highs and investor optimism from better-than-expected earnings in AI-related technology stocks helped continue the rally in the large-cap market. The CPI climbed 0.3% from March 2024 and proceeded to remain flat at 0.00% from April to May 2024. Additionally, the unemployment rate increased from 3.9% in April to 4.0% in May. This data led the Fed to keep rates unchanged. Expectations of rates cuts dropped to just one cut before the end of the year. The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results. |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. |
| Line Graph [Table Text Block] | Fund performance Cumulative performance: August 13, 2015 through July 31, 2024 Initial investment of $10,000 See “Average annual total returns” for additional information on fund performance. |
| Average Annual Return [Table Text Block] | Average annual total returns 1 Year 5 Years Since Fund Investor A Shares 20.80 % 13.94 % 12.61 % Russell 3000 ® 21.07 14.23 12.91 |
| Performance Inception Date | Aug. 13, 2015 |
| 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. |
| Updated Performance Information Location [Text Block] | Visit blackrock.com |
| Net Assets | $ 3,538,267,204 |
| Holdings Count | Holding | 2,720 |
| Advisory Fees Paid, Amount | $ 287,746 |
| Investment Company Portfolio Turnover | 19% |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets $ % Number of Portfolio Holdings $ % Net Investment Advisory Fees $ % Portfolio Turnover Rate $ % |
| Holdings [Text Block] | What did the Fund invest in? (as of July 31, 2024) Sector allocation Sector (a) Percent of Information Technology 28.7 % Financials 13.6 % Health Care 11.8 % Consumer Discretionary 10.1 % Industrials 9.6 % Communication Services 8.2 % Consumer Staples 5.4 % Energy 3.8 % Real Estate 2.7 % Materials 2.6 % Other* 2.7 % Short-Term Securities 2.0 % Liabilities in Excess of Other Assets (1.2 ) Ten largest holdings Security Percent of (b) Apple, Inc. 6.0 % Microsoft Corp. 5.8 % NVIDIA Corp. 5.1 % Amazon.com, Inc. 3.2 % Meta Platforms, Inc., Class A 1.9 % Alphabet, Inc., Class A 1.9 % Alphabet, Inc., Class C 1.6 % Berkshire Hathaway, Inc., Class B 1.5 % Broadcom, Inc. 1.3 % Eli Lilly & Co. 1.3 % (a) For purposes of this report, sector sub-classifications may differ from those utilized for compliance purposes. (b) Excludes short-term securities. * Ten largest sectors are presented. Additional sectors are found in Other. |
| Largest Holdings [Text Block] | Ten largest holdings Security Percent of (b) Apple, Inc. 6.0 % Microsoft Corp. 5.8 % NVIDIA Corp. 5.1 % Amazon.com, Inc. 3.2 % Meta Platforms, Inc., Class A 1.9 % Alphabet, Inc., Class A 1.9 % Alphabet, Inc., Class C 1.6 % Berkshire Hathaway, Inc., Class B 1.5 % Broadcom, Inc. 1.3 % Eli Lilly & Co. 1.3 % |
| C000159050 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | iShares Total U.S. Stock Market Index Fund |
| Class Name | Class K Shares |
| Trading Symbol | BKTSX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about iShares Total U.S. Stock Market Index Fund (the “Fund”) for the period of August 1, 2023 to July 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports |
| Additional Information Phone Number | (800) 441‑7762 |
| Additional Information Website | blackrock.com/fundreports |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Class name Costs of a $10,000 Costs paid as a percentage of a Class K Shares $ 0.03 % |
| Expenses Paid, Amount | $ 3 |
| Expense Ratio, Percent | 0.03% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? In the third quarter of 2023, the U.S. equity market initially rallied, supported by a falling inflation rate and resilient economic data. The U.S. Federal Reserve (the “Fed”) raised its policy rate by 25 basis points, bringing the fed funds rate to 5.25%-5.50%. However, uncertainty as to whether the Fed had reached the endpoint for the rate-hiking cycle dampened market sentiment. A slight inflation hike in August 2023 weighed on market performance. However, the Fed kept rates unchanged during their September 2023 meeting, signaling a hawkish pause that raised concerns about high rates persisting for a longer period. The U.S. equity market posted overall robust gains during the fourth quarter of 2024. The market initially dampened in October 2023 with expectations that interest rates would remain higher for longer. Optimistic inflation data later in the quarter led to hopes that interest rates had peaked, leading the market to rally. Falling consumer price index (“CPI”) data raised hopes that inflation was on course to fall back to the Fed’s 2% target. The Fed held interest rates steady for the quarter and signaled that they may have finished their series of rate hikes. This increased market expectations of rate cuts in 2024. The first quarter of 2024 saw equity markets in the United States continue to build off 2023’s momentum. Robust gains were largely driven from continued investor optimism around artificial intelligence (“AI”) development. Strong earnings reports helped buoy U.S. indices to all-time highs. Fears of a ‘valuation bubble’ began to emerge given the strong appreciation of technology stocks, but earnings reports helped mitigate these concerns. The Fed ultimately held rates steady despite expectations of a cut early in 2024. An increase in inflation in February 2024, along with strong labor market data, demonstrated continued tolerance for higher rates. Expectations of rate cuts dampened but, overall, strong earnings reports and hopes of an eventual rate cut kept market sentiment positive. Large-cap U.S. equities performed strongly during the second quarter of 2024. The S&P 500 continued to notch new all-time highs and investor optimism from better-than-expected earnings in AI-related technology stocks helped continue the rally in the large-cap market. The CPI climbed 0.3% from March 2024 and proceeded to remain flat at 0.00% from April to May 2024. Additionally, the unemployment rate increased from 3.9% in April to 4.0% in May. This data led the Fed to keep rates unchanged. Expectations of rates cuts dropped to just one cut before the end of the year. The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results. |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. |
| Line Graph [Table Text Block] | Fund performance Cumulative performance: August 13, 2015 through July 31, 2024 Initial investment of $10,000 See “Average annual total returns” for additional information on fund performance. |
| Average Annual Return [Table Text Block] | Average annual total returns 1 Year 5 Years Since Fund Class K Shares 21.18 % 14.26 % 12.93 % Russell 3000 ® 21.07 14.23 12.91 |
| Performance Inception Date | Aug. 13, 2015 |
| 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. |
| Updated Performance Information Location [Text Block] | Visit blackrock.com |
| Net Assets | $ 3,538,267,204 |
| Holdings Count | Holding | 2,720 |
| Advisory Fees Paid, Amount | $ 287,746 |
| Investment Company Portfolio Turnover | 19% |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets $ % Number of Portfolio Holdings $ % Net Investment Advisory Fees $ % Portfolio Turnover Rate $ % |
| Holdings [Text Block] | What did the Fund invest in? (as of July 31, 2024) Sector allocation Sector (a) Percent of Information Technology 28.7 % Financials 13.6 % Health Care 11.8 % Consumer Discretionary 10.1 % Industrials 9.6 % Communication Services 8.2 % Consumer Staples 5.4 % Energy 3.8 % Real Estate 2.7 % Materials 2.6 % Other* 2.7 % Short-Term Securities 2.0 % Liabilities in Excess of Other Assets (1.2 ) Ten largest holdings Security Percent of (b) Apple, Inc. 6.0 % Microsoft Corp. 5.8 % NVIDIA Corp. 5.1 % Amazon.com, Inc. 3.2 % Meta Platforms, Inc., Class A 1.9 % Alphabet, Inc., Class A 1.9 % Alphabet, Inc., Class C 1.6 % Berkshire Hathaway, Inc., Class B 1.5 % Broadcom, Inc. 1.3 % Eli Lilly & Co. 1.3 % (a) For purposes of this report, sector sub-classifications may differ from those utilized for compliance purposes. (b) Excludes short-term securities. * Ten largest sectors are presented. Additional sectors are found in Other. |
| Largest Holdings [Text Block] | Ten largest holdings Security Percent of (b) Apple, Inc. 6.0 % Microsoft Corp. 5.8 % NVIDIA Corp. 5.1 % Amazon.com, Inc. 3.2 % Meta Platforms, Inc., Class A 1.9 % Alphabet, Inc., Class A 1.9 % Alphabet, Inc., Class C 1.6 % Berkshire Hathaway, Inc., Class B 1.5 % Broadcom, Inc. 1.3 % Eli Lilly & Co. 1.3 % |
| C000155940 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | iShares Russell Mid-Cap Index Fund |
| Class Name | Institutional Shares |
| Trading Symbol | BRMIX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about iShares Russell Mid-Cap Index Fund (the “Fund”) for the period of August 1, 2023 to July 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports |
| Additional Information Phone Number | (800) 441‑7762 |
| Additional Information Website | blackrock.com/fundreports |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Class name Costs of a $10,000 Costs paid as a percentage of a Institutional Shares $ 0.09 % |
| Expenses Paid, Amount | $ 10 |
| Expense Ratio, Percent | 0.09% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? In the third quarter of 2023, the U.S. equity market initially rallied, supported by a falling inflation rate and resilient economic data. The U.S. Federal Reserve (the “Fed”) raised its policy rate by 25 basis points, bringing the fed funds rate to 5.25%-5.50%. However, uncertainty as to whether the Fed had reached the endpoint for the rate-hiking cycle dampened market sentiment. A slight inflation hike in August 2023 weighed on market performance. However, the Fed kept rates unchanged during their September 2023 meeting, signaling a hawkish pause that raised concerns about high rates persisting for a longer period. The U.S. equity market posted overall robust gains during the fourth quarter of 2024. The market initially dampened in October 2023 with expectations that interest rates would remain higher for longer. Optimistic inflation data later in the quarter led to hopes that interest rates had peaked, leading the market to rally. Falling consumer price index (“CPI”) data raised hopes that inflation was on course to fall back to the Fed’s 2% target. The Fed held interest rates steady for the quarter and signaled that they may have finished their series of rate hikes. This increased market expectations of rate cuts in 2024. The first quarter of 2024 saw equity markets in the United States continue to build off 2023’s momentum. Robust gains were largely driven from continued investor optimism around artificial intelligence (“AI”) development. Strong earnings reports helped buoy U.S. indices to all-time highs. Fears of a ‘valuation bubble’ began to emerge given the strong appreciation of technology stocks, but earnings reports helped mitigate these concerns. The Fed ultimately held rates steady despite expectations of a cut early in 2024. An increase in inflation in February 2024, along with strong labor market data, demonstrated continued tolerance for higher rates. Expectations of rate cuts dampened but, overall, strong earnings reports and hopes of an eventual rate cut kept market sentiment positive. Large-cap U.S. equities performed strongly during the second quarter of 2024. The S&P 500 continued to notch new all-time highs and investor optimism from better-than-expected earnings in AI-related technology stocks helped continue the rally in the large-cap market. The CPI climbed 0.3% from March 2024 and proceeded to remain flat at 0.00% from April to May 2024. Additionally, the unemployment rate increased from 3.9% in April to 4.0% in May. This data led the Fed to keep rates unchanged. Expectations of rates cuts dropped to just one cut before the end of the year. The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results. |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. |
| Line Graph [Table Text Block] | Fund performance Cumulative performance: May 13, 2015 through July 31, 2024 Initial investment of $10,000 See “Average annual total returns” for additional information on fund performance. |
| Average Annual Return [Table Text Block] | Average annual total returns 1 Year 5 Years Since Fund Institutional Shares 13.63 % 10.12 % 9.45 % Russell 3000 ® 21.07 14.23 12.48 Russell Midcap ® 13.69 10.16 9.47 |
| Performance Inception Date | May 13, 2015 |
| 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. |
| Updated Performance Information Location [Text Block] | Visit blackrock.com |
| Net Assets | $ 1,996,331,954 |
| Holdings Count | Holding | 817 |
| Advisory Fees Paid, Amount | $ 344,702 |
| Investment Company Portfolio Turnover | 26% |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets $ % Number of Portfolio Holdings $ % Net Investment Advisory Fees $ % Portfolio Turnover Rate $ % |
| Holdings [Text Block] | What did the Fund invest in? (as of July 31, 2024) Sector allocation Sector (a) Percent of Industrials 17.1 % Financials 15.6 % Information Technology 12.4 % Consumer Discretionary 10.6 % Health Care 10.3 % Real Estate 7.7 % Materials 6.0 % Utilities 5.4 % Energy 5.3 % Consumer Staples 5.1 % Other* 4.3 % Short-Term Securities 3.6 % Liabilities in Excess of Other Assets (3.4 ) Ten largest holdings Security Percent of (b) iShares Russell Mid-Cap ETF 0.9 % Arthur J Gallagher & Co. 0.5 % Aflac, Inc. 0.5 % Palantir Technologies, Inc., Class A 0.5 % D.R. Horton, Inc. 0.5 % Hilton Worldwide Holdings, Inc. 0.5 % Williams Cos., Inc. 0.5 % United Rentals, Inc. 0.4 % Simon Property Group, Inc. 0.4 % Realty Income Corp. 0.4 % (a) For purposes of this report, sector sub-classifications may differ from those utilized for compliance purposes. (b) Excludes short-term securities. * Ten largest sectors are presented. Additional sectors are found in Other. |
| Largest Holdings [Text Block] | Ten largest holdings Security Percent of (b) iShares Russell Mid-Cap ETF 0.9 % Arthur J Gallagher & Co. 0.5 % Aflac, Inc. 0.5 % Palantir Technologies, Inc., Class A 0.5 % D.R. Horton, Inc. 0.5 % Hilton Worldwide Holdings, Inc. 0.5 % Williams Cos., Inc. 0.5 % United Rentals, Inc. 0.4 % Simon Property Group, Inc. 0.4 % Realty Income Corp. 0.4 % |
| C000163604 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | iShares Russell Mid-Cap Index Fund |
| Class Name | Investor A Shares |
| Trading Symbol | BRMAX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about iShares Russell Mid-Cap Index Fund (the “Fund”) for the period of August 1, 2023 to July 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports |
| Additional Information Phone Number | (800) 441‑7762 |
| Additional Information Website | blackrock.com/fundreports |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Class name Costs of a $10,000 Costs paid as a percentage of a Investor A Shares $ 0.36 % |
| Expenses Paid, Amount | $ 38 |
| Expense Ratio, Percent | 0.36% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? In the third quarter of 2023, the U.S. equity market initially rallied, supported by a falling inflation rate and resilient economic data. The U.S. Federal Reserve (the “Fed”) raised its policy rate by 25 basis points, bringing the fed funds rate to 5.25%-5.50%. However, uncertainty as to whether the Fed had reached the endpoint for the rate-hiking cycle dampened market sentiment. A slight inflation hike in August 2023 weighed on market performance. However, the Fed kept rates unchanged during their September 2023 meeting, signaling a hawkish pause that raised concerns about high rates persisting for a longer period. The U.S. equity market posted overall robust gains during the fourth quarter of 2024. The market initially dampened in October 2023 with expectations that interest rates would remain higher for longer. Optimistic inflation data later in the quarter led to hopes that interest rates had peaked, leading the market to rally. Falling consumer price index (“CPI”) data raised hopes that inflation was on course to fall back to the Fed’s 2% target. The Fed held interest rates steady for the quarter and signaled that they may have finished their series of rate hikes. This increased market expectations of rate cuts in 2024. The first quarter of 2024 saw equity markets in the United States continue to build off 2023’s momentum. Robust gains were largely driven from continued investor optimism around artificial intelligence (“AI”) development. Strong earnings reports helped buoy U.S. indices to all-time highs. Fears of a ‘valuation bubble’ began to emerge given the strong appreciation of technology stocks, but earnings reports helped mitigate these concerns. The Fed ultimately held rates steady despite expectations of a cut early in 2024. An increase in inflation in February 2024, along with strong labor market data, demonstrated continued tolerance for higher rates. Expectations of rate cuts dampened but, overall, strong earnings reports and hopes of an eventual rate cut kept market sentiment positive. Large-cap U.S. equities performed strongly during the second quarter of 2024. The S&P 500 continued to notch new all-time highs and investor optimism from better-than-expected earnings in AI-related technology stocks helped continue the rally in the large-cap market. The CPI climbed 0.3% from March 2024 and proceeded to remain flat at 0.00% from April to May 2024. Additionally, the unemployment rate increased from 3.9% in April to 4.0% in May. This data led the Fed to keep rates unchanged. Expectations of rates cuts dropped to just one cut before the end of the year. The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results. |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. |
| Line Graph [Table Text Block] | Fund performance Cumulative performance: May 13, 2015 through July 31, 2024 Initial investment of $10,000 See “Average annual total returns” for additional information on fund performance. |
| Average Annual Return [Table Text Block] | Average annual total returns 1 Year 5 Years Since Fund Investor A Shares 13.31 % 9.84 % 9.17 % Russell 3000 ® 21.07 14.23 12.48 Russell Midcap ® 13.69 10.16 9.47 |
| Performance Inception Date | May 13, 2015 |
| 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. |
| Updated Performance Information Location [Text Block] | Visit blackrock.com |
| Net Assets | $ 1,996,331,954 |
| Holdings Count | Holding | 817 |
| Advisory Fees Paid, Amount | $ 344,702 |
| Investment Company Portfolio Turnover | 26% |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets $ % Number of Portfolio Holdings $ % Net Investment Advisory Fees $ % Portfolio Turnover Rate $ % |
| Holdings [Text Block] | What did the Fund invest in? (as of July 31, 2024) Sector allocation Sector (a) Percent of Industrials 17.1 % Financials 15.6 % Information Technology 12.4 % Consumer Discretionary 10.6 % Health Care 10.3 % Real Estate 7.7 % Materials 6.0 % Utilities 5.4 % Energy 5.3 % Consumer Staples 5.1 % Other* 4.3 % Short-Term Securities 3.6 % Liabilities in Excess of Other Assets (3.4 ) Ten largest holdings Security Percent of (b) iShares Russell Mid-Cap ETF 0.9 % Arthur J Gallagher & Co. 0.5 % Aflac, Inc. 0.5 % Palantir Technologies, Inc., Class A 0.5 % D.R. Horton, Inc. 0.5 % Hilton Worldwide Holdings, Inc. 0.5 % Williams Cos., Inc. 0.5 % United Rentals, Inc. 0.4 % Simon Property Group, Inc. 0.4 % Realty Income Corp. 0.4 % (a) For purposes of this report, sector sub-classifications may differ from those utilized for compliance purposes. (b) Excludes short-term securities. * Ten largest sectors are presented. Additional sectors are found in Other. |
| Largest Holdings [Text Block] | Ten largest holdings Security Percent of (b) iShares Russell Mid-Cap ETF 0.9 % Arthur J Gallagher & Co. 0.5 % Aflac, Inc. 0.5 % Palantir Technologies, Inc., Class A 0.5 % D.R. Horton, Inc. 0.5 % Hilton Worldwide Holdings, Inc. 0.5 % Williams Cos., Inc. 0.5 % United Rentals, Inc. 0.4 % Simon Property Group, Inc. 0.4 % Realty Income Corp. 0.4 % |
| C000155941 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | iShares Russell Mid-Cap Index Fund |
| Class Name | Class K Shares |
| Trading Symbol | BRMKX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about iShares Russell Mid-Cap Index Fund (the “Fund”) for the period of August 1, 2023 to July 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports |
| Additional Information Phone Number | (800) 441‑7762 |
| Additional Information Website | blackrock.com/fundreports |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Class name Costs of a $10,000 Costs paid as a percentage of a Class K Shares $ 0.04 % |
| Expenses Paid, Amount | $ 4 |
| Expense Ratio, Percent | 0.04% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? In the third quarter of 2023, the U.S. equity market initially rallied, supported by a falling inflation rate and resilient economic data. The U.S. Federal Reserve (the “Fed”) raised its policy rate by 25 basis points, bringing the fed funds rate to 5.25%-5.50%. However, uncertainty as to whether the Fed had reached the endpoint for the rate-hiking cycle dampened market sentiment. A slight inflation hike in August 2023 weighed on market performance. However, the Fed kept rates unchanged during their September 2023 meeting, signaling a hawkish pause that raised concerns about high rates persisting for a longer period. The U.S. equity market posted overall robust gains during the fourth quarter of 2024. The market initially dampened in October 2023 with expectations that interest rates would remain higher for longer. Optimistic inflation data later in the quarter led to hopes that interest rates had peaked, leading the market to rally. Falling consumer price index (“CPI”) data raised hopes that inflation was on course to fall back to the Fed’s 2% target. The Fed held interest rates steady for the quarter and signaled that they may have finished their series of rate hikes. This increased market expectations of rate cuts in 2024. The first quarter of 2024 saw equity markets in the United States continue to build off 2023’s momentum. Robust gains were largely driven from continued investor optimism around artificial intelligence (“AI”) development. Strong earnings reports helped buoy U.S. indices to all-time highs. Fears of a ‘valuation bubble’ began to emerge given the strong appreciation of technology stocks, but earnings reports helped mitigate these concerns. The Fed ultimately held rates steady despite expectations of a cut early in 2024. An increase in inflation in February 2024, along with strong labor market data, demonstrated continued tolerance for higher rates. Expectations of rate cuts dampened but, overall, strong earnings reports and hopes of an eventual rate cut kept market sentiment positive. Large-cap U.S. equities performed strongly during the second quarter of 2024. The S&P 500 continued to notch new all-time highs and investor optimism from better-than-expected earnings in AI-related technology stocks helped continue the rally in the large-cap market. The CPI climbed 0.3% from March 2024 and proceeded to remain flat at 0.00% from April to May 2024. Additionally, the unemployment rate increased from 3.9% in April to 4.0% in May. This data led the Fed to keep rates unchanged. Expectations of rates cuts dropped to just one cut before the end of the year. The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results. |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. |
| Line Graph [Table Text Block] | Fund performance Cumulative performance: May 13, 2015 through July 31, 2024 Initial investment of $10,000 See “Average annual total returns” for additional information on fund performance. |
| Average Annual Return [Table Text Block] | Average annual total returns 1 Year 5 Years Since Fund Class K Shares 13.66 % 10.16 % 9.51 % Russell 3000 ® 21.07 14.23 12.48 Russell Midcap ® 13.69 10.16 9.47 |
| Performance Inception Date | May 13, 2015 |
| 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. |
| Updated Performance Information Location [Text Block] | Visit blackrock.com |
| Net Assets | $ 1,996,331,954 |
| Holdings Count | Holding | 817 |
| Advisory Fees Paid, Amount | $ 344,702 |
| Investment Company Portfolio Turnover | 26% |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets $ % Number of Portfolio Holdings $ % Net Investment Advisory Fees $ % Portfolio Turnover Rate $ % |
| Holdings [Text Block] | What did the Fund invest in? (as of July 31, 2024) Sector allocation Sector (a) Percent of Industrials 17.1 % Financials 15.6 % Information Technology 12.4 % Consumer Discretionary 10.6 % Health Care 10.3 % Real Estate 7.7 % Materials 6.0 % Utilities 5.4 % Energy 5.3 % Consumer Staples 5.1 % Other* 4.3 % Short-Term Securities 3.6 % Liabilities in Excess of Other Assets (3.4 ) Ten largest holdings Security Percent of (b) iShares Russell Mid-Cap ETF 0.9 % Arthur J Gallagher & Co. 0.5 % Aflac, Inc. 0.5 % Palantir Technologies, Inc., Class A 0.5 % D.R. Horton, Inc. 0.5 % Hilton Worldwide Holdings, Inc. 0.5 % Williams Cos., Inc. 0.5 % United Rentals, Inc. 0.4 % Simon Property Group, Inc. 0.4 % Realty Income Corp. 0.4 % (a) For purposes of this report, sector sub-classifications may differ from those utilized for compliance purposes. (b) Excludes short-term securities. * Ten largest sectors are presented. Additional sectors are found in Other. |
| Largest Holdings [Text Block] | Ten largest holdings Security Percent of (b) iShares Russell Mid-Cap ETF 0.9 % Arthur J Gallagher & Co. 0.5 % Aflac, Inc. 0.5 % Palantir Technologies, Inc., Class A 0.5 % D.R. Horton, Inc. 0.5 % Hilton Worldwide Holdings, Inc. 0.5 % Williams Cos., Inc. 0.5 % United Rentals, Inc. 0.4 % Simon Property Group, Inc. 0.4 % Realty Income Corp. 0.4 % |
| C000159052 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | iShares Russell Small/Mid-Cap Index Fund |
| Class Name | Institutional Shares |
| Trading Symbol | BSMIX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about iShares Russell Small/Mid-Cap Index Fund (the “Fund”) for the period of August 1, 2023 to July 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports |
| Additional Information Phone Number | (800) 441‑7762 |
| Additional Information Website | blackrock.com/fundreports |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Class name Costs of a $10,000 Costs paid as a percentage of a Institutional Shares $ 0.13 % |
| Expenses Paid, Amount | $ 14 |
| Expense Ratio, Percent | 0.13% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? In the third quarter of 2023, the U.S. equity market initially rallied, supported by a falling inflation rate and resilient economic data. The U.S. Federal Reserve (the “Fed”) raised its policy rate by 25 basis points, bringing the fed funds rate to 5.25%-5.50%. However, uncertainty as to whether the Fed had reached the endpoint for the rate-hiking cycle dampened market sentiment. A slight inflation hike in August 2023 weighed on market performance. However, the Fed kept rates unchanged during their September 2023 meeting, signaling a hawkish pause that raised concerns about high rates persisting for a longer period. The U.S. equity market posted overall robust gains during the fourth quarter of 2024. The market initially dampened in October 2023 with expectations that interest rates would remain higher for longer. Optimistic inflation data later in the quarter led to hopes that interest rates had peaked, leading the market to rally. Falling consumer price index (“CPI”) data raised hopes that inflation was on course to fall back to the Fed’s 2% target. The Fed held interest rates steady for the quarter and signaled that they may have finished their series of rate hikes. This increased market expectations of rate cuts in 2024. The first quarter of 2024 saw equity markets in the United States continue to build off 2023’s momentum. Robust gains were largely driven from continued investor optimism around artificial intelligence (“AI”) development. Strong earnings reports helped buoy U.S. indices to all-time highs. Fears of a ‘valuation bubble’ began to emerge given the strong appreciation of technology stocks, but earnings reports helped mitigate these concerns. The Fed ultimately held rates steady despite expectations of a cut early in 2024. An increase in inflation in February 2024, along with strong labor market data, demonstrated continued tolerance for higher rates. Expectations of rate cuts dampened but, overall, strong earnings reports and hopes of an eventual rate cut kept market sentiment positive. Large-cap U.S. equities performed strongly during the second quarter of 2024. The S&P 500 continued to notch new all-time highs and investor optimism from better-than-expected earnings in AI-related technology stocks helped continue the rally in the large-cap market. The CPI climbed 0.3% from March 2024 and proceeded to remain flat at 0.00% from April to May 2024. Additionally, the unemployment rate increased from 3.9% in April to 4.0% in May. This data led the Fed to keep rates unchanged. Expectations of rates cuts dropped to just one cut before the end of the year. The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results. |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. |
| Line Graph [Table Text Block] | Fund performance Cumulative performance: August 13, 2015 through July 31, 2024 Initial investment of $10,000 See “Average annual total returns” for additional information on fund performance. |
| Average Annual Return [Table Text Block] | Average annual total returns 1 Year 5 Years Since Fund Institutional Shares 12.90 % 9.61 % 9.30 % Russell 3000 ® 21.07 14.23 12.91 Russell 2500 ™ 13.06 9.65 9.33 |
| Performance Inception Date | Aug. 13, 2015 |
| 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. |
| Updated Performance Information Location [Text Block] | Visit blackrock.com |
| Net Assets | $ 599,823,170 |
| Holdings Count | Holding | 2,445 |
| Advisory Fees Paid, Amount | $ 89,117 |
| Investment Company Portfolio Turnover | 43% |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets $ % Number of Portfolio Holdings $ % Net Investment Advisory Fees $ % Portfolio Turnover Rate $ % |
| Holdings [Text Block] | What did the Fund invest in? (as of July 31, 2024) Sector allocation Sector (a) Percent of Industrials 18.7 % Financials 16.5 % Health Care 12.6 % Consumer Discretionary 12.3 % Information Technology 11.6 % Real Estate 6.8 % Materials 5.8 % Energy 5.4 % Consumer Staples 3.3 % Communication Services 3.0 % Other* 3.7 % Short-Term Securities 8.6 % Liabilities in Excess of Other Assets (8.3 ) Ten largest holdings Security Percent of (b) iShares Russell 2000 ETF 0.7 % iShares Russell Mid-Cap ETF 0.5 % EQT Corp. 0.3 % Lennox International, Inc. 0.3 % Textron, Inc. 0.3 % Packaging Corp. of America 0.3 % EMCOR Group, Inc. 0.3 % Reliance, Inc. 0.3 % Pure Storage, Inc., Class A 0.3 % Avery Dennison Corp. 0.3 % (a) For purposes of this report, sector sub-classifications may differ from those utilized for compliance purposes. (b) Excludes short-term securities. * Ten largest sectors are presented. Additional sectors are found in Other. |
| Largest Holdings [Text Block] | Ten largest holdings Security Percent of (b) iShares Russell 2000 ETF 0.7 % iShares Russell Mid-Cap ETF 0.5 % EQT Corp. 0.3 % Lennox International, Inc. 0.3 % Textron, Inc. 0.3 % Packaging Corp. of America 0.3 % EMCOR Group, Inc. 0.3 % Reliance, Inc. 0.3 % Pure Storage, Inc., Class A 0.3 % Avery Dennison Corp. 0.3 % |
| C000159051 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | iShares Russell Small/Mid-Cap Index Fund |
| Class Name | Investor A Shares |
| Trading Symbol | BSMAX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about iShares Russell Small/Mid-Cap Index Fund (the “Fund”) for the period of August 1, 2023 to July 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports |
| Additional Information Phone Number | (800) 441‑7762 |
| Additional Information Website | blackrock.com/fundreports |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Class name Costs of a $10,000 Costs paid as a percentage of a Investor A Shares $ 0.38 % |
| Expenses Paid, Amount | $ 40 |
| Expense Ratio, Percent | 0.38% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? In the third quarter of 2023, the U.S. equity market initially rallied, supported by a falling inflation rate and resilient economic data. The U.S. Federal Reserve (the “Fed”) raised its policy rate by 25 basis points, bringing the fed funds rate to 5.25%-5.50%. However, uncertainty as to whether the Fed had reached the endpoint for the rate-hiking cycle dampened market sentiment. A slight inflation hike in August 2023 weighed on market performance. However, the Fed kept rates unchanged during their September 2023 meeting, signaling a hawkish pause that raised concerns about high rates persisting for a longer period. The U.S. equity market posted overall robust gains during the fourth quarter of 2024. The market initially dampened in October 2023 with expectations that interest rates would remain higher for longer. Optimistic inflation data later in the quarter led to hopes that interest rates had peaked, leading the market to rally. Falling consumer price index (“CPI”) data raised hopes that inflation was on course to fall back to the Fed’s 2% target. The Fed held interest rates steady for the quarter and signaled that they may have finished their series of rate hikes. This increased market expectations of rate cuts in 2024. The first quarter of 2024 saw equity markets in the United States continue to build off 2023’s momentum. Robust gains were largely driven from continued investor optimism around artificial intelligence (“AI”) development. Strong earnings reports helped buoy U.S. indices to all-time highs. Fears of a ‘valuation bubble’ began to emerge given the strong appreciation of technology stocks, but earnings reports helped mitigate these concerns. The Fed ultimately held rates steady despite expectations of a cut early in 2024. An increase in inflation in February 2024, along with strong labor market data, demonstrated continued tolerance for higher rates. Expectations of rate cuts dampened but, overall, strong earnings reports and hopes of an eventual rate cut kept market sentiment positive. Large-cap U.S. equities performed strongly during the second quarter of 2024. The S&P 500 continued to notch new all-time highs and investor optimism from better-than-expected earnings in AI-related technology stocks helped continue the rally in the large-cap market. The CPI climbed 0.3% from March 2024 and proceeded to remain flat at 0.00% from April to May 2024. Additionally, the unemployment rate increased from 3.9% in April to 4.0% in May. This data led the Fed to keep rates unchanged. Expectations of rates cuts dropped to just one cut before the end of the year. The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results. |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. |
| Line Graph [Table Text Block] | Fund performance Cumulative performance: August 13, 2015 through July 31, 2024 Initial investment of $10,000 See “Average annual total returns” for additional information on fund performance. |
| Average Annual Return [Table Text Block] | Average annual total returns 1 Year 5 Years Since Fund Investor A Shares 12.57 % 9.34 % 9.04 % Russell 3000 ® 21.07 14.23 12.91 Russell 2500 ™ 13.06 9.65 9.33 |
| Performance Inception Date | Aug. 13, 2015 |
| 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. |
| Updated Performance Information Location [Text Block] | Visit blackrock.com |
| Net Assets | $ 599,823,170 |
| Holdings Count | Holding | 2,445 |
| Advisory Fees Paid, Amount | $ 89,117 |
| Investment Company Portfolio Turnover | 43% |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets $ % Number of Portfolio Holdings $ % Net Investment Advisory Fees $ % Portfolio Turnover Rate $ % |
| Holdings [Text Block] | What did the Fund invest in? (as of July 31, 2024) Sector allocation Sector (a) Percent of Industrials 18.7 % Financials 16.5 % Health Care 12.6 % Consumer Discretionary 12.3 % Information Technology 11.6 % Real Estate 6.8 % Materials 5.8 % Energy 5.4 % Consumer Staples 3.3 % Communication Services 3.0 % Other* 3.7 % Short-Term Securities 8.6 % Liabilities in Excess of Other Assets (8.3 ) Ten largest holdings Security Percent of (b) iShares Russell 2000 ETF 0.7 % iShares Russell Mid-Cap ETF 0.5 % EQT Corp. 0.3 % Lennox International, Inc. 0.3 % Textron, Inc. 0.3 % Packaging Corp. of America 0.3 % EMCOR Group, Inc. 0.3 % Reliance, Inc. 0.3 % Pure Storage, Inc., Class A 0.3 % Avery Dennison Corp. 0.3 % (a) For purposes of this report, sector sub-classifications may differ from those utilized for compliance purposes. (b) Excludes short-term securities. * Ten largest sectors are presented. Additional sectors are found in Other. |
| Largest Holdings [Text Block] | Ten largest holdings Security Percent of (b) iShares Russell 2000 ETF 0.7 % iShares Russell Mid-Cap ETF 0.5 % EQT Corp. 0.3 % Lennox International, Inc. 0.3 % Textron, Inc. 0.3 % Packaging Corp. of America 0.3 % EMCOR Group, Inc. 0.3 % Reliance, Inc. 0.3 % Pure Storage, Inc., Class A 0.3 % Avery Dennison Corp. 0.3 % |
| C000159053 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | iShares Russell Small/Mid-Cap Index Fund |
| Class Name | Class K Shares |
| Trading Symbol | BSMKX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about iShares Russell Small/Mid-Cap Index Fund (the “Fund”) for the period of August 1, 2023 to July 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports |
| Additional Information Phone Number | (800) 441‑7762 |
| Additional Information Website | blackrock.com/fundreports |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Class name Costs of a $10,000 Costs paid as a percentage of a Class K Shares $ 0.08 % |
| Expenses Paid, Amount | $ 9 |
| Expense Ratio, Percent | 0.08% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? In the third quarter of 2023, the U.S. equity market initially rallied, supported by a falling inflation rate and resilient economic data. The U.S. Federal Reserve (the “Fed”) raised its policy rate by 25 basis points, bringing the fed funds rate to 5.25%-5.50%. However, uncertainty as to whether the Fed had reached the endpoint for the rate-hiking cycle dampened market sentiment. A slight inflation hike in August 2023 weighed on market performance. However, the Fed kept rates unchanged during their September 2023 meeting, signaling a hawkish pause that raised concerns about high rates persisting for a longer period. The U.S. equity market posted overall robust gains during the fourth quarter of 2024. The market initially dampened in October 2023 with expectations that interest rates would remain higher for longer. Optimistic inflation data later in the quarter led to hopes that interest rates had peaked, leading the market to rally. Falling consumer price index (“CPI”) data raised hopes that inflation was on course to fall back to the Fed’s 2% target. The Fed held interest rates steady for the quarter and signaled that they may have finished their series of rate hikes. This increased market expectations of rate cuts in 2024. The first quarter of 2024 saw equity markets in the United States continue to build off 2023’s momentum. Robust gains were largely driven from continued investor optimism around artificial intelligence (“AI”) development. Strong earnings reports helped buoy U.S. indices to all-time highs. Fears of a ‘valuation bubble’ began to emerge given the strong appreciation of technology stocks, but earnings reports helped mitigate these concerns. The Fed ultimately held rates steady despite expectations of a cut early in 2024. An increase in inflation in February 2024, along with strong labor market data, demonstrated continued tolerance for higher rates. Expectations of rate cuts dampened but, overall, strong earnings reports and hopes of an eventual rate cut kept market sentiment positive. Large-cap U.S. equities performed strongly during the second quarter of 2024. The S&P 500 continued to notch new all-time highs and investor optimism from better-than-expected earnings in AI-related technology stocks helped continue the rally in the large-cap market. The CPI climbed 0.3% from March 2024 and proceeded to remain flat at 0.00% from April to May 2024. Additionally, the unemployment rate increased from 3.9% in April to 4.0% in May. This data led the Fed to keep rates unchanged. Expectations of rates cuts dropped to just one cut before the end of the year. The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results. |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. |
| Line Graph [Table Text Block] | Fund performance Cumulative performance: August 13, 2015 through July 31, 2024 Initial investment of $10,000 See “Average annual total returns” for additional information on fund performance. |
| Average Annual Return [Table Text Block] | Average annual total returns 1 Year 5 Years Since Fund Class K Shares 12.95 % 9.66 % 9.35 % Russell 3000 ® 21.07 14.23 12.91 Russell 2500 ™ 13.06 9.65 9.33 |
| Performance Inception Date | Aug. 13, 2015 |
| 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. |
| Updated Performance Information Location [Text Block] | Visit blackrock.com |
| Net Assets | $ 599,823,170 |
| Holdings Count | Holding | 2,445 |
| Advisory Fees Paid, Amount | $ 89,117 |
| Investment Company Portfolio Turnover | 43% |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets $ % Number of Portfolio Holdings $ % Net Investment Advisory Fees $ % Portfolio Turnover Rate $ % |
| Holdings [Text Block] | What did the Fund invest in? (as of July 31, 2024) Sector allocation Sector (a) Percent of Industrials 18.7 % Financials 16.5 % Health Care 12.6 % Consumer Discretionary 12.3 % Information Technology 11.6 % Real Estate 6.8 % Materials 5.8 % Energy 5.4 % Consumer Staples 3.3 % Communication Services 3.0 % Other* 3.7 % Short-Term Securities 8.6 % Liabilities in Excess of Other Assets (8.3 ) Ten largest holdings Security Percent of (b) iShares Russell 2000 ETF 0.7 % iShares Russell Mid-Cap ETF 0.5 % EQT Corp. 0.3 % Lennox International, Inc. 0.3 % Textron, Inc. 0.3 % Packaging Corp. of America 0.3 % EMCOR Group, Inc. 0.3 % Reliance, Inc. 0.3 % Pure Storage, Inc., Class A 0.3 % Avery Dennison Corp. 0.3 % (a) For purposes of this report, sector sub-classifications may differ from those utilized for compliance purposes. (b) Excludes short-term securities. * Ten largest sectors are presented. Additional sectors are found in Other. |
| Largest Holdings [Text Block] | Ten largest holdings Security Percent of (b) iShares Russell 2000 ETF 0.7 % iShares Russell Mid-Cap ETF 0.5 % EQT Corp. 0.3 % Lennox International, Inc. 0.3 % Textron, Inc. 0.3 % Packaging Corp. of America 0.3 % EMCOR Group, Inc. 0.3 % Reliance, Inc. 0.3 % Pure Storage, Inc., Class A 0.3 % Avery Dennison Corp. 0.3 % |
| Shareholder Report, Line Graph (Details) - USD ($) | 12 Months Ended | 60 Months Ended | 108 Months Ended | 111 Months Ended | |||||||||||
| Jul. 31, 2024 | Jul. 31, 2024 | Jul. 31, 2024 | Jul. 31, 2024 | Jul. 31, 2023 | Jul. 31, 2022 | Jul. 31, 2021 | Jul. 31, 2020 | Jul. 31, 2019 | Jul. 31, 2018 | Jul. 31, 2017 | Jul. 31, 2016 | Aug. 13, 2015 | Jul. 31, 2015 | May 13, 2015 | |
| C000159049 [Member] | |||||||||||||||
| Account Value [Line Items] | |||||||||||||||
| Line Graph and Table Measure Name | Institutional Shares | ||||||||||||||
| Account Value | $ 29,642 | $ 29,642 | $ 29,642 | $ 29,642 | $ 24,472 | $ 21,724 | $ 23,451 | $ 16,904 | $ 15,258 | $ 14,259 | $ 12,270 | $ 10,575 | $ 10,000 | ||
| Average Annual Return, Percent | 21.13% | 14.20% | 12.88% | ||||||||||||
| C000159048 [Member] | |||||||||||||||
| Account Value [Line Items] | |||||||||||||||
| Line Graph and Table Measure Name | Investor A Shares | ||||||||||||||
| Account Value | $ 29,014 | $ 29,014 | $ 29,014 | 29,014 | 24,017 | 21,382 | 23,126 | 16,707 | 15,111 | 14,153 | 12,215 | 10,557 | 10,000 | ||
| Average Annual Return, Percent | 20.80% | 13.94% | 12.61% | ||||||||||||
| C000159050 [Member] | |||||||||||||||
| Account Value [Line Items] | |||||||||||||||
| Line Graph and Table Measure Name | Class K Shares | ||||||||||||||
| Account Value | $ 29,753 | $ 29,753 | $ 29,753 | 29,753 | 24,553 | 21,785 | 23,506 | 16,936 | 15,279 | 14,272 | 12,276 | 10,578 | 10,000 | ||
| Average Annual Return, Percent | 21.18% | 14.26% | 12.93% | ||||||||||||
| C000155940 [Member] | |||||||||||||||
| Account Value [Line Items] | |||||||||||||||
| Line Graph and Table Measure Name | Institutional Shares | ||||||||||||||
| Account Value | $ 22,987 | $ 22,987 | $ 22,987 | $ 22,987 | 20,229 | 18,606 | 20,618 | 14,475 | 14,197 | 13,298 | 11,738 | 10,396 | $ 9,963 | $ 10,000 | |
| Average Annual Return, Percent | 13.63% | 10.12% | 9.45% | ||||||||||||
| C000163604 [Member] | |||||||||||||||
| Account Value [Line Items] | |||||||||||||||
| Line Graph and Table Measure Name | Investor A Shares | ||||||||||||||
| Account Value | $ 22,449 | $ 22,449 | 22,449 | $ 22,449 | 19,811 | 18,278 | 20,304 | 14,294 | 14,042 | 13,194 | 11,680 | 10,356 | 9,957 | 10,000 | |
| Average Annual Return, Percent | 13.31% | 9.84% | 9.17% | ||||||||||||
| C000155941 [Member] | |||||||||||||||
| Account Value [Line Items] | |||||||||||||||
| Line Graph and Table Measure Name | Class K Shares | ||||||||||||||
| Account Value | $ 23,094 | $ 23,094 | 23,094 | $ 23,094 | 20,319 | 18,684 | 20,692 | 14,521 | 14,236 | 13,329 | 11,763 | 10,407 | 9,963 | 10,000 | |
| Average Annual Return, Percent | 13.66% | 10.16% | 9.51% | ||||||||||||
| C000159052 [Member] | |||||||||||||||
| Account Value [Line Items] | |||||||||||||||
| Line Graph and Table Measure Name | Institutional Shares | ||||||||||||||
| Account Value | $ 22,204 | $ 22,204 | $ 22,204 | $ 22,204 | 19,667 | 18,206 | 20,543 | 13,797 | 14,032 | 13,952 | 11,897 | 10,344 | 10,000 | ||
| Average Annual Return, Percent | 12.90% | 9.61% | 9.30% | ||||||||||||
| C000159051 [Member] | |||||||||||||||
| Account Value [Line Items] | |||||||||||||||
| Line Graph and Table Measure Name | Investor A Shares | ||||||||||||||
| Account Value | $ 21,736 | $ 21,736 | $ 21,736 | 21,736 | 19,308 | 17,917 | 20,258 | 13,643 | 13,906 | 13,858 | 11,842 | 10,324 | 10,000 | ||
| Average Annual Return, Percent | 12.57% | 9.34% | 9.04% | ||||||||||||
| C000159053 [Member] | |||||||||||||||
| Account Value [Line Items] | |||||||||||||||
| Line Graph and Table Measure Name | Class K Shares | ||||||||||||||
| Account Value | $ 22,290 | $ 22,290 | $ 22,290 | 22,290 | 19,734 | 18,260 | 20,593 | 13,824 | 14,055 | 13,967 | 11,905 | 10,348 | 10,000 | ||
| Average Annual Return, Percent | 12.95% | 9.66% | 9.35% | ||||||||||||
| Russell 3000 Index [Member] | |||||||||||||||
| Account Value [Line Items] | |||||||||||||||
| Line Graph and Table Measure Name | Russell 3000® Index | ||||||||||||||
| Account Value | $ 29,563 | $ 29,563 | $ 29,563 | $ 29,563 | 24,417 | 21,675 | 23,395 | 16,864 | 15,203 | 14,202 | 12,201 | 10,506 | 10,000 | 10,059 | 10,000 |
| Average Annual Return, Percent | 21.07% | 14.23% | 12.91% | 12.48% | |||||||||||
| Russell Midcap Index [Member] | |||||||||||||||
| Account Value [Line Items] | |||||||||||||||
| Line Graph and Table Measure Name | Russell Midcap® Index | ||||||||||||||
| Account Value | $ 23,022 | $ 23,022 | $ 23,022 | $ 23,022 | 20,251 | 18,622 | 20,651 | 14,484 | 14,194 | 13,302 | 11,724 | 10,372 | $ 9,937 | $ 10,000 | |
| Average Annual Return, Percent | 13.69% | 10.16% | 9.47% | ||||||||||||
| Russell 2500 Index [Member] | |||||||||||||||
| Account Value [Line Items] | |||||||||||||||
| Line Graph and Table Measure Name | Russell 2500™ Index | ||||||||||||||
| Account Value | $ 22,250 | $ 22,250 | $ 22,250 | $ 22,250 | $ 19,680 | $ 18,215 | $ 20,528 | $ 13,769 | $ 14,039 | $ 13,917 | $ 11,867 | $ 10,312 | $ 10,000 | ||
| Average Annual Return, Percent | 13.06% | 9.65% | 9.33% |
| Shareholder Report, Holdings (Details) | Jul. 31, 2024 | |
| C000159049 [Member] | Apple Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6% | [1] |
| C000159049 [Member] | Microsoft Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.80% | [1] |
| C000159049 [Member] | NVIDIA Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.10% | [1] |
| C000159049 [Member] | Amazon com Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.20% | [1] |
| C000159049 [Member] | Meta Platforms Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.90% | [1] |
| C000159049 [Member] | Alphabet Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.90% | [1] |
| C000159049 [Member] | Alphabet Inc Class C [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.60% | [1] |
| C000159049 [Member] | Berkshire Hathaway Inc Class B [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.50% | [1] |
| C000159049 [Member] | Broadcom Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.30% | [1] |
| C000159049 [Member] | Eli Lilly And Co [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.30% | [1] |
| C000159049 [Member] | Energy Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.80% | [2] |
| C000159049 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 11.80% | [2] |
| C000159049 [Member] | Real Estate Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2.70% | [2] |
| C000159049 [Member] | Communications Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 8.20% | [2] |
| C000159049 [Member] | Consumer Discretionary Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.10% | [2] |
| C000159049 [Member] | Consumer Staples Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.40% | [2] |
| C000159049 [Member] | Industrial Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 9.60% | [2] |
| C000159049 [Member] | Information Technology Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 28.70% | [2] |
| C000159049 [Member] | Materials Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2.60% | [2] |
| C000159049 [Member] | Unclassified Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2.70% | [2],[3] |
| C000159049 [Member] | Financials [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 13.60% | [2] |
| C000159049 [Member] | Short Term Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2% | [2] |
| C000159049 [Member] | Liabilities in Excess of Other Assets [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (1.20%) | [2] |
| C000159048 [Member] | Apple Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6% | [4] |
| C000159048 [Member] | Microsoft Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.80% | [4] |
| C000159048 [Member] | NVIDIA Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.10% | [4] |
| C000159048 [Member] | Amazon com Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.20% | [4] |
| C000159048 [Member] | Meta Platforms Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.90% | [4] |
| C000159048 [Member] | Alphabet Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.90% | [4] |
| C000159048 [Member] | Alphabet Inc Class C [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.60% | [4] |
| C000159048 [Member] | Berkshire Hathaway Inc Class B [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.50% | [4] |
| C000159048 [Member] | Broadcom Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.30% | [4] |
| C000159048 [Member] | Eli Lilly And Co [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.30% | [4] |
| C000159048 [Member] | Energy Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.80% | [5] |
| C000159048 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 11.80% | [5] |
| C000159048 [Member] | Real Estate Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2.70% | [5] |
| C000159048 [Member] | Communications Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 8.20% | [5] |
| C000159048 [Member] | Consumer Discretionary Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.10% | [5] |
| C000159048 [Member] | Consumer Staples Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.40% | [5] |
| C000159048 [Member] | Industrial Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 9.60% | [5] |
| C000159048 [Member] | Information Technology Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 28.70% | [5] |
| C000159048 [Member] | Materials Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2.60% | [5] |
| C000159048 [Member] | Unclassified Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2.70% | [5],[6] |
| C000159048 [Member] | Financials [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 13.60% | [5] |
| C000159048 [Member] | Short Term Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2% | [5] |
| C000159048 [Member] | Liabilities in Excess of Other Assets [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (1.20%) | [5] |
| C000159050 [Member] | Apple Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6% | [7] |
| C000159050 [Member] | Microsoft Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.80% | [7] |
| C000159050 [Member] | NVIDIA Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.10% | [7] |
| C000159050 [Member] | Amazon com Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.20% | [7] |
| C000159050 [Member] | Meta Platforms Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.90% | [7] |
| C000159050 [Member] | Alphabet Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.90% | [7] |
| C000159050 [Member] | Alphabet Inc Class C [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.60% | [7] |
| C000159050 [Member] | Berkshire Hathaway Inc Class B [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.50% | [7] |
| C000159050 [Member] | Broadcom Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.30% | [7] |
| C000159050 [Member] | Eli Lilly And Co [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.30% | [7] |
| C000159050 [Member] | Energy Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.80% | [8] |
| C000159050 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 11.80% | [8] |
| C000159050 [Member] | Real Estate Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2.70% | [8] |
| C000159050 [Member] | Communications Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 8.20% | [8] |
| C000159050 [Member] | Consumer Discretionary Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.10% | [8] |
| C000159050 [Member] | Consumer Staples Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.40% | [8] |
| C000159050 [Member] | Industrial Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 9.60% | [8] |
| C000159050 [Member] | Information Technology Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 28.70% | [8] |
| C000159050 [Member] | Materials Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2.60% | [8] |
| C000159050 [Member] | Unclassified Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2.70% | [8],[9] |
| C000159050 [Member] | Financials [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 13.60% | [8] |
| C000159050 [Member] | Short Term Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2% | [8] |
| C000159050 [Member] | Liabilities in Excess of Other Assets [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (1.20%) | [8] |
| C000155940 [Member] | iShares Russell Mid Cap ETF [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.90% | [10] |
| C000155940 [Member] | Arthur J Gallagher And Co [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [10] |
| C000155940 [Member] | Aflac Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [10] |
| C000155940 [Member] | Palantir Technologies Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [10] |
| C000155940 [Member] | D R Horton Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [10] |
| C000155940 [Member] | Hilton Worldwide Holdings Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [10] |
| C000155940 [Member] | Williams Cos Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [10] |
| C000155940 [Member] | United Rentals Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.40% | [10] |
| C000155940 [Member] | Simon Property Group Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.40% | [10] |
| C000155940 [Member] | Realty Income Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.40% | [10] |
| C000155940 [Member] | Energy Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.30% | [11] |
| C000155940 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.30% | [11] |
| C000155940 [Member] | Real Estate Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 7.70% | [11] |
| C000155940 [Member] | Consumer Discretionary Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.60% | [11] |
| C000155940 [Member] | Consumer Staples Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.10% | [11] |
| C000155940 [Member] | Industrial Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 17.10% | [11] |
| C000155940 [Member] | Information Technology Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.40% | [11] |
| C000155940 [Member] | Materials Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6% | [11] |
| C000155940 [Member] | Unclassified Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.30% | [11],[12] |
| C000155940 [Member] | Financials [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 15.60% | [11] |
| C000155940 [Member] | Utilities Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.40% | [11] |
| C000155940 [Member] | Short Term Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.60% | [11] |
| C000155940 [Member] | Liabilities in Excess of Other Assets [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (3.40%) | [11] |
| C000163604 [Member] | iShares Russell Mid Cap ETF [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.90% | [13] |
| C000163604 [Member] | Arthur J Gallagher And Co [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [13] |
| C000163604 [Member] | Aflac Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [13] |
| C000163604 [Member] | Palantir Technologies Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [13] |
| C000163604 [Member] | D R Horton Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [13] |
| C000163604 [Member] | Hilton Worldwide Holdings Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [13] |
| C000163604 [Member] | Williams Cos Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [13] |
| C000163604 [Member] | United Rentals Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.40% | [13] |
| C000163604 [Member] | Simon Property Group Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.40% | [13] |
| C000163604 [Member] | Realty Income Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.40% | [13] |
| C000163604 [Member] | Energy Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.30% | [14] |
| C000163604 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.30% | [14] |
| C000163604 [Member] | Real Estate Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 7.70% | [14] |
| C000163604 [Member] | Consumer Discretionary Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.60% | [14] |
| C000163604 [Member] | Consumer Staples Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.10% | [14] |
| C000163604 [Member] | Industrial Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 17.10% | [14] |
| C000163604 [Member] | Information Technology Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.40% | [14] |
| C000163604 [Member] | Materials Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6% | [14] |
| C000163604 [Member] | Unclassified Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.30% | [14],[15] |
| C000163604 [Member] | Financials [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 15.60% | [14] |
| C000163604 [Member] | Utilities Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.40% | [14] |
| C000163604 [Member] | Short Term Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.60% | [14] |
| C000163604 [Member] | Liabilities in Excess of Other Assets [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (3.40%) | [14] |
| C000155941 [Member] | iShares Russell Mid Cap ETF [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.90% | [16] |
| C000155941 [Member] | Arthur J Gallagher And Co [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [16] |
| C000155941 [Member] | Aflac Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [16] |
| C000155941 [Member] | Palantir Technologies Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [16] |
| C000155941 [Member] | D R Horton Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [16] |
| C000155941 [Member] | Hilton Worldwide Holdings Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [16] |
| C000155941 [Member] | Williams Cos Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [16] |
| C000155941 [Member] | United Rentals Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.40% | [16] |
| C000155941 [Member] | Simon Property Group Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.40% | [16] |
| C000155941 [Member] | Realty Income Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.40% | [16] |
| C000155941 [Member] | Energy Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.30% | [17] |
| C000155941 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.30% | [17] |
| C000155941 [Member] | Real Estate Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 7.70% | [17] |
| C000155941 [Member] | Consumer Discretionary Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.60% | [17] |
| C000155941 [Member] | Consumer Staples Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.10% | [17] |
| C000155941 [Member] | Industrial Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 17.10% | [17] |
| C000155941 [Member] | Information Technology Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.40% | [17] |
| C000155941 [Member] | Materials Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6% | [17] |
| C000155941 [Member] | Unclassified Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.30% | [17],[18] |
| C000155941 [Member] | Financials [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 15.60% | [17] |
| C000155941 [Member] | Utilities Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.40% | [17] |
| C000155941 [Member] | Short Term Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.60% | [17] |
| C000155941 [Member] | Liabilities in Excess of Other Assets [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (3.40%) | [17] |
| C000159052 [Member] | iShares Russell Mid Cap ETF [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [19] |
| C000159052 [Member] | iShares Russell 2000 ETF [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.70% | [19] |
| C000159052 [Member] | EQT Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [19] |
| C000159052 [Member] | Lennox International Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [19] |
| C000159052 [Member] | Textron Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [19] |
| C000159052 [Member] | Packaging Corp of America [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [19] |
| C000159052 [Member] | EMCOR Group Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [19] |
| C000159052 [Member] | Reliance Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [19] |
| C000159052 [Member] | Pure Storage Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [19] |
| C000159052 [Member] | Avery Dennison Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [19] |
| C000159052 [Member] | Energy Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.40% | [20] |
| C000159052 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.60% | [20] |
| C000159052 [Member] | Real Estate Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.80% | [20] |
| C000159052 [Member] | Communications Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3% | [20] |
| C000159052 [Member] | Consumer Discretionary Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.30% | [20] |
| C000159052 [Member] | Consumer Staples Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.30% | [20] |
| C000159052 [Member] | Industrial Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 18.70% | [20] |
| C000159052 [Member] | Information Technology Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 11.60% | [20] |
| C000159052 [Member] | Materials Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.80% | [20] |
| C000159052 [Member] | Unclassified Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.70% | [20],[21] |
| C000159052 [Member] | Financials [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 16.50% | [20] |
| C000159052 [Member] | Short Term Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 8.60% | [20] |
| C000159052 [Member] | Liabilities in Excess of Other Assets [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (8.30%) | [20] |
| C000159051 [Member] | iShares Russell Mid Cap ETF [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [22] |
| C000159051 [Member] | iShares Russell 2000 ETF [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.70% | [22] |
| C000159051 [Member] | EQT Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [22] |
| C000159051 [Member] | Lennox International Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [22] |
| C000159051 [Member] | Textron Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [22] |
| C000159051 [Member] | Packaging Corp of America [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [22] |
| C000159051 [Member] | EMCOR Group Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [22] |
| C000159051 [Member] | Reliance Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [22] |
| C000159051 [Member] | Pure Storage Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [22] |
| C000159051 [Member] | Avery Dennison Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [22] |
| C000159051 [Member] | Energy Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.40% | [23] |
| C000159051 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.60% | [23] |
| C000159051 [Member] | Real Estate Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.80% | [23] |
| C000159051 [Member] | Communications Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3% | [23] |
| C000159051 [Member] | Consumer Discretionary Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.30% | [23] |
| C000159051 [Member] | Consumer Staples Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.30% | [23] |
| C000159051 [Member] | Industrial Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 18.70% | [23] |
| C000159051 [Member] | Information Technology Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 11.60% | [23] |
| C000159051 [Member] | Materials Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.80% | [23] |
| C000159051 [Member] | Unclassified Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.70% | [23],[24] |
| C000159051 [Member] | Financials [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 16.50% | [23] |
| C000159051 [Member] | Short Term Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 8.60% | [23] |
| C000159051 [Member] | Liabilities in Excess of Other Assets [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (8.30%) | [23] |
| C000159053 [Member] | iShares Russell Mid Cap ETF [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | [25] |
| C000159053 [Member] | iShares Russell 2000 ETF [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.70% | [25] |
| C000159053 [Member] | EQT Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [25] |
| C000159053 [Member] | Lennox International Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [25] |
| C000159053 [Member] | Textron Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [25] |
| C000159053 [Member] | Packaging Corp of America [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [25] |
| C000159053 [Member] | EMCOR Group Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [25] |
| C000159053 [Member] | Reliance Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [25] |
| C000159053 [Member] | Pure Storage Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [25] |
| C000159053 [Member] | Avery Dennison Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | [25] |
| C000159053 [Member] | Energy Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.40% | [26] |
| C000159053 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.60% | [26] |
| C000159053 [Member] | Real Estate Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.80% | [26] |
| C000159053 [Member] | Communications Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3% | [26] |
| C000159053 [Member] | Consumer Discretionary Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.30% | [26] |
| C000159053 [Member] | Consumer Staples Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.30% | [26] |
| C000159053 [Member] | Industrial Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 18.70% | [26] |
| C000159053 [Member] | Information Technology Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 11.60% | [26] |
| C000159053 [Member] | Materials Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.80% | [26] |
| C000159053 [Member] | Unclassified Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.70% | [26],[27] |
| C000159053 [Member] | Financials [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 16.50% | [26] |
| C000159053 [Member] | Short Term Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 8.60% | [26] |
| C000159053 [Member] | Liabilities in Excess of Other Assets [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (8.30%) | [26] |
| [1]Excludes short-term securities.[2]For purposes of this report, sector sub-classifications may differ from those utilized for compliance purposes.[3]Ten largest sectors are presented. Additional sectors are found in Other.[4]Excludes short-term securities.[5]For purposes of this report, sector sub-classifications may differ from those utilized for compliance purposes.[6]Ten largest sectors are presented. Additional sectors are found in Other.[7]Excludes short-term securities.[8]For purposes of this report, sector sub-classifications may differ from those utilized for compliance purposes.[9]Ten largest sectors are presented. Additional sectors are found in Other.[10]Excludes short-term securities.[11]For purposes of this report, sector sub-classifications may differ from those utilized for compliance purposes.[12]Ten largest sectors are presented. Additional sectors are found in Other.[13]Excludes short-term securities.[14]For purposes of this report, sector sub-classifications may differ from those utilized for compliance purposes.[15]Ten largest sectors are presented. Additional sectors are found in Other.[16]Excludes short-term securities.[17]For purposes of this report, sector sub-classifications may differ from those utilized for compliance purposes.[18]Ten largest sectors are presented. Additional sectors are found in Other.[19]Excludes short-term securities.[20]For purposes of this report, sector sub-classifications may differ from those utilized for compliance purposes.[21]Ten largest sectors are presented. Additional sectors are found in Other.[22]Excludes short-term securities.[23]For purposes of this report, sector sub-classifications may differ from those utilized for compliance purposes.[24]Ten largest sectors are presented. Additional sectors are found in Other.[25]Excludes short-term securities.[26]For purposes of this report, sector sub-classifications may differ from those utilized for compliance purposes.[27]Ten largest sectors are presented. Additional sectors are found in Other. | ||