| Form N-CSR Cover | 12 Months Ended |
| May 31, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | BlackRock Series, Inc. |
| Entity Central Index Key | 0001062806 |
| Document Period End Date | May 31, 2024 |
| Shareholder Report | 12 Months Ended |
| May 31, 2024 USD ($) Holding | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | BlackRock Series, Inc. |
| Entity Central Index Key | 0001062806 |
| Document Period End Date | May 31, 2024 |
| C000198221 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | BlackRock International Fund |
| Class Name | Class K Shares |
| Trading Symbol | MKILX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about BlackRock International Fund (the “Fund”) for the period of June 1, 2023 to May 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 $ 0.61 % |
| Expenses Paid, Amount | $ 66 |
| Expense Ratio, Percent | 0.61% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? International equities broadly moved higher as the period progressed, resulting in significant positive returns across most market segments. Major overseas economies returned to positive growth, supporting the corporate earnings outlook. Signs of easing inflation led to expectations that leading central banks were poised to begin reducing interest rates. What contributed to performance? Positive contributions to performance, relative to the benchmark (MSCI ACWI ex USA Index) were led by stock selection within the financials, communication services, and energy sectors. At the individual stock level, Recruit Holdings Co., Ltd., a Japanese human resources and technology company with flagship job search engines Indeed and Glassdoor, contributed. Shares of Recruit have been supported by a favorable macroeconomic backdrop. Intesa Sanpaolo S.p.A. is an Italian international banking group which outperformed on the back of higher interest rates and a steady macro backdrop. Danish pharmaceutical company Novo Nordisk A/S continued its strong performance, announcing at its March 2024 capital markets day positive early data on a new oral drug for treatment of obesity. What detracted from performance? The largest detractors from performance included stock selection within consumer discretionary, healthcare, and materials. At the individual stock level, Swiss multinational manufacturer Lonza Group AG experienced the unexpected departure of its CEO in September of 2023 and issued weaker guidance at its October 2023 capital markets day, reflecting a larger-than-expected Covid 19 demand overhang. The Fund exited the position. Management of Sony Group Corp. provided conservative commentary on near-term gaming segment margins given higher hardware and marketing costs for its Playstation 5 console. Yum China Holdings, Inc., the parent company of KFC and Pizza Hut and a major player in the Chinese fast-food market, underperformed along with broader negative sentiment and weakness in the Chinese market. 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: June 1, 2014 through May 31, 2024 Initial 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 10 Years Class K Shares 15.52 % 8.01 % 4.71 % MSCI ACWI ex USA Index 16.74 % 6.81 % 4.03 % |
| 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 | $ 1,725,206,070 |
| Holdings Count | Holding | 33 |
| Advisory Fees Paid, Amount | $ 9,808,933 |
| Investment Company Portfolio Turnover | 86% |
| 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 May 31, 2024) Geographic allocation Country Percent of Japan 15.4 % Germany 12.5 % United States 12.1 % United Kingdom 10.3 % Canada 10.3 % France 9.0 % Netherlands 6.3 % Denmark 6.1 % China 3.9 % Italy 3.8 % Other 8.0 % Short-Term Securities 2.1 % Other Assets Less Liabilities 0.2 % Ten largest holdings Security (a) Percent of Novo Nordisk A/S, Class B 6.1 % Beiersdorf AG 5.4 % Sony Group Corp. 5.3 % Recruit Holdings Co. Ltd. 4.8 % Canadian National Railway Co. 4.8 % ASML Holding NV 4.7 % Mastercard, Inc., Class A 4.5 % Deutsche Telekom AG, Registered Shares 4.0 % Canadian Pacific Kansas City Ltd. 4.0 % Tencent Holdings Ltd. 3.9 % (a) Excludes short-term securities. |
| Largest Holdings [Text Block] | Ten largest holdings Security (a) Percent of Novo Nordisk A/S, Class B 6.1 % Beiersdorf AG 5.4 % Sony Group Corp. 5.3 % Recruit Holdings Co. Ltd. 4.8 % Canadian National Railway Co. 4.8 % ASML Holding NV 4.7 % Mastercard, Inc., Class A 4.5 % Deutsche Telekom AG, Registered Shares 4.0 % Canadian Pacific Kansas City Ltd. 4.0 % Tencent Holdings Ltd. 3.9 % (a) Excludes short-term securities. |
| C000005984 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | BlackRock International Fund |
| Class Name | Institutional Shares |
| Trading Symbol | MAILX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about BlackRock International Fund (the “Fund”) for the period of June 1, 2023 to May 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 $ 0.66 % |
| Expenses Paid, Amount | $ 71 |
| Expense Ratio, Percent | 0.66% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? International equities broadly moved higher as the period progressed, resulting in significant positive returns across most market segments. Major overseas economies returned to positive growth, supporting the corporate earnings outlook. Signs of easing inflation led to expectations that leading central banks were poised to begin reducing interest rates. What contributed to performance? Positive contributions to performance, relative to the benchmark (MSCI ACWI ex USA Index) were led by stock selection within the financials, communication services, and energy sectors. At the individual stock level, Recruit Holdings Co., Ltd., a Japanese human resources and technology company with flagship job search engines Indeed and Glassdoor, contributed. Shares of Recruit have been supported by a favorable macroeconomic backdrop. Intesa Sanpaolo S.p.A. is an Italian international banking group which outperformed on the back of higher interest rates and a steady macro backdrop. Danish pharmaceutical company Novo Nordisk A/S continued its strong performance, announcing at its March 2024 capital markets day positive early data on a new oral drug for treatment of obesity. What detracted from performance? The largest detractors from performance included stock selection within consumer discretionary, healthcare, and materials. At the individual stock level, Swiss multinational manufacturer Lonza Group AG experienced the unexpected departure of its CEO in September of 2023 and issued weaker guidance at its October 2023 capital markets day, reflecting a larger-than-expected Covid 19 demand overhang. The Fund exited the position. Management of Sony Group Corp. provided conservative commentary on near-term gaming segment margins given higher hardware and marketing costs for its Playstation 5 console. Yum China Holdings, Inc., the parent company of KFC and Pizza Hut and a major player in the Chinese fast-food market, underperformed along with broader negative sentiment and weakness in the Chinese market. 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: June 1, 2014 through May 31, 2024 Initial 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 10 Years Institutional Shares 15.47 % 7.95 % 4.67 % MSCI ACWI ex USA Index 16.74 % 6.81 % 4.03 % |
| 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 | $ 1,725,206,070 |
| Holdings Count | Holding | 33 |
| Advisory Fees Paid, Amount | $ 9,808,933 |
| Investment Company Portfolio Turnover | 86% |
| 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 May 31, 2024) Geographic allocation Country Percent of Japan 15.4 % Germany 12.5 % United States 12.1 % United Kingdom 10.3 % Canada 10.3 % France 9.0 % Netherlands 6.3 % Denmark 6.1 % China 3.9 % Italy 3.8 % Other 8.0 % Short-Term Securities 2.1 % Other Assets Less Liabilities 0.2 % Ten largest holdings Security (a) Percent of Novo Nordisk A/S, Class B 6.1 % Beiersdorf AG 5.4 % Sony Group Corp. 5.3 % Recruit Holdings Co. Ltd. 4.8 % Canadian National Railway Co. 4.8 % ASML Holding NV 4.7 % Mastercard, Inc., Class A 4.5 % Deutsche Telekom AG, Registered Shares 4.0 % Canadian Pacific Kansas City Ltd. 4.0 % Tencent Holdings Ltd. 3.9 % (a) Excludes short-term securities. |
| Largest Holdings [Text Block] | Ten largest holdings Security (a) Percent of Novo Nordisk A/S, Class B 6.1 % Beiersdorf AG 5.4 % Sony Group Corp. 5.3 % Recruit Holdings Co. Ltd. 4.8 % Canadian National Railway Co. 4.8 % ASML Holding NV 4.7 % Mastercard, Inc., Class A 4.5 % Deutsche Telekom AG, Registered Shares 4.0 % Canadian Pacific Kansas City Ltd. 4.0 % Tencent Holdings Ltd. 3.9 % (a) Excludes short-term securities. |
| C000005983 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | BlackRock International Fund |
| Class Name | Investor C Shares |
| Trading Symbol | MCILX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about BlackRock International Fund (the “Fund”) for the period of June 1, 2023 to May 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 C Shares $ 1.66 % |
| Expenses Paid, Amount | $ 178 |
| Expense Ratio, Percent | 1.66% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? International equities broadly moved higher as the period progressed, resulting in significant positive returns across most market segments. Major overseas economies returned to positive growth, supporting the corporate earnings outlook. Signs of easing inflation led to expectations that leading central banks were poised to begin reducing interest rates. What contributed to performance? Positive contributions to performance, relative to the benchmark (MSCI ACWI ex USA Index) were led by stock selection within the financials, communication services, and energy sectors. At the individual stock level, Recruit Holdings Co., Ltd., a Japanese human resources and technology company with flagship job search engines Indeed and Glassdoor, contributed. Shares of Recruit have been supported by a favorable macroeconomic backdrop. Intesa Sanpaolo S.p.A. is an Italian international banking group which outperformed on the back of higher interest rates and a steady macro backdrop. Danish pharmaceutical company Novo Nordisk A/S continued its strong performance, announcing at its March 2024 capital markets day positive early data on a new oral drug for treatment of obesity. What detracted from performance? The largest detractors from performance included stock selection within consumer discretionary, healthcare, and materials. At the individual stock level, Swiss multinational manufacturer Lonza Group AG experienced the unexpected departure of its CEO in September of 2023 and issued weaker guidance at its October 2023 capital markets day, reflecting a larger-than-expected Covid 19 demand overhang. The Fund exited the position. Management of Sony Group Corp. provided conservative commentary on near-term gaming segment margins given higher hardware and marketing costs for its Playstation 5 console. Yum China Holdings, Inc., the parent company of KFC and Pizza Hut and a major player in the Chinese fast-food market, underperformed along with broader negative sentiment and weakness in the Chinese market. 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: June 1, 2014 through May 31, 2024 Initial 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 10 Years Investor C Shares 14.34 % 6.88 % 3.65 % Investor C Shares (with sales charge) 13.34 % 6.88 % 3.65 % MSCI ACWI ex USA Index 16.74 % 6.81 % 4.03 % |
| 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 | $ 1,725,206,070 |
| Holdings Count | Holding | 33 |
| Advisory Fees Paid, Amount | $ 9,808,933 |
| Investment Company Portfolio Turnover | 86% |
| 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 May 31, 2024) Geographic allocation Country Percent of Japan 15.4 % Germany 12.5 % United States 12.1 % United Kingdom 10.3 % Canada 10.3 % France 9.0 % Netherlands 6.3 % Denmark 6.1 % China 3.9 % Italy 3.8 % Other 8.0 % Short-Term Securities 2.1 % Other Assets Less Liabilities 0.2 % Ten largest holdings Security (a) Percent of Novo Nordisk A/S, Class B 6.1 % Beiersdorf AG 5.4 % Sony Group Corp. 5.3 % Recruit Holdings Co. Ltd. 4.8 % Canadian National Railway Co. 4.8 % ASML Holding NV 4.7 % Mastercard, Inc., Class A 4.5 % Deutsche Telekom AG, Registered Shares 4.0 % Canadian Pacific Kansas City Ltd. 4.0 % Tencent Holdings Ltd. 3.9 % (a) Excludes short-term securities. |
| Largest Holdings [Text Block] | Ten largest holdings Security (a) Percent of Novo Nordisk A/S, Class B 6.1 % Beiersdorf AG 5.4 % Sony Group Corp. 5.3 % Recruit Holdings Co. Ltd. 4.8 % Canadian National Railway Co. 4.8 % ASML Holding NV 4.7 % Mastercard, Inc., Class A 4.5 % Deutsche Telekom AG, Registered Shares 4.0 % Canadian Pacific Kansas City Ltd. 4.0 % Tencent Holdings Ltd. 3.9 % (a) Excludes short-term securities. |
| C000101856 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | BlackRock International Fund |
| Class Name | Class R Shares |
| Trading Symbol | BIFRX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about BlackRock International Fund (the “Fund”) for the period of June 1, 2023 to May 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 R Shares $ 1.16 % |
| Expenses Paid, Amount | $ 125 |
| Expense Ratio, Percent | 1.16% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? International equities broadly moved higher as the period progressed, resulting in significant positive returns across most market segments. Major overseas economies returned to positive growth, supporting the corporate earnings outlook. Signs of easing inflation led to expectations that leading central banks were poised to begin reducing interest rates. What contributed to performance? Positive contributions to performance, relative to the benchmark (MSCI ACWI ex USA Index) were led by stock selection within the financials, communication services, and energy sectors. At the individual stock level, Recruit Holdings Co., Ltd., a Japanese human resources and technology company with flagship job search engines Indeed and Glassdoor, contributed. Shares of Recruit have been supported by a favorable macroeconomic backdrop. Intesa Sanpaolo S.p.A. is an Italian international banking group which outperformed on the back of higher interest rates and a steady macro backdrop. Danish pharmaceutical company Novo Nordisk A/S continued its strong performance, announcing at its March 2024 capital markets day positive early data on a new oral drug for treatment of obesity. What detracted from performance? The largest detractors from performance included stock selection within consumer discretionary, healthcare, and materials. At the individual stock level, Swiss multinational manufacturer Lonza Group AG experienced the unexpected departure of its CEO in September of 2023 and issued weaker guidance at its October 2023 capital markets day, reflecting a larger-than-expected Covid 19 demand overhang. The Fund exited the position. Management of Sony Group Corp. provided conservative commentary on near-term gaming segment margins given higher hardware and marketing costs for its Playstation 5 console. Yum China Holdings, Inc., the parent company of KFC and Pizza Hut and a major player in the Chinese fast-food market, underperformed along with broader negative sentiment and weakness in the Chinese market. 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: June 1, 2014 through May 31, 2024 Initial 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 10 Years Class R Shares 14.83 % 7.41 % 4.08 % MSCI ACWI ex USA Index 16.74 % 6.81 % 4.03 % |
| 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 | $ 1,725,206,070 |
| Holdings Count | Holding | 33 |
| Advisory Fees Paid, Amount | $ 9,808,933 |
| Investment Company Portfolio Turnover | 86% |
| 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 May 31, 2024) Geographic allocation Country Percent of Japan 15.4 % Germany 12.5 % United States 12.1 % United Kingdom 10.3 % Canada 10.3 % France 9.0 % Netherlands 6.3 % Denmark 6.1 % China 3.9 % Italy 3.8 % Other 8.0 % Short-Term Securities 2.1 % Other Assets Less Liabilities 0.2 % Security (a) Percent of Novo Nordisk A/S, Class B 6.1 % Beiersdorf AG 5.4 % Sony Group Corp. 5.3 % Recruit Holdings Co. Ltd. 4.8 % Canadian National Railway Co. 4.8 % ASML Holding NV 4.7 % Mastercard, Inc., Class A 4.5 % Deutsche Telekom AG, Registered Shares 4.0 % Canadian Pacific Kansas City Ltd. 4.0 % Tencent Holdings Ltd. 3.9 % (a) Excludes short-term securities. |
| Largest Holdings [Text Block] | Ten largest holdings Security (a) Percent of Novo Nordisk A/S, Class B 6.1 % Beiersdorf AG 5.4 % Sony Group Corp. 5.3 % Recruit Holdings Co. Ltd. 4.8 % Canadian National Railway Co. 4.8 % ASML Holding NV 4.7 % Mastercard, Inc., Class A 4.5 % Deutsche Telekom AG, Registered Shares 4.0 % Canadian Pacific Kansas City Ltd. 4.0 % Tencent Holdings Ltd. 3.9 % (a) Excludes short-term securities. |
| C000005981 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | BlackRock International Fund |
| Class Name | Investor A Shares |
| Trading Symbol | MDILX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about BlackRock International Fund (the “Fund”) for the period of June 1, 2023 to May 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 $ 0.91 % |
| Expenses Paid, Amount | $ 98 |
| Expense Ratio, Percent | 0.91% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year? International equities broadly moved higher as the period progressed, resulting in significant positive returns across most market segments. Major overseas economies returned to positive growth, supporting the corporate earnings outlook. Signs of easing inflation led to expectations that leading central banks were poised to begin reducing interest rates. What contributed to performance? Positive contributions to performance, relative to the benchmark (MSCI ACWI ex USA Index) were led by stock selection within the financials, communication services, and energy sectors. At the individual stock level, Recruit Holdings Co., Ltd., a Japanese human resources and technology company with flagship job search engines Indeed and Glassdoor, contributed. Shares of Recruit have been supported by a favorable macroeconomic backdrop. Intesa Sanpaolo S.p.A. is an Italian international banking group which outperformed on the back of higher interest rates and a steady macro backdrop. Danish pharmaceutical company Novo Nordisk A/S continued its strong performance, announcing at its March 2024 capital markets day positive early data on a new oral drug for treatment of obesity. What detracted from performance? The largest detractors from performance included stock selection within consumer discretionary, healthcare, and materials. At the individual stock level, Swiss multinational manufacturer Lonza Group AG experienced the unexpected departure of its CEO in September of 2023 and issued weaker guidance at its October 2023 capital markets day, reflecting a larger-than-expected Covid 19 demand overhang. The Fund exited the position. Management of Sony Group Corp. provided conservative commentary on near-term gaming segment margins given higher hardware and marketing costs for its Playstation 5 console. Yum China Holdings, Inc., the parent company of KFC and Pizza Hut and a major player in the Chinese fast-food market, underperformed along with broader negative sentiment and weakness in the Chinese market. 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: June 1, 2014 through May 31, 2024 Initial 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 10 Years Investor A Shares 15.12 % 7.68 % 4.36 % Investor A Shares (with sales charge) 9.08 % 6.52 % 3.80 % MSCI ACWI ex USA Index 16.74 % 6.81 % 4.03 % |
| 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 | $ 1,725,206,070 |
| Holdings Count | Holding | 33 |
| Advisory Fees Paid, Amount | $ 9,808,933 |
| Investment Company Portfolio Turnover | 86% |
| 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 May 31, 2024) Geographic allocation Country Percent of Japan 15.4 % Germany 12.5 % United States 12.1 % United Kingdom 10.3 % Canada 10.3 % France 9.0 % Netherlands 6.3 % Denmark 6.1 % China 3.9 % Italy 3.8 % Other 8.0 % Short-Term Securities 2.1 % Other Assets Less Liabilities 0.2 % Ten largest holdings Security (a) Percent of Novo Nordisk A/S, Class B 6.1 % Beiersdorf AG 5.4 % Sony Group Corp. 5.3 % Recruit Holdings Co. Ltd. 4.8 % Canadian National Railway Co. 4.8 % ASML Holding NV 4.7 % Mastercard, Inc., Class A 4.5 % Deutsche Telekom AG, Registered Shares 4.0 % Canadian Pacific Kansas City Ltd. 4.0 % Tencent Holdings Ltd. 3.9 % (a) Excludes short-term securities. |
| Largest Holdings [Text Block] | Ten largest holdings Security (a) Percent of Novo Nordisk A/S, Class B 6.1 % Beiersdorf AG 5.4 % Sony Group Corp. 5.3 % Recruit Holdings Co. Ltd. 4.8 % Canadian National Railway Co. 4.8 % ASML Holding NV 4.7 % Mastercard, Inc., Class A 4.5 % Deutsche Telekom AG, Registered Shares 4.0 % Canadian Pacific Kansas City Ltd. 4.0 % Tencent Holdings Ltd. 3.9 % (a) Excludes short-term securities. |
| Shareholder Report, Line Graph (Details) - USD ($) | 12 Months Ended | 60 Months Ended | 120 Months Ended | |||||||||
| May 31, 2024 | May 31, 2024 | May 31, 2024 | May 31, 2023 | May 31, 2022 | May 31, 2021 | May 31, 2020 | May 31, 2019 | May 31, 2018 | May 31, 2017 | May 31, 2016 | May 31, 2015 | |
| C000198221 [Member] | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Class K Shares | |||||||||||
| Account Value | $ 15,850 | $ 15,850 | $ 15,850 | $ 13,720 | $ 13,794 | $ 17,708 | $ 11,335 | $ 10,781 | $ 11,538 | $ 10,813 | $ 9,153 | $ 10,207 |
| Average Annual Return, Percent | 15.52% | 8.01% | 4.71% | |||||||||
| C000005984 [Member] | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Institutional Shares | |||||||||||
| Account Value | $ 15,787 | $ 15,787 | $ 15,787 | 13,671 | 13,753 | 17,671 | 11,317 | 10,770 | 11,531 | 10,813 | 9,153 | 10,207 |
| Average Annual Return, Percent | 15.47% | 7.95% | 4.67% | |||||||||
| C000005983 [Member] | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Investor C Shares (with sales charge) | |||||||||||
| Account Value | $ 14,310 | $ 14,310 | $ 14,310 | 12,431 | 12,528 | 16,259 | 10,519 | 10,107 | 10,937 | 10,371 | 8,904 | 10,069 |
| Average Annual Return, Percent | 13.34% | 6.88% | 3.65% | |||||||||
| C000005983 [Member] | Without Sales Load [Member] | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Investor C Shares | |||||||||||
| Average Annual Return, Percent | 14.34% | 6.88% | 3.65% | |||||||||
| C000101856 [Member] | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Class R Shares | |||||||||||
| Account Value | $ 14,910 | $ 14,910 | $ 14,910 | 12,985 | 13,121 | 16,941 | 10,904 | 10,429 | 11,230 | 10,587 | 9,022 | 10,133 |
| Average Annual Return, Percent | 14.83% | 7.41% | 4.08% | |||||||||
| C000005981 [Member] | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Investor A Shares (with sales charge) | |||||||||||
| Account Value | $ 14,520 | $ 14,520 | $ 14,520 | 12,613 | 12,711 | 16,372 | 10,512 | 10,030 | 10,771 | 10,128 | 8,606 | 9,631 |
| Average Annual Return, Percent | 9.08% | 6.52% | 3.80% | |||||||||
| C000005981 [Member] | Without Sales Load [Member] | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Investor A Shares | |||||||||||
| Average Annual Return, Percent | 15.12% | 7.68% | 4.36% | |||||||||
| MSCI ACWI ex USA Index [Member] | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | MSCI ACWI ex USA Index | |||||||||||
| Account Value | $ 14,838 | $ 14,838 | $ 14,838 | $ 12,710 | $ 12,891 | $ 14,717 | $ 10,308 | $ 10,675 | $ 11,387 | $ 10,383 | $ 8,781 | $ 9,910 |
| Average Annual Return, Percent | 16.74% | 6.81% | 4.03% |
| Shareholder Report, Holdings (Details) | May 31, 2024 | |
| C000198221 [Member] | Novo Nordisk A S Class B [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.10% | [1] |
| C000198221 [Member] | Sony Group Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.30% | [1] |
| C000198221 [Member] | Beiersdorf AG [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.40% | [1] |
| C000198221 [Member] | Deutsche Telekom AG Registered Shares [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4% | [1] |
| C000198221 [Member] | Canadian Pacific Kansas City Ltd [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4% | [1] |
| C000198221 [Member] | Mastercard Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.50% | [1] |
| C000198221 [Member] | Recruit Holdings Co Ltd [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.80% | [1] |
| C000198221 [Member] | ASML Holding NV [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.70% | [1] |
| C000198221 [Member] | Canadian National Railway Co [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.80% | [1] |
| C000198221 [Member] | Tencent Holdings Ltd [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.90% | [1] |
| C000198221 [Member] | Other [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 8% | |
| C000198221 [Member] | UNITED KINGDOM | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.30% | |
| C000198221 [Member] | NETHERLANDS | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.30% | |
| C000198221 [Member] | UNITED STATES | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.10% | |
| C000198221 [Member] | GERMANY | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.50% | |
| C000198221 [Member] | JAPAN | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 15.40% | |
| C000198221 [Member] | FRANCE | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 9% | |
| C000198221 [Member] | DENMARK | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.10% | |
| C000198221 [Member] | CANADA | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.30% | |
| C000198221 [Member] | CHINA | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.90% | |
| C000198221 [Member] | ITALY | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.80% | |
| C000198221 [Member] | Other Assets Less Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.20% | |
| C000198221 [Member] | Short Term Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2.10% | |
| C000005984 [Member] | Novo Nordisk A S Class B [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.10% | [2] |
| C000005984 [Member] | Sony Group Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.30% | [2] |
| C000005984 [Member] | Beiersdorf AG [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.40% | [2] |
| C000005984 [Member] | Deutsche Telekom AG Registered Shares [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4% | [2] |
| C000005984 [Member] | Canadian Pacific Kansas City Ltd [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4% | [2] |
| C000005984 [Member] | Mastercard Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.50% | [2] |
| C000005984 [Member] | Recruit Holdings Co Ltd [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.80% | [2] |
| C000005984 [Member] | ASML Holding NV [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.70% | [2] |
| C000005984 [Member] | Canadian National Railway Co [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.80% | [2] |
| C000005984 [Member] | Tencent Holdings Ltd [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.90% | [2] |
| C000005984 [Member] | Other [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 8% | |
| C000005984 [Member] | UNITED KINGDOM | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.30% | |
| C000005984 [Member] | NETHERLANDS | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.30% | |
| C000005984 [Member] | UNITED STATES | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.10% | |
| C000005984 [Member] | GERMANY | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.50% | |
| C000005984 [Member] | JAPAN | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 15.40% | |
| C000005984 [Member] | FRANCE | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 9% | |
| C000005984 [Member] | DENMARK | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.10% | |
| C000005984 [Member] | CANADA | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.30% | |
| C000005984 [Member] | CHINA | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.90% | |
| C000005984 [Member] | ITALY | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.80% | |
| C000005984 [Member] | Other Assets Less Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.20% | |
| C000005984 [Member] | Short Term Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2.10% | |
| C000005983 [Member] | Novo Nordisk A S Class B [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.10% | [3] |
| C000005983 [Member] | Sony Group Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.30% | [3] |
| C000005983 [Member] | Beiersdorf AG [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.40% | [3] |
| C000005983 [Member] | Deutsche Telekom AG Registered Shares [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4% | [3] |
| C000005983 [Member] | Canadian Pacific Kansas City Ltd [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4% | [3] |
| C000005983 [Member] | Mastercard Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.50% | [3] |
| C000005983 [Member] | Recruit Holdings Co Ltd [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.80% | [3] |
| C000005983 [Member] | ASML Holding NV [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.70% | [3] |
| C000005983 [Member] | Canadian National Railway Co [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.80% | [3] |
| C000005983 [Member] | Tencent Holdings Ltd [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.90% | [3] |
| C000005983 [Member] | Other [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 8% | |
| C000005983 [Member] | UNITED KINGDOM | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.30% | |
| C000005983 [Member] | NETHERLANDS | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.30% | |
| C000005983 [Member] | UNITED STATES | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.10% | |
| C000005983 [Member] | GERMANY | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.50% | |
| C000005983 [Member] | JAPAN | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 15.40% | |
| C000005983 [Member] | FRANCE | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 9% | |
| C000005983 [Member] | DENMARK | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.10% | |
| C000005983 [Member] | CANADA | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.30% | |
| C000005983 [Member] | CHINA | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.90% | |
| C000005983 [Member] | ITALY | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.80% | |
| C000005983 [Member] | Other Assets Less Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.20% | |
| C000005983 [Member] | Short Term Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2.10% | |
| C000101856 [Member] | Novo Nordisk A S Class B [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.10% | [4] |
| C000101856 [Member] | Sony Group Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.30% | [4] |
| C000101856 [Member] | Beiersdorf AG [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.40% | [4] |
| C000101856 [Member] | Deutsche Telekom AG Registered Shares [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4% | [4] |
| C000101856 [Member] | Canadian Pacific Kansas City Ltd [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4% | [4] |
| C000101856 [Member] | Mastercard Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.50% | [4] |
| C000101856 [Member] | Recruit Holdings Co Ltd [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.80% | [4] |
| C000101856 [Member] | ASML Holding NV [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.70% | [4] |
| C000101856 [Member] | Canadian National Railway Co [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.80% | [4] |
| C000101856 [Member] | Tencent Holdings Ltd [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.90% | [4] |
| C000101856 [Member] | Other [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 8% | |
| C000101856 [Member] | UNITED KINGDOM | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.30% | |
| C000101856 [Member] | NETHERLANDS | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.30% | |
| C000101856 [Member] | UNITED STATES | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.10% | |
| C000101856 [Member] | GERMANY | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.50% | |
| C000101856 [Member] | JAPAN | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 15.40% | |
| C000101856 [Member] | FRANCE | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 9% | |
| C000101856 [Member] | DENMARK | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.10% | |
| C000101856 [Member] | CANADA | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.30% | |
| C000101856 [Member] | CHINA | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.90% | |
| C000101856 [Member] | ITALY | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.80% | |
| C000101856 [Member] | Other Assets Less Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.20% | |
| C000101856 [Member] | Short Term Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2.10% | |
| C000005981 [Member] | Novo Nordisk A S Class B [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.10% | [5] |
| C000005981 [Member] | Sony Group Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.30% | [5] |
| C000005981 [Member] | Beiersdorf AG [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.40% | [5] |
| C000005981 [Member] | Deutsche Telekom AG Registered Shares [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4% | [5] |
| C000005981 [Member] | Canadian Pacific Kansas City Ltd [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4% | [5] |
| C000005981 [Member] | Mastercard Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.50% | [5] |
| C000005981 [Member] | Recruit Holdings Co Ltd [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.80% | [5] |
| C000005981 [Member] | ASML Holding NV [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.70% | [5] |
| C000005981 [Member] | Canadian National Railway Co [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 4.80% | [5] |
| C000005981 [Member] | Tencent Holdings Ltd [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.90% | [5] |
| C000005981 [Member] | Other [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 8% | |
| C000005981 [Member] | UNITED KINGDOM | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.30% | |
| C000005981 [Member] | NETHERLANDS | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.30% | |
| C000005981 [Member] | UNITED STATES | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.10% | |
| C000005981 [Member] | GERMANY | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 12.50% | |
| C000005981 [Member] | JAPAN | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 15.40% | |
| C000005981 [Member] | FRANCE | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 9% | |
| C000005981 [Member] | DENMARK | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 6.10% | |
| C000005981 [Member] | CANADA | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 10.30% | |
| C000005981 [Member] | CHINA | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.90% | |
| C000005981 [Member] | ITALY | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.80% | |
| C000005981 [Member] | Other Assets Less Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.20% | |
| C000005981 [Member] | Short Term Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2.10% | |
| [1]Excludes short-term securities.[2]Excludes short-term securities.[3]Excludes short-term securities.[4]Excludes short-term securities.[5]Excludes short-term securities. | ||
