| Form N-CSR Cover | 12 Months Ended |
| Aug. 31, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | MFS SERIES TRUST IV |
| Entity Central Index Key | 0000063068 |
| Document Period End Date | Aug. 31, 2024 |
| Shareholder Report | 12 Months Ended | |
| Aug. 31, 2024 USD ($) Holding | ||
| Shareholder Report [Line Items] | ||
| Document Type | N-CSR | |
| Amendment Flag | false | |
| Registrant Name | MFS SERIES TRUST IV | |
| Entity Central Index Key | 0000063068 | |
| Document Period End Date | Aug. 31, 2024 | |
| C000107817 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Global New Discovery Fund | |
| Class Name | Class A | |
| Trading Symbol | GLNAX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Global New Discovery Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment A $ 1.35 % | |
| Expenses Paid, Amount | $ 144 | |
| Expense Ratio, Percent | 1.35% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class A shares of the MFS Global New Discovery Fund (fund) provided a total return of 13.42%, at net asset value. This compares with a return of 23.44% for the fund’s benchmark, the MSCI All Country World Index (net div). The fund's other benchmark, the MSCI All Country World Small Mid Cap Index (net div), generated a return of 16.90%. As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI All Country World Small Mid Cap Index: Security selection and, to a lesser extent, an overweight position in the industrials sector contributed to relative performance. Security selection within the consumer staples sector also helped relative returns. Top detractors from performance relative to the MSCI All Country World Small Mid Cap Index: Stock selection within both the consumer discretionary and health care sectors detracted from relative performance. Stock selection and an underweight position in the financials sector hindered relative results. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment This graph shows the performance of a hypothetical $10,000 investment in Class A over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods. Share Class 1-yr 5-yr 10-yr A without sales charge 13.42 % 7.23 % 7.47 % A with initial sales charge (5.75%) 6.90 % 5.96 % 6.84 % Comparative Benchmark(s) MSCI All Country World Index (net div) +∆ 23.44 % 12.14 % 8.78 % MSCI All Country World Small Mid Cap Index (net div) +∆ 16.90 % 9.12 % 6.87 % + Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests. ∆ Source: FactSet Research Systems Inc. | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Performance Table Market Index Changed [Text Block] | Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/a | |
| Net Assets | $ 77,909,171 | |
| Holdings Count | Holding | 95 | |
| Advisory Fees Paid, Amount | $ 696,463 | [1] |
| Investment Company Portfolio Turnover | 37% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 77,909,171 Total Management Fee ($)#: 696,463 Total Number of Holdings: 95 Portfolio Turnover Rate (%): 37 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 97.2 % Money Market Funds 2.8 % Top ten holdings Cranswick PLC 2.6 % GFL Environmental, Inc. 2.4 % Wabtec Corp. 2.2 % ICON PLC 2.1 % Howmet Aerospace, Inc. 2.0 % Euronext N.V. 2.0 % AUB Group Ltd. 2.0 % STERIS PLC 1.9 % Burlington Stores, Inc. 1.8 % Jacobs Solutions, Inc. 1.7 % Issuer country weightings United States 43.8 % United Kingdom 11.1 % Japan 8.6 % Germany 5.4 % Canada 5.4 % France 4.6 % Brazil 3.3 % Australia 2.9 % Switzerland 2.9 % Other Countries 12.0 % | |
| Largest Holdings [Text Block] | Top ten holdings Cranswick PLC 2.6 % GFL Environmental, Inc. 2.4 % Wabtec Corp. 2.2 % ICON PLC 2.1 % Howmet Aerospace, Inc. 2.0 % Euronext N.V. 2.0 % AUB Group Ltd. 2.0 % STERIS PLC 1.9 % Burlington Stores, Inc. 1.8 % Jacobs Solutions, Inc. 1.7 % | |
| C000107818 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Global New Discovery Fund | |
| Class Name | Class B | |
| Trading Symbol | GLNBX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Global New Discovery Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment B $ 2.10 % | |
| Expenses Paid, Amount | $ 223 | |
| Expense Ratio, Percent | 2.10% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class B shares of the MFS Global New Discovery Fund (fund) provided a total return of 12.52%, at net asset value. This compares with a return of 23.44% for the fund’s benchmark, the MSCI All Country World Index (net div). The fund's other benchmark, the MSCI All Country World Small Mid Cap Index (net div), generated a return of 16.90%. As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI All Country World Small Mid Cap Index: Security selection and, to a lesser extent, an overweight position in the industrials sector contributed to relative performance. Security selection within the consumer staples sector also helped relative returns. Top detractors from performance relative to the MSCI All Country World Small Mid Cap Index: Stock selection within both the consumer discretionary and health care sectors detracted from relative performance. Stock selection and an underweight position in the financials sector hindered relative results. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment This graph shows the performance of a hypothetical $10,000 investment in Class B over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods. Share Class 1-yr 5-yr 10-yr B without sales charge 12.52 % 6.42 % 6.67 % B with CDSC (declining over six years from 4% to 0%) × 8.52 % 6.10 % 6.67 % Comparative Benchmark(s) MSCI All Country World Index (net div) +∆ 23.44 % 12.14 % 8.78 % MSCI All Country World Small Mid Cap Index (net div) +∆ 16.90 % 9.12 % 6.87 % + Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests. ∆ Source: FactSet Research Systems Inc. × Assuming redemption at the end of the applicable period. | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Performance Table Market Index Changed [Text Block] | Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/b | |
| Net Assets | $ 77,909,171 | |
| Holdings Count | Holding | 95 | |
| Advisory Fees Paid, Amount | $ 696,463 | [2] |
| Investment Company Portfolio Turnover | 37% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 77,909,171 Total Management Fee ($)#: 696,463 Total Number of Holdings: 95 Portfolio Turnover Rate (%): 37 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 97.2 % Money Market Funds 2.8 % Top ten holdings Cranswick PLC 2.6 % GFL Environmental, Inc. 2.4 % Wabtec Corp. 2.2 % ICON PLC 2.1 % Howmet Aerospace, Inc. 2.0 % Euronext N.V. 2.0 % AUB Group Ltd. 2.0 % STERIS PLC 1.9 % Burlington Stores, Inc. 1.8 % Jacobs Solutions, Inc. 1.7 % Issuer country weightings United States 43.8 % United Kingdom 11.1 % Japan 8.6 % Germany 5.4 % Canada 5.4 % France 4.6 % Brazil 3.3 % Australia 2.9 % Switzerland 2.9 % Other Countries 12.0 % | |
| Largest Holdings [Text Block] | Top ten holdings Cranswick PLC 2.6 % GFL Environmental, Inc. 2.4 % Wabtec Corp. 2.2 % ICON PLC 2.1 % Howmet Aerospace, Inc. 2.0 % Euronext N.V. 2.0 % AUB Group Ltd. 2.0 % STERIS PLC 1.9 % Burlington Stores, Inc. 1.8 % Jacobs Solutions, Inc. 1.7 % | |
| C000107819 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Global New Discovery Fund | |
| Class Name | Class C | |
| Trading Symbol | GLNCX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Global New Discovery Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment C $ 2.10 % | |
| Expenses Paid, Amount | $ 223 | |
| Expense Ratio, Percent | 2.10% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class C shares of the MFS Global New Discovery Fund (fund) provided a total return of 12.58%, at net asset value. This compares with a return of 23.44% for the fund’s benchmark, the MSCI All Country World Index (net div). The fund's other benchmark, the MSCI All Country World Small Mid Cap Index (net div), generated a return of 16.90%. As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI All Country World Small Mid Cap Index: Security selection and, to a lesser extent, an overweight position in the industrials sector contributed to relative performance. Security selection within the consumer staples sector also helped relative returns. Top detractors from performance relative to the MSCI All Country World Small Mid Cap Index: Stock selection within both the consumer discretionary and health care sectors detracted from relative performance. Stock selection and an underweight position in the financials sector hindered relative results. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment This graph shows the performance of a hypothetical $10,000 investment in Class C over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods. Share Class 1-yr 5-yr 10-yr C without sales charge 12.58 % 6.42 % 6.67 % C with CDSC (1% for 12 months) × 11.58 % 6.42 % 6.67 % Comparative Benchmark(s) MSCI All Country World Index (net div) +∆ 23.44 % 12.14 % 8.78 % MSCI All Country World Small Mid Cap Index (net div) +∆ 16.90 % 9.12 % 6.87 % + Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests. ∆ Source: FactSet Research Systems Inc. × Assuming redemption at the end of the applicable period. | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Performance Table Market Index Changed [Text Block] | Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/c | |
| Net Assets | $ 77,909,171 | |
| Holdings Count | Holding | 95 | |
| Advisory Fees Paid, Amount | $ 696,463 | [3] |
| Investment Company Portfolio Turnover | 37% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 77,909,171 Total Management Fee ($)#: 696,463 Total Number of Holdings: 95 Portfolio Turnover Rate (%): 37 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 97.2 % Money Market Funds 2.8 % Top ten holdings Cranswick PLC 2.6 % GFL Environmental, Inc. 2.4 % Wabtec Corp. 2.2 % ICON PLC 2.1 % Howmet Aerospace, Inc. 2.0 % Euronext N.V. 2.0 % AUB Group Ltd. 2.0 % STERIS PLC 1.9 % Burlington Stores, Inc. 1.8 % Jacobs Solutions, Inc. 1.7 % Issuer country weightings United States 43.8 % United Kingdom 11.1 % Japan 8.6 % Germany 5.4 % Canada 5.4 % France 4.6 % Brazil 3.3 % Australia 2.9 % Switzerland 2.9 % Other Countries 12.0 % | |
| Largest Holdings [Text Block] | Top ten holdings Cranswick PLC 2.6 % GFL Environmental, Inc. 2.4 % Wabtec Corp. 2.2 % ICON PLC 2.1 % Howmet Aerospace, Inc. 2.0 % Euronext N.V. 2.0 % AUB Group Ltd. 2.0 % STERIS PLC 1.9 % Burlington Stores, Inc. 1.8 % Jacobs Solutions, Inc. 1.7 % | |
| C000107820 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Global New Discovery Fund | |
| Class Name | Class I | |
| Trading Symbol | GLNIX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Global New Discovery Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment I $ 1.10 % | |
| Expenses Paid, Amount | $ 118 | |
| Expense Ratio, Percent | 1.10% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class I shares of the MFS Global New Discovery Fund (fund) provided a total return of 13.69%, at net asset value. This compares with a return of 23.44% for the fund’s benchmark, the MSCI All Country World Index (net div). The fund's other benchmark, the MSCI All Country World Small Mid Cap Index (net div), generated a return of 16.90%. As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI All Country World Small Mid Cap Index: Security selection and, to a lesser extent, an overweight position in the industrials sector contributed to relative performance. Security selection within the consumer staples sector also helped relative returns. Top detractors from performance relative to the MSCI All Country World Small Mid Cap Index: Stock selection within both the consumer discretionary and health care sectors detracted from relative performance. Stock selection and an underweight position in the financials sector hindered relative results. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment This graph shows the performance of a hypothetical $10,000 investment in Class I over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods. Share Class 1-yr 5-yr 10-yr I without sales charge 13.69 % 7.49 % 7.74 % Comparative Benchmark(s) MSCI All Country World Index (net div) +∆ 23.44 % 12.14 % 8.78 % MSCI All Country World Small Mid Cap Index (net div) +∆ 16.90 % 9.12 % 6.87 % + Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests. ∆ Source: FactSet Research Systems Inc. | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Performance Table Market Index Changed [Text Block] | Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/i | |
| Net Assets | $ 77,909,171 | |
| Holdings Count | Holding | 95 | |
| Advisory Fees Paid, Amount | $ 696,463 | [4] |
| Investment Company Portfolio Turnover | 37% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 77,909,171 Total Management Fee ($)#: 696,463 Total Number of Holdings: 95 Portfolio Turnover Rate (%): 37 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 97.2 % Money Market Funds 2.8 % Top ten holdings Cranswick PLC 2.6 % GFL Environmental, Inc. 2.4 % Wabtec Corp. 2.2 % ICON PLC 2.1 % Howmet Aerospace, Inc. 2.0 % Euronext N.V. 2.0 % AUB Group Ltd. 2.0 % STERIS PLC 1.9 % Burlington Stores, Inc. 1.8 % Jacobs Solutions, Inc. 1.7 % Issuer country weightings United States 43.8 % United Kingdom 11.1 % Japan 8.6 % Germany 5.4 % Canada 5.4 % France 4.6 % Brazil 3.3 % Australia 2.9 % Switzerland 2.9 % Other Countries 12.0 % | |
| Largest Holdings [Text Block] | Top ten holdings Cranswick PLC 2.6 % GFL Environmental, Inc. 2.4 % Wabtec Corp. 2.2 % ICON PLC 2.1 % Howmet Aerospace, Inc. 2.0 % Euronext N.V. 2.0 % AUB Group Ltd. 2.0 % STERIS PLC 1.9 % Burlington Stores, Inc. 1.8 % Jacobs Solutions, Inc. 1.7 % | |
| C000107821 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Global New Discovery Fund | |
| Class Name | Class R1 | |
| Trading Symbol | GLNJX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Global New Discovery Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R1 $ 2.10 % | |
| Expenses Paid, Amount | $ 223 | |
| Expense Ratio, Percent | 2.10% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R1 shares of the MFS Global New Discovery Fund (fund) provided a total return of 12.59%, at net asset value. This compares with a return of 23.44% for the fund’s benchmark, the MSCI All Country World Index (net div). The fund's other benchmark, the MSCI All Country World Small Mid Cap Index (net div), generated a return of 16.90%. As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI All Country World Small Mid Cap Index: Security selection and, to a lesser extent, an overweight position in the industrials sector contributed to relative performance. Security selection within the consumer staples sector also helped relative returns. Top detractors from performance relative to the MSCI All Country World Small Mid Cap Index: Stock selection within both the consumer discretionary and health care sectors detracted from relative performance. Stock selection and an underweight position in the financials sector hindered relative results. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment This graph shows the performance of a hypothetical $10,000 investment in Class R1 over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods. Share Class 1-yr 5-yr 10-yr R1 without sales charge 12.59 % 6.42 % 6.67 % Comparative Benchmark(s) MSCI All Country World Index (net div) +∆ 23.44 % 12.14 % 8.78 % MSCI All Country World Small Mid Cap Index (net div) +∆ 16.90 % 9.12 % 6.87 % + Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests. ∆ Source: FactSet Research Systems Inc. | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Performance Table Market Index Changed [Text Block] | Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r1 | |
| Net Assets | $ 77,909,171 | |
| Holdings Count | Holding | 95 | |
| Advisory Fees Paid, Amount | $ 696,463 | [5] |
| Investment Company Portfolio Turnover | 37% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 77,909,171 Total Management Fee ($)#: 696,463 Total Number of Holdings: 95 Portfolio Turnover Rate (%): 37 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 97.2 % Money Market Funds 2.8 % Top ten holdings Cranswick PLC 2.6 % GFL Environmental, Inc. 2.4 % Wabtec Corp. 2.2 % ICON PLC 2.1 % Howmet Aerospace, Inc. 2.0 % Euronext N.V. 2.0 % AUB Group Ltd. 2.0 % STERIS PLC 1.9 % Burlington Stores, Inc. 1.8 % Jacobs Solutions, Inc. 1.7 % Issuer country weightings United States 43.8 % United Kingdom 11.1 % Japan 8.6 % Germany 5.4 % Canada 5.4 % France 4.6 % Brazil 3.3 % Australia 2.9 % Switzerland 2.9 % Other Countries 12.0 % | |
| Largest Holdings [Text Block] | Top ten holdings Cranswick PLC 2.6 % GFL Environmental, Inc. 2.4 % Wabtec Corp. 2.2 % ICON PLC 2.1 % Howmet Aerospace, Inc. 2.0 % Euronext N.V. 2.0 % AUB Group Ltd. 2.0 % STERIS PLC 1.9 % Burlington Stores, Inc. 1.8 % Jacobs Solutions, Inc. 1.7 % | |
| C000107822 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Global New Discovery Fund | |
| Class Name | Class R2 | |
| Trading Symbol | GLNKX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Global New Discovery Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R2 $ 1.60 % | |
| Expenses Paid, Amount | $ 170 | |
| Expense Ratio, Percent | 1.60% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R2 shares of the MFS Global New Discovery Fund (fund) provided a total return of 13.12%, at net asset value. This compares with a return of 23.44% for the fund’s benchmark, the MSCI All Country World Index (net div). The fund's other benchmark, the MSCI All Country World Small Mid Cap Index (net div), generated a return of 16.90%. As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI All Country World Small Mid Cap Index: Security selection and, to a lesser extent, an overweight position in the industrials sector contributed to relative performance. Security selection within the consumer staples sector also helped relative returns. Top detractors from performance relative to the MSCI All Country World Small Mid Cap Index: Stock selection within both the consumer discretionary and health care sectors detracted from relative performance. Stock selection and an underweight position in the financials sector hindered relative results. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment This graph shows the performance of a hypothetical $10,000 investment in Class R2 over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods. Share Class 1-yr 5-yr 10-yr R2 without sales charge 13.12 % 6.95 % 7.20 % Comparative Benchmark(s) MSCI All Country World Index (net div) +∆ 23.44 % 12.14 % 8.78 % MSCI All Country World Small Mid Cap Index (net div) +∆ 16.90 % 9.12 % 6.87 % + Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests. ∆ Source: FactSet Research Systems Inc. | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Performance Table Market Index Changed [Text Block] | Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r2 | |
| Net Assets | $ 77,909,171 | |
| Holdings Count | Holding | 95 | |
| Advisory Fees Paid, Amount | $ 696,463 | [6] |
| Investment Company Portfolio Turnover | 37% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 77,909,171 Total Management Fee ($)#: 696,463 Total Number of Holdings: 95 Portfolio Turnover Rate (%): 37 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 97.2 % Money Market Funds 2.8 % Top ten holdings Cranswick PLC 2.6 % GFL Environmental, Inc. 2.4 % Wabtec Corp. 2.2 % ICON PLC 2.1 % Howmet Aerospace, Inc. 2.0 % Euronext N.V. 2.0 % AUB Group Ltd. 2.0 % STERIS PLC 1.9 % Burlington Stores, Inc. 1.8 % Jacobs Solutions, Inc. 1.7 % Issuer country weightings United States 43.8 % United Kingdom 11.1 % Japan 8.6 % Germany 5.4 % Canada 5.4 % France 4.6 % Brazil 3.3 % Australia 2.9 % Switzerland 2.9 % Other Countries 12.0 % | |
| Largest Holdings [Text Block] | Top ten holdings Cranswick PLC 2.6 % GFL Environmental, Inc. 2.4 % Wabtec Corp. 2.2 % ICON PLC 2.1 % Howmet Aerospace, Inc. 2.0 % Euronext N.V. 2.0 % AUB Group Ltd. 2.0 % STERIS PLC 1.9 % Burlington Stores, Inc. 1.8 % Jacobs Solutions, Inc. 1.7 % | |
| C000107823 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Global New Discovery Fund | |
| Class Name | Class R3 | |
| Trading Symbol | GLNLX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Global New Discovery Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R3 $ 1.35 % | |
| Expenses Paid, Amount | $ 144 | |
| Expense Ratio, Percent | 1.35% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R3 shares of the MFS Global New Discovery Fund (fund) provided a total return of 13.38%, at net asset value. This compares with a return of 23.44% for the fund’s benchmark, the MSCI All Country World Index (net div). The fund's other benchmark, the MSCI All Country World Small Mid Cap Index (net div), generated a return of 16.90%. As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI All Country World Small Mid Cap Index: Security selection and, to a lesser extent, an overweight position in the industrials sector contributed to relative performance. Security selection within the consumer staples sector also helped relative returns. Top detractors from performance relative to the MSCI All Country World Small Mid Cap Index: Stock selection within both the consumer discretionary and health care sectors detracted from relative performance. Stock selection and an underweight position in the financials sector hindered relative results. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment This graph shows the performance of a hypothetical $10,000 investment in Class R3 over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods. Share Class 1-yr 5-yr 10-yr R3 without sales charge 13.38 % 7.22 % 7.47 % Comparative Benchmark(s) MSCI All Country World Index (net div) +∆ 23.44 % 12.14 % 8.78 % MSCI All Country World Small Mid Cap Index (net div) +∆ 16.90 % 9.12 % 6.87 % + Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests. ∆ Source: FactSet Research Systems Inc. | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Performance Table Market Index Changed [Text Block] | Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r3 | |
| Net Assets | $ 77,909,171 | |
| Holdings Count | Holding | 95 | |
| Advisory Fees Paid, Amount | $ 696,463 | [7] |
| Investment Company Portfolio Turnover | 37% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 77,909,171 Total Management Fee ($)#: 696,463 Total Number of Holdings: 95 Portfolio Turnover Rate (%): 37 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 97.2 % Money Market Funds 2.8 % Top ten holdings Cranswick PLC 2.6 % GFL Environmental, Inc. 2.4 % Wabtec Corp. 2.2 % ICON PLC 2.1 % Howmet Aerospace, Inc. 2.0 % Euronext N.V. 2.0 % AUB Group Ltd. 2.0 % STERIS PLC 1.9 % Burlington Stores, Inc. 1.8 % Jacobs Solutions, Inc. 1.7 % Issuer country weightings United States 43.8 % United Kingdom 11.1 % Japan 8.6 % Germany 5.4 % Canada 5.4 % France 4.6 % Brazil 3.3 % Australia 2.9 % Switzerland 2.9 % Other Countries 12.0 % | |
| Largest Holdings [Text Block] | Top ten holdings Cranswick PLC 2.6 % GFL Environmental, Inc. 2.4 % Wabtec Corp. 2.2 % ICON PLC 2.1 % Howmet Aerospace, Inc. 2.0 % Euronext N.V. 2.0 % AUB Group Ltd. 2.0 % STERIS PLC 1.9 % Burlington Stores, Inc. 1.8 % Jacobs Solutions, Inc. 1.7 % | |
| C000107824 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Global New Discovery Fund | |
| Class Name | Class R4 | |
| Trading Symbol | GLNMX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Global New Discovery Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R4 $ 1.10 % | |
| Expenses Paid, Amount | $ 118 | |
| Expense Ratio, Percent | 1.10% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R4 shares of the MFS Global New Discovery Fund (fund) provided a total return of 13.68%, at net asset value. This compares with a return of 23.44% for the fund’s benchmark, the MSCI All Country World Index (net div). The fund's other benchmark, the MSCI All Country World Small Mid Cap Index (net div), generated a return of 16.90%. As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI All Country World Small Mid Cap Index: Security selection and, to a lesser extent, an overweight position in the industrials sector contributed to relative performance. Security selection within the consumer staples sector also helped relative returns. Top detractors from performance relative to the MSCI All Country World Small Mid Cap Index: Stock selection within both the consumer discretionary and health care sectors detracted from relative performance. Stock selection and an underweight position in the financials sector hindered relative results. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment This graph shows the performance of a hypothetical $10,000 investment in Class R4 over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods. Share Class 1-yr 5-yr 10-yr R4 without sales charge 13.68 % 7.50 % 7.74 % Comparative Benchmark(s) MSCI All Country World Index (net div) +∆ 23.44 % 12.14 % 8.78 % MSCI All Country World Small Mid Cap Index (net div) +∆ 16.90 % 9.12 % 6.87 % + Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests. ∆ Source: FactSet Research Systems Inc. | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Performance Table Market Index Changed [Text Block] | Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r4 | |
| Net Assets | $ 77,909,171 | |
| Holdings Count | Holding | 95 | |
| Advisory Fees Paid, Amount | $ 696,463 | [8] |
| Investment Company Portfolio Turnover | 37% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 77,909,171 Total Management Fee ($)#: 696,463 Total Number of Holdings: 95 Portfolio Turnover Rate (%): 37 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 97.2 % Money Market Funds 2.8 % Top ten holdings Cranswick PLC 2.6 % GFL Environmental, Inc. 2.4 % Wabtec Corp. 2.2 % ICON PLC 2.1 % Howmet Aerospace, Inc. 2.0 % Euronext N.V. 2.0 % AUB Group Ltd. 2.0 % STERIS PLC 1.9 % Burlington Stores, Inc. 1.8 % Jacobs Solutions, Inc. 1.7 % Issuer country weightings United States 43.8 % United Kingdom 11.1 % Japan 8.6 % Germany 5.4 % Canada 5.4 % France 4.6 % Brazil 3.3 % Australia 2.9 % Switzerland 2.9 % Other Countries 12.0 % | |
| Largest Holdings [Text Block] | Top ten holdings Cranswick PLC 2.6 % GFL Environmental, Inc. 2.4 % Wabtec Corp. 2.2 % ICON PLC 2.1 % Howmet Aerospace, Inc. 2.0 % Euronext N.V. 2.0 % AUB Group Ltd. 2.0 % STERIS PLC 1.9 % Burlington Stores, Inc. 1.8 % Jacobs Solutions, Inc. 1.7 % | |
| C000124429 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Global New Discovery Fund | |
| Class Name | Class R6 | |
| Trading Symbol | GLNNX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Global New Discovery Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R6 $ 1.00 % | |
| Expenses Paid, Amount | $ 107 | |
| Expense Ratio, Percent | 1% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R6 shares of the MFS Global New Discovery Fund (fund) provided a total return of 13.81%, at net asset value. This compares with a return of 23.44% for the fund’s benchmark, the MSCI All Country World Index (net div). The fund's other benchmark, the MSCI All Country World Small Mid Cap Index (net div), generated a return of 16.90%. As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI All Country World Small Mid Cap Index: Security selection and, to a lesser extent, an overweight position in the industrials sector contributed to relative performance. Security selection within the consumer staples sector also helped relative returns. Top detractors from performance relative to the MSCI All Country World Small Mid Cap Index: Stock selection within both the consumer discretionary and health care sectors detracted from relative performance. Stock selection and an underweight position in the financials sector hindered relative results. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment This graph shows the performance of a hypothetical $10,000 investment in Class R6 over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods. Share Class 1-yr 5-yr 10-yr R6 without sales charge 13.81 % 7.59 % 7.85 % Comparative Benchmark(s) MSCI All Country World Index (net div) +∆ 23.44 % 12.14 % 8.78 % MSCI All Country World Small Mid Cap Index (net div) +∆ 16.90 % 9.12 % 6.87 % + Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests. ∆ Source: FactSet Research Systems Inc. | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Performance Table Market Index Changed [Text Block] | Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r6 | |
| Net Assets | $ 77,909,171 | |
| Holdings Count | Holding | 95 | |
| Advisory Fees Paid, Amount | $ 696,463 | [9] |
| Investment Company Portfolio Turnover | 37% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 77,909,171 Total Management Fee ($)#: 696,463 Total Number of Holdings: 95 Portfolio Turnover Rate (%): 37 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 97.2 % Money Market Funds 2.8 % Top ten holdings Cranswick PLC 2.6 % GFL Environmental, Inc. 2.4 % Wabtec Corp. 2.2 % ICON PLC 2.1 % Howmet Aerospace, Inc. 2.0 % Euronext N.V. 2.0 % AUB Group Ltd. 2.0 % STERIS PLC 1.9 % Burlington Stores, Inc. 1.8 % Jacobs Solutions, Inc. 1.7 % Issuer country weightings United States 43.8 % United Kingdom 11.1 % Japan 8.6 % Germany 5.4 % Canada 5.4 % France 4.6 % Brazil 3.3 % Australia 2.9 % Switzerland 2.9 % Other Countries 12.0 % | |
| Largest Holdings [Text Block] | Top ten holdings Cranswick PLC 2.6 % GFL Environmental, Inc. 2.4 % Wabtec Corp. 2.2 % ICON PLC 2.1 % Howmet Aerospace, Inc. 2.0 % Euronext N.V. 2.0 % AUB Group Ltd. 2.0 % STERIS PLC 1.9 % Burlington Stores, Inc. 1.8 % Jacobs Solutions, Inc. 1.7 % | |
| C000006517 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® U.S. Government Money Market Fund | |
| Class Name | MFS® U.S. Government Money Market Fund | |
| Trading Symbol | MCMXX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS U.S. Government Money Market Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Fund Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment MFS U.S. Government Money Market Fund $ 0.45 % | |
| Expenses Paid, Amount | $ 46 | |
| Expense Ratio, Percent | 0.45% | |
| Net Assets | $ 363,373,358 | |
| Holdings Count | Holding | 21 | |
| Advisory Fees Paid, Amount | $ 1,475,438 | [10] |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 363,373,358 Total Management Fee ($)#: $ Total Number of Holdings: 21 # | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure U.S. Treasury and U.S. Government Agency Securities and Equivalents 73.8 % Repurchase Agreements, collateralized by U.S. Treasury and/or U.S. Government Agency Securities 26.2 % Composition including fixed income credit quality A-1+ 62.9 % A-1 37.1 % Maturity breakdown 0 - 7 days 32.0 % 8 - 29 days 27.9 % 30 - 59 days 24.0 % 60 - 89 days 12.4 % 90 - 365 days 3.7 % Ratings are assigned to portfolio securities utilizing ratings from Moody’s, Fitch, and Standard & Poor’s rating agencies and applying the following hierarchy: If all three agencies provide a rating, the middle rating (after dropping the highest and lowest ratings) is assigned; if two of the three agencies rate a security, the lower of the two is assigned. Ratings are shown in the S&P scale. All ratings are subject to change. The fund did not hold unrated securities. The fund is not rated by these agencies. | |
| Credit Ratings Selection [Text Block] | Ratings are assigned to portfolio securities utilizing ratings from Moody’s, Fitch, and Standard & Poor’s rating agencies and applying the following hierarchy: If all three agencies provide a rating, the middle rating (after dropping the highest and lowest ratings) is assigned; if two of the three agencies rate a security, the lower of the two is assigned. Ratings are shown in the S&P scale. All ratings are subject to change. The fund did not hold unrated securities. The fund is not rated by these agencies. | |
| C000160011 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Blended Research® International Equity Fund | |
| Class Name | Class A | |
| Trading Symbol | BRXAX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Blended Research International Equity Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment A $ 0.89 % | |
| Expenses Paid, Amount | $ 99 | |
| Expense Ratio, Percent | 0.89% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class A shares of the MFS Blended Research International Equity Fund (fund) provided a total return of 22.08%, at net asset value. This compares with a return of 18.21% for the fund’s benchmark, the MSCI All Country World (ex-US) Index (net div). As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI All Country World (ex-US) Index: Security selection within the information technology, consumer staples, financials and consumer discretionary sectors contributed to relative results. Top detractors from performance relative to the MSCI All Country World (ex-US) Index: Stock selection within both the materials and communication services sectors detracted from relative performance. During the reporting period, the fund's relative currency exposure, resulting primarily from differences between the fund's and the benchmark's exposures to holdings of securities denominated in foreign currencies, was another detractor from relative performance. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment* This graph shows the performance of a hypothetical $10,000 investment in Class A over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods. Share Class 1-yr 5-yr Life* A without sales charge 22.08 % 9.75 % 7.01 % A with initial sales charge (5.75%) 15.06 % 8.46 % 6.30 % Comparative Benchmark(s) MSCI All Country World (ex-US) Index (net div) ∆ 18.21 % 7.56 % 6.74 % * For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024. ∆ Source: FactSet Research Systems Inc. | |
| Performance Inception Date | Sep. 15, 2015 | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/a | |
| Net Assets | $ 709,315,854 | |
| Holdings Count | Holding | 148 | |
| Advisory Fees Paid, Amount | $ 3,239,487 | [11] |
| Investment Company Portfolio Turnover | 51% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 709,315,854 Total Management Fee ($)#: 3,239,487 Total Number of Holdings: 148 Portfolio Turnover Rate (%): 51 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 99.2 % Money Market Funds 0.8 % Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd., ADR 2.9 % Roche Holding AG 2.4 % ASML Holding N.V. 1.7 % KDDI Corp. 1.7 % UBS Group AG 1.6 % Tata Consultancy Services Ltd. 1.6 % Tencent Holdings Ltd. 1.5 % Samsung Electronics Co. Ltd. 1.5 % Sanofi 1.5 % DBS Group Holdings Ltd. 1.5 % Issuer country weightings Japan 14.8 % United Kingdom 10.4 % France 10.3 % Canada 8.7 % China 7.0 % Taiwan 4.9 % South Korea 4.8 % Switzerland 4.6 % Netherlands 4.3 % Other Countries 30.2 % | |
| Largest Holdings [Text Block] | Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd., ADR 2.9 % Roche Holding AG 2.4 % ASML Holding N.V. 1.7 % KDDI Corp. 1.7 % UBS Group AG 1.6 % Tata Consultancy Services Ltd. 1.6 % Tencent Holdings Ltd. 1.5 % Samsung Electronics Co. Ltd. 1.5 % Sanofi 1.5 % DBS Group Holdings Ltd. 1.5 % | |
| C000160012 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Blended Research® International Equity Fund | |
| Class Name | Class B | |
| Trading Symbol | BRXBX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Blended Research International Equity Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment B $ 1.64 % | |
| Expenses Paid, Amount | $ 181 | |
| Expense Ratio, Percent | 1.64% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class B shares of the MFS Blended Research International Equity Fund (fund) provided a total return of 21.15%, at net asset value. This compares with a return of 18.21% for the fund’s benchmark, the MSCI All Country World (ex-US) Index (net div). As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI All Country World (ex-US) Index: Security selection within the information technology, consumer staples, financials and consumer discretionary sectors contributed to relative results. Top detractors from performance relative to the MSCI All Country World (ex-US) Index: Stock selection within both the materials and communication services sectors detracted from relative performance. During the reporting period, the fund's relative currency exposure, resulting primarily from differences between the fund's and the benchmark's exposures to holdings of securities denominated in foreign currencies, was another detractor from relative performance. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment* This graph shows the performance of a hypothetical $10,000 investment in Class B over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods. Share Class 1-yr 5-yr Life* B without sales charge 21.15 % 8.90 % 6.19 % B with CDSC (declining over six years from 4% to 0%) × 17.15 % 8.61 % 6.19 % Comparative Benchmark(s) MSCI All Country World (ex-US) Index (net div) ∆ 18.21 % 7.56 % 6.74 % * For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024. ∆ Source: FactSet Research Systems Inc. × Assuming redemption at the end of the applicable period. | |
| Performance Inception Date | Sep. 15, 2015 | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/b | |
| Net Assets | $ 709,315,854 | |
| Holdings Count | Holding | 148 | |
| Advisory Fees Paid, Amount | $ 3,239,487 | [12] |
| Investment Company Portfolio Turnover | 51% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 709,315,854 Total Management Fee ($)#: 3,239,487 Total Number of Holdings: 148 Portfolio Turnover Rate (%): 51 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 99.2 % Money Market Funds 0.8 % Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd., ADR 2.9 % Roche Holding AG 2.4 % ASML Holding N.V. 1.7 % KDDI Corp. 1.7 % UBS Group AG 1.6 % Tata Consultancy Services Ltd. 1.6 % Tencent Holdings Ltd. 1.5 % Samsung Electronics Co. Ltd. 1.5 % Sanofi 1.5 % DBS Group Holdings Ltd. 1.5 % Issuer country weightings Japan 14.8 % United Kingdom 10.4 % France 10.3 % Canada 8.7 % China 7.0 % Taiwan 4.9 % South Korea 4.8 % Switzerland 4.6 % Netherlands 4.3 % Other Countries 30.2 % | |
| Largest Holdings [Text Block] | Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd., ADR 2.9 % Roche Holding AG 2.4 % ASML Holding N.V. 1.7 % KDDI Corp. 1.7 % UBS Group AG 1.6 % Tata Consultancy Services Ltd. 1.6 % Tencent Holdings Ltd. 1.5 % Samsung Electronics Co. Ltd. 1.5 % Sanofi 1.5 % DBS Group Holdings Ltd. 1.5 % | |
| C000160013 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Blended Research® International Equity Fund | |
| Class Name | Class C | |
| Trading Symbol | BRXCX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Blended Research International Equity Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment C $ 1.64 % | |
| Expenses Paid, Amount | $ 181 | |
| Expense Ratio, Percent | 1.64% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class C shares of the MFS Blended Research International Equity Fund (fund) provided a total return of 21.20%, at net asset value. This compares with a return of 18.21% for the fund’s benchmark, the MSCI All Country World (ex-US) Index (net div). As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI All Country World (ex-US) Index: Security selection within the information technology, consumer staples, financials and consumer discretionary sectors contributed to relative results. Top detractors from performance relative to the MSCI All Country World (ex-US) Index: Stock selection within both the materials and communication services sectors detracted from relative performance. During the reporting period, the fund's relative currency exposure, resulting primarily from differences between the fund's and the benchmark's exposures to holdings of securities denominated in foreign currencies, was another detractor from relative performance. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment* This graph shows the performance of a hypothetical $10,000 investment in Class C over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods. Share Class 1-yr 5-yr Life* C without sales charge 21.20 % 8.91 % 6.19 % C with CDSC (1% for 12 months) × 20.20 % 8.91 % 6.19 % Comparative Benchmark(s) MSCI All Country World (ex-US) Index (net div) ∆ 18.21 % 7.56 % 6.74 % * For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024. ∆ Source: FactSet Research Systems Inc. × Assuming redemption at the end of the applicable period. | |
| Performance Inception Date | Sep. 15, 2015 | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/c | |
| Net Assets | $ 709,315,854 | |
| Holdings Count | Holding | 148 | |
| Advisory Fees Paid, Amount | $ 3,239,487 | [13] |
| Investment Company Portfolio Turnover | 51% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 709,315,854 Total Management Fee ($)#: 3,239,487 Total Number of Holdings: 148 Portfolio Turnover Rate (%): 51 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 99.2 % Money Market Funds 0.8 % Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd., ADR 2.9 % Roche Holding AG 2.4 % ASML Holding N.V. 1.7 % KDDI Corp. 1.7 % UBS Group AG 1.6 % Tata Consultancy Services Ltd. 1.6 % Tencent Holdings Ltd. 1.5 % Samsung Electronics Co. Ltd. 1.5 % Sanofi 1.5 % DBS Group Holdings Ltd. 1.5 % Issuer country weightings Japan 14.8 % United Kingdom 10.4 % France 10.3 % Canada 8.7 % China 7.0 % Taiwan 4.9 % South Korea 4.8 % Switzerland 4.6 % Netherlands 4.3 % Other Countries 30.2 % | |
| Largest Holdings [Text Block] | Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd., ADR 2.9 % Roche Holding AG 2.4 % ASML Holding N.V. 1.7 % KDDI Corp. 1.7 % UBS Group AG 1.6 % Tata Consultancy Services Ltd. 1.6 % Tencent Holdings Ltd. 1.5 % Samsung Electronics Co. Ltd. 1.5 % Sanofi 1.5 % DBS Group Holdings Ltd. 1.5 % | |
| C000160014 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Blended Research® International Equity Fund | |
| Class Name | Class I | |
| Trading Symbol | BRXIX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Blended Research International Equity Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment I $ 0.64 % | |
| Expenses Paid, Amount | $ 71 | |
| Expense Ratio, Percent | 0.64% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class I shares of the MFS Blended Research International Equity Fund (fund) provided a total return of 22.39%, at net asset value. This compares with a return of 18.21% for the fund’s benchmark, the MSCI All Country World (ex-US) Index (net div). As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI All Country World (ex-US) Index: Security selection within the information technology, consumer staples, financials and consumer discretionary sectors contributed to relative results. Top detractors from performance relative to the MSCI All Country World (ex-US) Index: Stock selection within both the materials and communication services sectors detracted from relative performance. During the reporting period, the fund's relative currency exposure, resulting primarily from differences between the fund's and the benchmark's exposures to holdings of securities denominated in foreign currencies, was another detractor from relative performance. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment* This graph shows the performance of a hypothetical $10,000 investment in Class I over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods. Share Class 1-yr 5-yr Life* I without sales charge 22.39 % 10.00 % 7.26 % Comparative Benchmark(s) MSCI All Country World (ex-US) Index (net div) ∆ 18.21 % 7.56 % 6.74 % * For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024. ∆ Source: FactSet Research Systems Inc. | |
| Performance Inception Date | Sep. 15, 2015 | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/i | |
| Net Assets | $ 709,315,854 | |
| Holdings Count | Holding | 148 | |
| Advisory Fees Paid, Amount | $ 3,239,487 | [14] |
| Investment Company Portfolio Turnover | 51% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 709,315,854 Total Management Fee ($)#: 3,239,487 Total Number of Holdings: 148 Portfolio Turnover Rate (%): 51 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 99.2 % Money Market Funds 0.8 % Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd., ADR 2.9 % Roche Holding AG 2.4 % ASML Holding N.V. 1.7 % KDDI Corp. 1.7 % UBS Group AG 1.6 % Tata Consultancy Services Ltd. 1.6 % Tencent Holdings Ltd. 1.5 % Samsung Electronics Co. Ltd. 1.5 % Sanofi 1.5 % DBS Group Holdings Ltd. 1.5 % Issuer country weightings Japan 14.8 % United Kingdom 10.4 % France 10.3 % Canada 8.7 % China 7.0 % Taiwan 4.9 % South Korea 4.8 % Switzerland 4.6 % Netherlands 4.3 % Other Countries 30.2 % | |
| Largest Holdings [Text Block] | Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd., ADR 2.9 % Roche Holding AG 2.4 % ASML Holding N.V. 1.7 % KDDI Corp. 1.7 % UBS Group AG 1.6 % Tata Consultancy Services Ltd. 1.6 % Tencent Holdings Ltd. 1.5 % Samsung Electronics Co. Ltd. 1.5 % Sanofi 1.5 % DBS Group Holdings Ltd. 1.5 % | |
| C000160015 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Blended Research® International Equity Fund | |
| Class Name | Class R1 | |
| Trading Symbol | BRXRX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Blended Research International Equity Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R1 $ 1.64 % | |
| Expenses Paid, Amount | $ 181 | |
| Expense Ratio, Percent | 1.64% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R1 shares of the MFS Blended Research International Equity Fund (fund) provided a total return of 21.25%, at net asset value. This compares with a return of 18.21% for the fund’s benchmark, the MSCI All Country World (ex-US) Index (net div). As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI All Country World (ex-US) Index: Security selection within the information technology, consumer staples, financials and consumer discretionary sectors contributed to relative results. Top detractors from performance relative to the MSCI All Country World (ex-US) Index: Stock selection within both the materials and communication services sectors detracted from relative performance. During the reporting period, the fund's relative currency exposure, resulting primarily from differences between the fund's and the benchmark's exposures to holdings of securities denominated in foreign currencies, was another detractor from relative performance. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment* This graph shows the performance of a hypothetical $10,000 investment in Class R1 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods. Share Class 1-yr 5-yr Life* R1 without sales charge 21.25 % 8.92 % 6.19 % Comparative Benchmark(s) MSCI All Country World (ex-US) Index (net div) ∆ 18.21 % 7.56 % 6.74 % * For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024. ∆ Source: FactSet Research Systems Inc. | |
| Performance Inception Date | Sep. 15, 2015 | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r1 | |
| Net Assets | $ 709,315,854 | |
| Holdings Count | Holding | 148 | |
| Advisory Fees Paid, Amount | $ 3,239,487 | [15] |
| Investment Company Portfolio Turnover | 51% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 709,315,854 Total Management Fee ($)#: 3,239,487 Total Number of Holdings: 148 Portfolio Turnover Rate (%): 51 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 99.2 % Money Market Funds 0.8 % Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd., ADR 2.9 % Roche Holding AG 2.4 % ASML Holding N.V. 1.7 % KDDI Corp. 1.7 % UBS Group AG 1.6 % Tata Consultancy Services Ltd. 1.6 % Tencent Holdings Ltd. 1.5 % Samsung Electronics Co. Ltd. 1.5 % Sanofi 1.5 % DBS Group Holdings Ltd. 1.5 % Issuer country weightings Japan 14.8 % United Kingdom 10.4 % France 10.3 % Canada 8.7 % China 7.0 % Taiwan 4.9 % South Korea 4.8 % Switzerland 4.6 % Netherlands 4.3 % Other Countries 30.2 % | |
| Largest Holdings [Text Block] | Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd., ADR 2.9 % Roche Holding AG 2.4 % ASML Holding N.V. 1.7 % KDDI Corp. 1.7 % UBS Group AG 1.6 % Tata Consultancy Services Ltd. 1.6 % Tencent Holdings Ltd. 1.5 % Samsung Electronics Co. Ltd. 1.5 % Sanofi 1.5 % DBS Group Holdings Ltd. 1.5 % | |
| C000160016 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Blended Research® International Equity Fund | |
| Class Name | Class R2 | |
| Trading Symbol | BRXSX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Blended Research International Equity Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R2 $ 1.14 % | |
| Expenses Paid, Amount | $ 126 | |
| Expense Ratio, Percent | 1.14% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R2 shares of the MFS Blended Research International Equity Fund (fund) provided a total return of 21.83%, at net asset value. This compares with a return of 18.21% for the fund’s benchmark, the MSCI All Country World (ex-US) Index (net div). As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI All Country World (ex-US) Index: Security selection within the information technology, consumer staples, financials and consumer discretionary sectors contributed to relative results. Top detractors from performance relative to the MSCI All Country World (ex-US) Index: Stock selection within both the materials and communication services sectors detracted from relative performance. During the reporting period, the fund's relative currency exposure, resulting primarily from differences between the fund's and the benchmark's exposures to holdings of securities denominated in foreign currencies, was another detractor from relative performance. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment* This graph shows the performance of a hypothetical $10,000 investment in Class R2 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods. Share Class 1-yr 5-yr Life* R2 without sales charge 21.83 % 9.45 % 6.72 % Comparative Benchmark(s) MSCI All Country World (ex-US) Index (net div) ∆ 18.21 % 7.56 % 6.74 % * For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024. ∆ Source: FactSet Research Systems Inc. | |
| Performance Inception Date | Sep. 15, 2015 | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r2 | |
| Net Assets | $ 709,315,854 | |
| Holdings Count | Holding | 148 | |
| Advisory Fees Paid, Amount | $ 3,239,487 | [16] |
| Investment Company Portfolio Turnover | 51% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 709,315,854 Total Management Fee ($)#: 3,239,487 Total Number of Holdings: 148 Portfolio Turnover Rate (%): 51 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 99.2 % Money Market Funds 0.8 % Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd., ADR 2.9 % Roche Holding AG 2.4 % ASML Holding N.V. 1.7 % KDDI Corp. 1.7 % UBS Group AG 1.6 % Tata Consultancy Services Ltd. 1.6 % Tencent Holdings Ltd. 1.5 % Samsung Electronics Co. Ltd. 1.5 % Sanofi 1.5 % DBS Group Holdings Ltd. 1.5 % Issuer country weightings Japan 14.8 % United Kingdom 10.4 % France 10.3 % Canada 8.7 % China 7.0 % Taiwan 4.9 % South Korea 4.8 % Switzerland 4.6 % Netherlands 4.3 % Other Countries 30.2 % | |
| Largest Holdings [Text Block] | Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd., ADR 2.9 % Roche Holding AG 2.4 % ASML Holding N.V. 1.7 % KDDI Corp. 1.7 % UBS Group AG 1.6 % Tata Consultancy Services Ltd. 1.6 % Tencent Holdings Ltd. 1.5 % Samsung Electronics Co. Ltd. 1.5 % Sanofi 1.5 % DBS Group Holdings Ltd. 1.5 % | |
| C000160017 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Blended Research® International Equity Fund | |
| Class Name | Class R3 | |
| Trading Symbol | BRXTX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Blended Research International Equity Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R3 $ 0.89 % | |
| Expenses Paid, Amount | $ 99 | |
| Expense Ratio, Percent | 0.89% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R3 shares of the MFS Blended Research International Equity Fund (fund) provided a total return of 22.08%, at net asset value. This compares with a return of 18.21% for the fund’s benchmark, the MSCI All Country World (ex-US) Index (net div). As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI All Country World (ex-US) Index: Security selection within the information technology, consumer staples, financials and consumer discretionary sectors contributed to relative results. Top detractors from performance relative to the MSCI All Country World (ex-US) Index: Stock selection within both the materials and communication services sectors detracted from relative performance. During the reporting period, the fund's relative currency exposure, resulting primarily from differences between the fund's and the benchmark's exposures to holdings of securities denominated in foreign currencies, was another detractor from relative performance. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment* This graph shows the performance of a hypothetical $10,000 investment in Class R3 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods. Share Class 1-yr 5-yr Life* R3 without sales charge 22.08 % 9.73 % 7.00 % Comparative Benchmark(s) MSCI All Country World (ex-US) Index (net div) ∆ 18.21 % 7.56 % 6.74 % * For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024. ∆ Source: FactSet Research Systems Inc. | |
| Performance Inception Date | Sep. 15, 2015 | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r3 | |
| Net Assets | $ 709,315,854 | |
| Holdings Count | Holding | 148 | |
| Advisory Fees Paid, Amount | $ 3,239,487 | [17] |
| Investment Company Portfolio Turnover | 51% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 709,315,854 Total Management Fee ($)#: 3,239,487 Total Number of Holdings: 148 Portfolio Turnover Rate (%): 51 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 99.2 % Money Market Funds 0.8 % Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd., ADR 2.9 % Roche Holding AG 2.4 % ASML Holding N.V. 1.7 % KDDI Corp. 1.7 % UBS Group AG 1.6 % Tata Consultancy Services Ltd. 1.6 % Tencent Holdings Ltd. 1.5 % Samsung Electronics Co. Ltd. 1.5 % Sanofi 1.5 % DBS Group Holdings Ltd. 1.5 % Issuer country weightings Japan 14.8 % United Kingdom 10.4 % France 10.3 % Canada 8.7 % China 7.0 % Taiwan 4.9 % South Korea 4.8 % Switzerland 4.6 % Netherlands 4.3 % Other Countries 30.2 % | |
| Largest Holdings [Text Block] | Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd., ADR 2.9 % Roche Holding AG 2.4 % ASML Holding N.V. 1.7 % KDDI Corp. 1.7 % UBS Group AG 1.6 % Tata Consultancy Services Ltd. 1.6 % Tencent Holdings Ltd. 1.5 % Samsung Electronics Co. Ltd. 1.5 % Sanofi 1.5 % DBS Group Holdings Ltd. 1.5 % | |
| C000160018 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Blended Research® International Equity Fund | |
| Class Name | Class R4 | |
| Trading Symbol | BRXUX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Blended Research International Equity Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R4 $ 0.64 % | |
| Expenses Paid, Amount | $ 71 | |
| Expense Ratio, Percent | 0.64% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R4 shares of the MFS Blended Research International Equity Fund (fund) provided a total return of 22.45%, at net asset value. This compares with a return of 18.21% for the fund’s benchmark, the MSCI All Country World (ex-US) Index (net div). As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI All Country World (ex-US) Index: Security selection within the information technology, consumer staples, financials and consumer discretionary sectors contributed to relative results. Top detractors from performance relative to the MSCI All Country World (ex-US) Index: Stock selection within both the materials and communication services sectors detracted from relative performance. During the reporting period, the fund's relative currency exposure, resulting primarily from differences between the fund's and the benchmark's exposures to holdings of securities denominated in foreign currencies, was another detractor from relative performance. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment* This graph shows the performance of a hypothetical $10,000 investment in Class R4 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods. Share Class 1-yr 5-yr Life* R4 without sales charge 22.45 % 10.02 % 7.26 % Comparative Benchmark(s) MSCI All Country World (ex-US) Index (net div) ∆ 18.21 % 7.56 % 6.74 % * For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024. ∆ Source: FactSet Research Systems Inc. | |
| Performance Inception Date | Sep. 15, 2015 | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r4 | |
| Net Assets | $ 709,315,854 | |
| Holdings Count | Holding | 148 | |
| Advisory Fees Paid, Amount | $ 3,239,487 | [18] |
| Investment Company Portfolio Turnover | 51% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 709,315,854 Total Management Fee ($)#: 3,239,487 Total Number of Holdings: 148 Portfolio Turnover Rate (%): 51 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 99.2 % Money Market Funds 0.8 % Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd., ADR 2.9 % Roche Holding AG 2.4 % ASML Holding N.V. 1.7 % KDDI Corp. 1.7 % UBS Group AG 1.6 % Tata Consultancy Services Ltd. 1.6 % Tencent Holdings Ltd. 1.5 % Samsung Electronics Co. Ltd. 1.5 % Sanofi 1.5 % DBS Group Holdings Ltd. 1.5 % Issuer country weightings Japan 14.8 % United Kingdom 10.4 % France 10.3 % Canada 8.7 % China 7.0 % Taiwan 4.9 % South Korea 4.8 % Switzerland 4.6 % Netherlands 4.3 % Other Countries 30.2 % | |
| Largest Holdings [Text Block] | Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd., ADR 2.9 % Roche Holding AG 2.4 % ASML Holding N.V. 1.7 % KDDI Corp. 1.7 % UBS Group AG 1.6 % Tata Consultancy Services Ltd. 1.6 % Tencent Holdings Ltd. 1.5 % Samsung Electronics Co. Ltd. 1.5 % Sanofi 1.5 % DBS Group Holdings Ltd. 1.5 % | |
| C000160019 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Blended Research® International Equity Fund | |
| Class Name | Class R6 | |
| Trading Symbol | BRXVX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Blended Research International Equity Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R6 $ 0.56 % | |
| Expenses Paid, Amount | $ 62 | |
| Expense Ratio, Percent | 0.56% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R6 shares of the MFS Blended Research International Equity Fund (fund) provided a total return of 22.52%, at net asset value. This compares with a return of 18.21% for the fund’s benchmark, the MSCI All Country World (ex-US) Index (net div). As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI All Country World (ex-US) Index: Security selection within the information technology, consumer staples, financials and consumer discretionary sectors contributed to relative results. Top detractors from performance relative to the MSCI All Country World (ex-US) Index: Stock selection within both the materials and communication services sectors detracted from relative performance. During the reporting period, the fund's relative currency exposure, resulting primarily from differences between the fund's and the benchmark's exposures to holdings of securities denominated in foreign currencies, was another detractor from relative performance. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment* This graph shows the performance of a hypothetical $10,000 investment in Class R6 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods. Share Class 1-yr 5-yr Life* R6 without sales charge 22.52 % 10.09 % 7.34 % Comparative Benchmark(s) MSCI All Country World (ex-US) Index (net div) ∆ 18.21 % 7.56 % 6.74 % * For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024. ∆ Source: FactSet Research Systems Inc. | |
| Performance Inception Date | Sep. 15, 2015 | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r6 | |
| Net Assets | $ 709,315,854 | |
| Holdings Count | Holding | 148 | |
| Advisory Fees Paid, Amount | $ 3,239,487 | [19] |
| Investment Company Portfolio Turnover | 51% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 709,315,854 Total Management Fee ($)#: 3,239,487 Total Number of Holdings: 148 Portfolio Turnover Rate (%): 51 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 99.2 % Money Market Funds 0.8 % Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd., ADR 2.9 % Roche Holding AG 2.4 % ASML Holding N.V. 1.7 % KDDI Corp. 1.7 % UBS Group AG 1.6 % Tata Consultancy Services Ltd. 1.6 % Tencent Holdings Ltd. 1.5 % Samsung Electronics Co. Ltd. 1.5 % Sanofi 1.5 % DBS Group Holdings Ltd. 1.5 % Issuer country weightings Japan 14.8 % United Kingdom 10.4 % France 10.3 % Canada 8.7 % China 7.0 % Taiwan 4.9 % South Korea 4.8 % Switzerland 4.6 % Netherlands 4.3 % Other Countries 30.2 % | |
| Largest Holdings [Text Block] | Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd., ADR 2.9 % Roche Holding AG 2.4 % ASML Holding N.V. 1.7 % KDDI Corp. 1.7 % UBS Group AG 1.6 % Tata Consultancy Services Ltd. 1.6 % Tencent Holdings Ltd. 1.5 % Samsung Electronics Co. Ltd. 1.5 % Sanofi 1.5 % DBS Group Holdings Ltd. 1.5 % | |
| C000006504 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Mid Cap Growth Fund | |
| Class Name | Class A | |
| Trading Symbol | OTCAX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Mid Cap Growth Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment A $ 1.02 % | |
| Expenses Paid, Amount | $ 111 | |
| Expense Ratio, Percent | 1.02% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class A shares of the MFS Mid Cap Growth Fund (fund) provided a total return of 17.94%, at net asset value. This compares with a return of 26.14% for the fund’s benchmark, the Russell 3000 ® ® As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the Russell Midcap ® Stock selection within both the information technology and industrials sectors contributed to relative performance. Top detractors from performance relative to the Russell Midcap ® Stock selection within the financials, real estate, and health care sectors weakened relative returns. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment This graph shows the performance of a hypothetical $10,000 investment in Class A over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods. Share Class 1-yr 5-yr 10-yr A without sales charge 17.94 % 9.07 % 11.13 % A with initial sales charge (5.75%) 11.16 % 7.78 % 10.47 % Comparative Benchmark(s) Russell 3000 ® 26.14 % 15.19 % 12.36 % Russell Midcap ® 19.07 % 10.50 % 10.61 % + Effective May 1, 2024, the Russell 3000 ® ® ® ∆ Source: FactSet Research Systems Inc. | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Performance Table Market Index Changed [Text Block] | Effective May 1, 2024, the Russell 3000 ® ® ® | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/a | |
| Net Assets | $ 14,721,218,721 | |
| Holdings Count | Holding | 91 | |
| Advisory Fees Paid, Amount | $ 85,839,323 | [20] |
| Investment Company Portfolio Turnover | 35% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 14,721,218,721 Total Management Fee ($)#: 85,839,323 Total Number of Holdings: 91 Portfolio Turnover Rate (%): 35 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 97.1 % Money Market Funds 2.9 % Equity sectors Industrials 23.4 % Information Technology 21.8 % Health Care 14.6 % Consumer Discretionary 11.4 % Financials 10.9 % Communication Services 5.9 % Energy 3.1 % Materials 2.1 % Consumer Staples 1.9 % Real Estate 1.6 % Utilities 0.4 % Top ten holdings Monolithic Power Systems, Inc. 3.5 % Howmet Aerospace, Inc. 3.4 % Take-Two Interactive Software, Inc. 2.2 % Bright Horizons Family Solutions, Inc. 2.2 % Verisk Analytics, Inc., "A" 2.2 % MSCI, Inc. 2.2 % Tyler Technologies, Inc. 2.2 % Gartner, Inc. 2.2 % Spotify Technology S.A. 2.1 % Wolters Kluwer N.V. 2.1 % MFS uses the Global Industry Classification Standard (GICS ® | |
| Largest Holdings [Text Block] | Top ten holdings Monolithic Power Systems, Inc. 3.5 % Howmet Aerospace, Inc. 3.4 % Take-Two Interactive Software, Inc. 2.2 % Bright Horizons Family Solutions, Inc. 2.2 % Verisk Analytics, Inc., "A" 2.2 % MSCI, Inc. 2.2 % Tyler Technologies, Inc. 2.2 % Gartner, Inc. 2.2 % Spotify Technology S.A. 2.1 % Wolters Kluwer N.V. 2.1 % | |
| C000006509 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Mid Cap Growth Fund | |
| Class Name | Class B | |
| Trading Symbol | OTCBX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Mid Cap Growth Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment B $ 1.77 % | |
| Expenses Paid, Amount | $ 192 | |
| Expense Ratio, Percent | 1.77% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class B shares of the MFS Mid Cap Growth Fund (fund) provided a total return of 17.03%, at net asset value. This compares with a return of 26.14% for the fund’s benchmark, the Russell 3000 ® ® As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the Russell Midcap ® Stock selection within both the information technology and industrials sectors contributed to relative performance. Top detractors from performance relative to the Russell Midcap ® Stock selection within the financials, real estate, and health care sectors weakened relative returns. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment This graph shows the performance of a hypothetical $10,000 investment in Class B over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods. Share Class 1-yr 5-yr 10-yr B without sales charge 17.03 % 8.25 % 10.30 % B with CDSC (declining over six years from 4% to 0%) × 13.03 % 7.96 % 10.30 % Comparative Benchmark(s) Russell 3000 ® 26.14 % 15.19 % 12.36 % Russell Midcap ® 19.07 % 10.50 % 10.61 % + Effective May 1, 2024, the Russell 3000 ® ® ® ∆ Source: FactSet Research Systems Inc. × Assuming redemption at the end of the applicable period. | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Performance Table Market Index Changed [Text Block] | Effective May 1, 2024, the Russell 3000 ® ® ® | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/b | |
| Net Assets | $ 14,721,218,721 | |
| Holdings Count | Holding | 91 | |
| Advisory Fees Paid, Amount | $ 85,839,323 | [21] |
| Investment Company Portfolio Turnover | 35% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 14,721,218,721 Total Management Fee ($)#: 85,839,323 Total Number of Holdings: 91 Portfolio Turnover Rate (%): 35 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 97.1 % Money Market Funds 2.9 % Equity sectors Industrials 23.4 % Information Technology 21.8 % Health Care 14.6 % Consumer Discretionary 11.4 % Financials 10.9 % Communication Services 5.9 % Energy 3.1 % Materials 2.1 % Consumer Staples 1.9 % Real Estate 1.6 % Utilities 0.4 % Top ten holdings Monolithic Power Systems, Inc. 3.5 % Howmet Aerospace, Inc. 3.4 % Take-Two Interactive Software, Inc. 2.2 % Bright Horizons Family Solutions, Inc. 2.2 % Verisk Analytics, Inc., "A" 2.2 % MSCI, Inc. 2.2 % Tyler Technologies, Inc. 2.2 % Gartner, Inc. 2.2 % Spotify Technology S.A. 2.1 % Wolters Kluwer N.V. 2.1 % MFS uses the Global Industry Classification Standard (GICS ® | |
| Largest Holdings [Text Block] | Top ten holdings Monolithic Power Systems, Inc. 3.5 % Howmet Aerospace, Inc. 3.4 % Take-Two Interactive Software, Inc. 2.2 % Bright Horizons Family Solutions, Inc. 2.2 % Verisk Analytics, Inc., "A" 2.2 % MSCI, Inc. 2.2 % Tyler Technologies, Inc. 2.2 % Gartner, Inc. 2.2 % Spotify Technology S.A. 2.1 % Wolters Kluwer N.V. 2.1 % | |
| C000006510 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Mid Cap Growth Fund | |
| Class Name | Class C | |
| Trading Symbol | OTCCX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Mid Cap Growth Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment C $ 1.77 % | |
| Expenses Paid, Amount | $ 192 | |
| Expense Ratio, Percent | 1.77% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class C shares of the MFS Mid Cap Growth Fund (fund) provided a total return of 17.05%, at net asset value. This compares with a return of 26.14% for the fund’s benchmark, the Russell 3000 ® ® As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the Russell Midcap ® Stock selection within both the information technology and industrials sectors contributed to relative performance. Top detractors from performance relative to the Russell Midcap ® Stock selection within the financials, real estate, and health care sectors weakened relative returns. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment This graph shows the performance of a hypothetical $10,000 investment in Class C over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods. Share Class 1-yr 5-yr 10-yr C without sales charge 17.05 % 8.25 % 10.30 % C with CDSC (1% for 12 months) × 16.05 % 8.25 % 10.30 % Comparative Benchmark(s) Russell 3000 ® 26.14 % 15.19 % 12.36 % Russell Midcap ® 19.07 % 10.50 % 10.61 % + Effective May 1, 2024, the Russell 3000 ® ® ® ∆ Source: FactSet Research Systems Inc. × Assuming redemption at the end of the applicable period. | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Performance Table Market Index Changed [Text Block] | Effective May 1, 2024, the Russell 3000 ® ® ® | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/c | |
| Net Assets | $ 14,721,218,721 | |
| Holdings Count | Holding | 91 | |
| Advisory Fees Paid, Amount | $ 85,839,323 | [22] |
| Investment Company Portfolio Turnover | 35% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 14,721,218,721 Total Management Fee ($)#: 85,839,323 Total Number of Holdings: 91 Portfolio Turnover Rate (%): 35 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 97.1 % Money Market Funds 2.9 % Equity sectors Industrials 23.4 % Information Technology 21.8 % Health Care 14.6 % Consumer Discretionary 11.4 % Financials 10.9 % Communication Services 5.9 % Energy 3.1 % Materials 2.1 % Consumer Staples 1.9 % Real Estate 1.6 % Utilities 0.4 % Top ten holdings Monolithic Power Systems, Inc. 3.5 % Howmet Aerospace, Inc. 3.4 % Take-Two Interactive Software, Inc. 2.2 % Bright Horizons Family Solutions, Inc. 2.2 % Verisk Analytics, Inc., "A" 2.2 % MSCI, Inc. 2.2 % Tyler Technologies, Inc. 2.2 % Gartner, Inc. 2.2 % Spotify Technology S.A. 2.1 % Wolters Kluwer N.V. 2.1 % MFS uses the Global Industry Classification Standard (GICS ® | |
| Largest Holdings [Text Block] | Top ten holdings Monolithic Power Systems, Inc. 3.5 % Howmet Aerospace, Inc. 3.4 % Take-Two Interactive Software, Inc. 2.2 % Bright Horizons Family Solutions, Inc. 2.2 % Verisk Analytics, Inc., "A" 2.2 % MSCI, Inc. 2.2 % Tyler Technologies, Inc. 2.2 % Gartner, Inc. 2.2 % Spotify Technology S.A. 2.1 % Wolters Kluwer N.V. 2.1 % | |
| C000006511 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Mid Cap Growth Fund | |
| Class Name | Class I | |
| Trading Symbol | OTCIX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Mid Cap Growth Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment I $ 0.77 % | |
| Expenses Paid, Amount | $ 84 | |
| Expense Ratio, Percent | 0.77% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class I shares of the MFS Mid Cap Growth Fund (fund) provided a total return of 18.19%, at net asset value. This compares with a return of 26.14% for the fund’s benchmark, the Russell 3000 ® ® As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the Russell Midcap ® Stock selection within both the information technology and industrials sectors contributed to relative performance. Top detractors from performance relative to the Russell Midcap ® Stock selection within the financials, real estate, and health care sectors weakened relative returns. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment This graph shows the performance of a hypothetical $10,000 investment in Class I over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods. Share Class 1-yr 5-yr 10-yr I without sales charge 18.19 % 9.33 % 11.40 % Comparative Benchmark(s) Russell 3000 ® 26.14 % 15.19 % 12.36 % Russell Midcap ® 19.07 % 10.50 % 10.61 % + Effective May 1, 2024, the Russell 3000 ® ® ® ∆ Source: FactSet Research Systems Inc. | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Performance Table Market Index Changed [Text Block] | Effective May 1, 2024, the Russell 3000 ® ® ® | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/i | |
| Net Assets | $ 14,721,218,721 | |
| Holdings Count | Holding | 91 | |
| Advisory Fees Paid, Amount | $ 85,839,323 | [23] |
| Investment Company Portfolio Turnover | 35% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 14,721,218,721 Total Management Fee ($)#: 85,839,323 Total Number of Holdings: 91 Portfolio Turnover Rate (%): 35 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 97.1 % Money Market Funds 2.9 % Equity sectors Industrials 23.4 % Information Technology 21.8 % Health Care 14.6 % Consumer Discretionary 11.4 % Financials 10.9 % Communication Services 5.9 % Energy 3.1 % Materials 2.1 % Consumer Staples 1.9 % Real Estate 1.6 % Utilities 0.4 % Top ten holdings Monolithic Power Systems, Inc. 3.5 % Howmet Aerospace, Inc. 3.4 % Take-Two Interactive Software, Inc. 2.2 % Bright Horizons Family Solutions, Inc. 2.2 % Verisk Analytics, Inc., "A" 2.2 % MSCI, Inc. 2.2 % Tyler Technologies, Inc. 2.2 % Gartner, Inc. 2.2 % Spotify Technology S.A. 2.1 % Wolters Kluwer N.V. 2.1 % MFS uses the Global Industry Classification Standard (GICS ® | |
| Largest Holdings [Text Block] | Top ten holdings Monolithic Power Systems, Inc. 3.5 % Howmet Aerospace, Inc. 3.4 % Take-Two Interactive Software, Inc. 2.2 % Bright Horizons Family Solutions, Inc. 2.2 % Verisk Analytics, Inc., "A" 2.2 % MSCI, Inc. 2.2 % Tyler Technologies, Inc. 2.2 % Gartner, Inc. 2.2 % Spotify Technology S.A. 2.1 % Wolters Kluwer N.V. 2.1 % | |
| C000006513 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Mid Cap Growth Fund | |
| Class Name | Class R1 | |
| Trading Symbol | OTCGX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Mid Cap Growth Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R1 $ 1.77 % | |
| Expenses Paid, Amount | $ 192 | |
| Expense Ratio, Percent | 1.77% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R1 shares of the MFS Mid Cap Growth Fund (fund) provided a total return of 17.03%, at net asset value. This compares with a return of 26.14% for the fund’s benchmark, the Russell 3000 ® ® As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the Russell Midcap ® Stock selection within both the information technology and industrials sectors contributed to relative performance. Top detractors from performance relative to the Russell Midcap ® Stock selection within the financials, real estate, and health care sectors weakened relative returns. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment This graph shows the performance of a hypothetical $10,000 investment in Class R1 over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods. Share Class 1-yr 5-yr 10-yr R1 without sales charge 17.03 % 8.24 % 10.30 % Comparative Benchmark(s) Russell 3000 ® 26.14 % 15.19 % 12.36 % Russell Midcap ® 19.07 % 10.50 % 10.61 % + Effective May 1, 2024, the Russell 3000 ® ® ® ∆ Source: FactSet Research Systems Inc. | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Performance Table Market Index Changed [Text Block] | Effective May 1, 2024, the Russell 3000 ® ® ® | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r1 | |
| Net Assets | $ 14,721,218,721 | |
| Holdings Count | Holding | 91 | |
| Advisory Fees Paid, Amount | $ 85,839,323 | [24] |
| Investment Company Portfolio Turnover | 35% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 14,721,218,721 Total Management Fee ($)#: 85,839,323 Total Number of Holdings: 91 Portfolio Turnover Rate (%): 35 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 97.1 % Money Market Funds 2.9 % Equity sectors Industrials 23.4 % Information Technology 21.8 % Health Care 14.6 % Consumer Discretionary 11.4 % Financials 10.9 % Communication Services 5.9 % Energy 3.1 % Materials 2.1 % Consumer Staples 1.9 % Real Estate 1.6 % Utilities 0.4 % Top ten holdings Monolithic Power Systems, Inc. 3.5 % Howmet Aerospace, Inc. 3.4 % Take-Two Interactive Software, Inc. 2.2 % Bright Horizons Family Solutions, Inc. 2.2 % Verisk Analytics, Inc., "A" 2.2 % MSCI, Inc. 2.2 % Tyler Technologies, Inc. 2.2 % Gartner, Inc. 2.2 % Spotify Technology S.A. 2.1 % Wolters Kluwer N.V. 2.1 % MFS uses the Global Industry Classification Standard (GICS ® | |
| Largest Holdings [Text Block] | Top ten holdings Monolithic Power Systems, Inc. 3.5 % Howmet Aerospace, Inc. 3.4 % Take-Two Interactive Software, Inc. 2.2 % Bright Horizons Family Solutions, Inc. 2.2 % Verisk Analytics, Inc., "A" 2.2 % MSCI, Inc. 2.2 % Tyler Technologies, Inc. 2.2 % Gartner, Inc. 2.2 % Spotify Technology S.A. 2.1 % Wolters Kluwer N.V. 2.1 % | |
| C000006515 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Mid Cap Growth Fund | |
| Class Name | Class R2 | |
| Trading Symbol | MCPRX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Mid Cap Growth Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R2 $ 1.27 % | |
| Expenses Paid, Amount | $ 138 | |
| Expense Ratio, Percent | 1.27% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R2 shares of the MFS Mid Cap Growth Fund (fund) provided a total return of 17.61%, at net asset value. This compares with a return of 26.14% for the fund’s benchmark, the Russell 3000 ® ® As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the Russell Midcap ® Stock selection within both the information technology and industrials sectors contributed to relative performance. Top detractors from performance relative to the Russell Midcap ® Stock selection within the financials, real estate, and health care sectors weakened relative returns. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment This graph shows the performance of a hypothetical $10,000 investment in Class R2 over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods. Share Class 1-yr 5-yr 10-yr R2 without sales charge 17.61 % 8.79 % 10.85 % Comparative Benchmark(s) Russell 3000 ® 26.14 % 15.19 % 12.36 % Russell Midcap ® 19.07 % 10.50 % 10.61 % + Effective May 1, 2024, the Russell 3000 ® ® ® ∆ Source: FactSet Research Systems Inc. | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Performance Table Market Index Changed [Text Block] | Effective May 1, 2024, the Russell 3000 ® ® ® | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r2 | |
| Net Assets | $ 14,721,218,721 | |
| Holdings Count | Holding | 91 | |
| Advisory Fees Paid, Amount | $ 85,839,323 | [25] |
| Investment Company Portfolio Turnover | 35% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 14,721,218,721 Total Management Fee ($)#: 85,839,323 Total Number of Holdings: 91 Portfolio Turnover Rate (%): 35 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 97.1 % Money Market Funds 2.9 % Equity sectors Industrials 23.4 % Information Technology 21.8 % Health Care 14.6 % Consumer Discretionary 11.4 % Financials 10.9 % Communication Services 5.9 % Energy 3.1 % Materials 2.1 % Consumer Staples 1.9 % Real Estate 1.6 % Utilities 0.4 % Top ten holdings Monolithic Power Systems, Inc. 3.5 % Howmet Aerospace, Inc. 3.4 % Take-Two Interactive Software, Inc. 2.2 % Bright Horizons Family Solutions, Inc. 2.2 % Verisk Analytics, Inc., "A" 2.2 % MSCI, Inc. 2.2 % Tyler Technologies, Inc. 2.2 % Gartner, Inc. 2.2 % Spotify Technology S.A. 2.1 % Wolters Kluwer N.V. 2.1 % MFS uses the Global Industry Classification Standard (GICS ® | |
| Largest Holdings [Text Block] | Top ten holdings Monolithic Power Systems, Inc. 3.5 % Howmet Aerospace, Inc. 3.4 % Take-Two Interactive Software, Inc. 2.2 % Bright Horizons Family Solutions, Inc. 2.2 % Verisk Analytics, Inc., "A" 2.2 % MSCI, Inc. 2.2 % Tyler Technologies, Inc. 2.2 % Gartner, Inc. 2.2 % Spotify Technology S.A. 2.1 % Wolters Kluwer N.V. 2.1 % | |
| C000006516 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Mid Cap Growth Fund | |
| Class Name | Class R3 | |
| Trading Symbol | OTCHX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Mid Cap Growth Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R3 $ 1.02 % | |
| Expenses Paid, Amount | $ 111 | |
| Expense Ratio, Percent | 1.02% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R3 shares of the MFS Mid Cap Growth Fund (fund) provided a total return of 17.94%, at net asset value. This compares with a return of 26.14% for the fund’s benchmark, the Russell 3000 ® ® As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the Russell Midcap ® Stock selection within both the information technology and industrials sectors contributed to relative performance. Top detractors from performance relative to the Russell Midcap ® Stock selection within the financials, real estate, and health care sectors weakened relative returns. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment This graph shows the performance of a hypothetical $10,000 investment in Class R3 over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods. Share Class 1-yr 5-yr 10-yr R3 without sales charge 17.94 % 9.07 % 11.13 % Comparative Benchmark(s) Russell 3000 ® 26.14 % 15.19 % 12.36 % Russell Midcap ® 19.07 % 10.50 % 10.61 % + Effective May 1, 2024, the Russell 3000 ® ® ® ∆ Source: FactSet Research Systems Inc. | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Performance Table Market Index Changed [Text Block] | Effective May 1, 2024, the Russell 3000 ® ® ® | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r3 | |
| Net Assets | $ 14,721,218,721 | |
| Holdings Count | Holding | 91 | |
| Advisory Fees Paid, Amount | $ 85,839,323 | [26] |
| Investment Company Portfolio Turnover | 35% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 14,721,218,721 Total Management Fee ($)#: 85,839,323 Total Number of Holdings: 91 Portfolio Turnover Rate (%): 35 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 97.1 % Money Market Funds 2.9 % Equity sectors Industrials 23.4 % Information Technology 21.8 % Health Care 14.6 % Consumer Discretionary 11.4 % Financials 10.9 % Communication Services 5.9 % Energy 3.1 % Materials 2.1 % Consumer Staples 1.9 % Real Estate 1.6 % Utilities 0.4 % Top ten holdings Monolithic Power Systems, Inc. 3.5 % Howmet Aerospace, Inc. 3.4 % Take-Two Interactive Software, Inc. 2.2 % Bright Horizons Family Solutions, Inc. 2.2 % Verisk Analytics, Inc., "A" 2.2 % MSCI, Inc. 2.2 % Tyler Technologies, Inc. 2.2 % Gartner, Inc. 2.2 % Spotify Technology S.A. 2.1 % Wolters Kluwer N.V. 2.1 % MFS uses the Global Industry Classification Standard (GICS ® | |
| Largest Holdings [Text Block] | Top ten holdings Monolithic Power Systems, Inc. 3.5 % Howmet Aerospace, Inc. 3.4 % Take-Two Interactive Software, Inc. 2.2 % Bright Horizons Family Solutions, Inc. 2.2 % Verisk Analytics, Inc., "A" 2.2 % MSCI, Inc. 2.2 % Tyler Technologies, Inc. 2.2 % Gartner, Inc. 2.2 % Spotify Technology S.A. 2.1 % Wolters Kluwer N.V. 2.1 % | |
| C000006505 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Mid Cap Growth Fund | |
| Class Name | Class R4 | |
| Trading Symbol | OTCJX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Mid Cap Growth Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R4 $ 0.77 % | |
| Expenses Paid, Amount | $ 84 | |
| Expense Ratio, Percent | 0.77% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R4 shares of the MFS Mid Cap Growth Fund (fund) provided a total return of 18.20%, at net asset value. This compares with a return of 26.14% for the fund’s benchmark, the Russell 3000 ® ® As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the Russell Midcap ® Stock selection within both the information technology and industrials sectors contributed to relative performance. Top detractors from performance relative to the Russell Midcap ® Stock selection within the financials, real estate, and health care sectors weakened relative returns. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment This graph shows the performance of a hypothetical $10,000 investment in Class R4 over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods. Share Class 1-yr 5-yr 10-yr R4 without sales charge 18.20 % 9.34 % 11.40 % Comparative Benchmark(s) Russell 3000 ® 26.14 % 15.19 % 12.36 % Russell Midcap ® 19.07 % 10.50 % 10.61 % + Effective May 1, 2024, the Russell 3000 ® ® ® ∆ Source: FactSet Research Systems Inc. | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Performance Table Market Index Changed [Text Block] | Effective May 1, 2024, the Russell 3000 ® ® ® | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r4 | |
| Net Assets | $ 14,721,218,721 | |
| Holdings Count | Holding | 91 | |
| Advisory Fees Paid, Amount | $ 85,839,323 | [27] |
| Investment Company Portfolio Turnover | 35% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 14,721,218,721 Total Management Fee ($)#: 85,839,323 Total Number of Holdings: 91 Portfolio Turnover Rate (%): 35 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 97.1 % Money Market Funds 2.9 % Equity sectors Industrials 23.4 % Information Technology 21.8 % Health Care 14.6 % Consumer Discretionary 11.4 % Financials 10.9 % Communication Services 5.9 % Energy 3.1 % Materials 2.1 % Consumer Staples 1.9 % Real Estate 1.6 % Utilities 0.4 % Top ten holdings Monolithic Power Systems, Inc. 3.5 % Howmet Aerospace, Inc. 3.4 % Take-Two Interactive Software, Inc. 2.2 % Bright Horizons Family Solutions, Inc. 2.2 % Verisk Analytics, Inc., "A" 2.2 % MSCI, Inc. 2.2 % Tyler Technologies, Inc. 2.2 % Gartner, Inc. 2.2 % Spotify Technology S.A. 2.1 % Wolters Kluwer N.V. 2.1 % MFS uses the Global Industry Classification Standard (GICS ® | |
| Largest Holdings [Text Block] | Top ten holdings Monolithic Power Systems, Inc. 3.5 % Howmet Aerospace, Inc. 3.4 % Take-Two Interactive Software, Inc. 2.2 % Bright Horizons Family Solutions, Inc. 2.2 % Verisk Analytics, Inc., "A" 2.2 % MSCI, Inc. 2.2 % Tyler Technologies, Inc. 2.2 % Gartner, Inc. 2.2 % Spotify Technology S.A. 2.1 % Wolters Kluwer N.V. 2.1 % | |
| C000124428 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Mid Cap Growth Fund | |
| Class Name | Class R6 | |
| Trading Symbol | OTCKX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Mid Cap Growth Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R6 $ 0.65 % | |
| Expenses Paid, Amount | $ 71 | |
| Expense Ratio, Percent | 0.65% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R6 shares of the MFS Mid Cap Growth Fund (fund) provided a total return of 18.34%, at net asset value. This compares with a return of 26.14% for the fund’s benchmark, the Russell 3000 ® ® As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the Russell Midcap ® Stock selection within both the information technology and industrials sectors contributed to relative performance. Top detractors from performance relative to the Russell Midcap ® Stock selection within the financials, real estate, and health care sectors weakened relative returns. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment This graph shows the performance of a hypothetical $10,000 investment in Class R6 over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods. Share Class 1-yr 5-yr 10-yr R6 without sales charge 18.34 % 9.46 % 11.52 % Comparative Benchmark(s) Russell 3000 ® 26.14 % 15.19 % 12.36 % Russell Midcap ® 19.07 % 10.50 % 10.61 % + Effective May 1, 2024, the Russell 3000 ® ® ® ∆ Source: FactSet Research Systems Inc. | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Performance Table Market Index Changed [Text Block] | Effective May 1, 2024, the Russell 3000 ® ® ® | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r6 | |
| Net Assets | $ 14,721,218,721 | |
| Holdings Count | Holding | 91 | |
| Advisory Fees Paid, Amount | $ 85,839,323 | [28] |
| Investment Company Portfolio Turnover | 35% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 14,721,218,721 Total Management Fee ($)#: 85,839,323 Total Number of Holdings: 91 Portfolio Turnover Rate (%): 35 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 97.1 % Money Market Funds 2.9 % Equity sectors Industrials 23.4 % Information Technology 21.8 % Health Care 14.6 % Consumer Discretionary 11.4 % Financials 10.9 % Communication Services 5.9 % Energy 3.1 % Materials 2.1 % Consumer Staples 1.9 % Real Estate 1.6 % Utilities 0.4 % Top ten holdings Monolithic Power Systems, Inc. 3.5 % Howmet Aerospace, Inc. 3.4 % Take-Two Interactive Software, Inc. 2.2 % Bright Horizons Family Solutions, Inc. 2.2 % Verisk Analytics, Inc., "A" 2.2 % MSCI, Inc. 2.2 % Tyler Technologies, Inc. 2.2 % Gartner, Inc. 2.2 % Spotify Technology S.A. 2.1 % Wolters Kluwer N.V. 2.1 % MFS uses the Global Industry Classification Standard (GICS ® | |
| Largest Holdings [Text Block] | Top ten holdings Monolithic Power Systems, Inc. 3.5 % Howmet Aerospace, Inc. 3.4 % Take-Two Interactive Software, Inc. 2.2 % Bright Horizons Family Solutions, Inc. 2.2 % Verisk Analytics, Inc., "A" 2.2 % MSCI, Inc. 2.2 % Tyler Technologies, Inc. 2.2 % Gartner, Inc. 2.2 % Spotify Technology S.A. 2.1 % Wolters Kluwer N.V. 2.1 % | |
| C000159993 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Blended Research® Emerging Markets Equity Fund | |
| Class Name | Class A | |
| Trading Symbol | BRKAX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Blended Research Emerging Markets Equity Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment A $ 1.24 % | |
| Expenses Paid, Amount | $ 136 | |
| Expense Ratio, Percent | 1.24% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class A shares of the MFS Blended Research Emerging Markets Equity Fund (fund) provided a total return of 18.72%, at net asset value. This compares with a return of 15.07% for the fund’s benchmark, the MSCI Emerging Markets Index (net div). As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI Emerging Markets Index: Security selection within both the information technology and financials sectors contributed to relative performance. Top detractors from performance relative to the MSCI Emerging Markets Index: Weak stock selection within the communication services sector held back relative results. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment* This graph shows the performance of a hypothetical $10,000 investment in Class A over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods. Share Class 1-yr 5-yr Life* A without sales charge 18.72 % 5.59 % 6.63 % A with initial sales charge (5.75%) 11.90 % 4.35 % 5.92 % Comparative Benchmark(s) MSCI Emerging Markets Index (net div) ∆ 15.07 % 4.79 % 6.03 % * For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024. ∆ Source: FactSet Research Systems Inc. | |
| Performance Inception Date | Sep. 15, 2015 | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/a | |
| Net Assets | $ 91,229,346 | |
| Holdings Count | Holding | 137 | |
| Advisory Fees Paid, Amount | $ 471,631 | [29] |
| Investment Company Portfolio Turnover | 58% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 91,229,346 Total Management Fee ($)#: 471,631 Total Number of Holdings: 137 Portfolio Turnover Rate (%): 58 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 98.4 % Money Market Funds 1.6 % Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd. 10.0 % Tencent Holdings Ltd. 4.6 % Samsung Electronics Co. Ltd. 4.4 % Hon Hai Precision Industry Co. Ltd. 2.1 % China Construction Bank Corp. 2.1 % Tata Consultancy Services Ltd. 2.0 % Alibaba Group Holding Ltd. 1.8 % Mahindra & Mahindra Ltd. 1.7 % Petrobras 1.7 % Infosys Ltd. 1.4 % Issuer country weightings China 24.7 % India 18.6 % Taiwan 15.8 % South Korea 13.9 % Brazil 5.4 % Indonesia 3.3 % United Arab Emirates 2.9 % Greece 2.2 % Mexico 2.0 % Other Countries 11.2 % | |
| Largest Holdings [Text Block] | Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd. 10.0 % Tencent Holdings Ltd. 4.6 % Samsung Electronics Co. Ltd. 4.4 % Hon Hai Precision Industry Co. Ltd. 2.1 % China Construction Bank Corp. 2.1 % Tata Consultancy Services Ltd. 2.0 % Alibaba Group Holding Ltd. 1.8 % Mahindra & Mahindra Ltd. 1.7 % Petrobras 1.7 % Infosys Ltd. 1.4 % | |
| C000159994 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Blended Research® Emerging Markets Equity Fund | |
| Class Name | Class B | |
| Trading Symbol | BRKBX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Blended Research Emerging Markets Equity Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment B $ 1.99 % | |
| Expenses Paid, Amount | $ 217 | |
| Expense Ratio, Percent | 1.99% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class B shares of the MFS Blended Research Emerging Markets Equity Fund (fund) provided a total return of 17.80%, at net asset value. This compares with a return of 15.07% for the fund’s benchmark, the MSCI Emerging Markets Index (net div). As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI Emerging Markets Index: Security selection within both the information technology and financials sectors contributed to relative performance. Top detractors from performance relative to the MSCI Emerging Markets Index: Weak stock selection within the communication services sector held back relative results. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment* This graph shows the performance of a hypothetical $10,000 investment in Class B over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods. Share Class 1-yr 5-yr Life* B without sales charge 17.80 % 4.81 % 5.83 % B with CDSC (declining over six years from 4% to 0%) × 13.80 % 4.48 % 5.83 % Comparative Benchmark(s) MSCI Emerging Markets Index (net div) ∆ 15.07 % 4.79 % 6.03 % * For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024. ∆ Source: FactSet Research Systems Inc. × Assuming redemption at the end of the applicable period. | |
| Performance Inception Date | Sep. 15, 2015 | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/b | |
| Net Assets | $ 91,229,346 | |
| Holdings Count | Holding | 137 | |
| Advisory Fees Paid, Amount | $ 471,631 | [30] |
| Investment Company Portfolio Turnover | 58% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 91,229,346 Total Management Fee ($)#: 471,631 Total Number of Holdings: 137 Portfolio Turnover Rate (%): 58 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 98.4 % Money Market Funds 1.6 % Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd. 10.0 % Tencent Holdings Ltd. 4.6 % Samsung Electronics Co. Ltd. 4.4 % Hon Hai Precision Industry Co. Ltd. 2.1 % China Construction Bank Corp. 2.1 % Tata Consultancy Services Ltd. 2.0 % Alibaba Group Holding Ltd. 1.8 % Mahindra & Mahindra Ltd. 1.7 % Petrobras 1.7 % Infosys Ltd. 1.4 % Issuer country weightings China 24.7 % India 18.6 % Taiwan 15.8 % South Korea 13.9 % Brazil 5.4 % Indonesia 3.3 % United Arab Emirates 2.9 % Greece 2.2 % Mexico 2.0 % Other Countries 11.2 % | |
| Largest Holdings [Text Block] | Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd. 10.0 % Tencent Holdings Ltd. 4.6 % Samsung Electronics Co. Ltd. 4.4 % Hon Hai Precision Industry Co. Ltd. 2.1 % China Construction Bank Corp. 2.1 % Tata Consultancy Services Ltd. 2.0 % Alibaba Group Holding Ltd. 1.8 % Mahindra & Mahindra Ltd. 1.7 % Petrobras 1.7 % Infosys Ltd. 1.4 % | |
| C000159995 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Blended Research® Emerging Markets Equity Fund | |
| Class Name | Class C | |
| Trading Symbol | BRKCX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Blended Research Emerging Markets Equity Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment C $ 1.99 % | |
| Expenses Paid, Amount | $ 217 | |
| Expense Ratio, Percent | 1.99% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class C shares of the MFS Blended Research Emerging Markets Equity Fund (fund) provided a total return of 17.79%, at net asset value. This compares with a return of 15.07% for the fund’s benchmark, the MSCI Emerging Markets Index (net div). As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI Emerging Markets Index: Security selection within both the information technology and financials sectors contributed to relative performance. Top detractors from performance relative to the MSCI Emerging Markets Index: Weak stock selection within the communication services sector held back relative results. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment* This graph shows the performance of a hypothetical $10,000 investment in Class C over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods. Share Class 1-yr 5-yr Life* C without sales charge 17.79 % 4.80 % 5.83 % C with CDSC (1% for 12 months) × 16.79 % 4.80 % 5.83 % Comparative Benchmark(s) MSCI Emerging Markets Index (net div) ∆ 15.07 % 4.79 % 6.03 % * For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024. ∆ Source: FactSet Research Systems Inc. × Assuming redemption at the end of the applicable period. | |
| Performance Inception Date | Sep. 15, 2015 | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/c | |
| Net Assets | $ 91,229,346 | |
| Holdings Count | Holding | 137 | |
| Advisory Fees Paid, Amount | $ 471,631 | [31] |
| Investment Company Portfolio Turnover | 58% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 91,229,346 Total Management Fee ($)#: 471,631 Total Number of Holdings: 137 Portfolio Turnover Rate (%): 58 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 98.4 % Money Market Funds 1.6 % Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd. 10.0 % Tencent Holdings Ltd. 4.6 % Samsung Electronics Co. Ltd. 4.4 % Hon Hai Precision Industry Co. Ltd. 2.1 % China Construction Bank Corp. 2.1 % Tata Consultancy Services Ltd. 2.0 % Alibaba Group Holding Ltd. 1.8 % Mahindra & Mahindra Ltd. 1.7 % Petrobras 1.7 % Infosys Ltd. 1.4 % Issuer country weightings China 24.7 % India 18.6 % Taiwan 15.8 % South Korea 13.9 % Brazil 5.4 % Indonesia 3.3 % United Arab Emirates 2.9 % Greece 2.2 % Mexico 2.0 % Other Countries 11.2 % | |
| Largest Holdings [Text Block] | Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd. 10.0 % Tencent Holdings Ltd. 4.6 % Samsung Electronics Co. Ltd. 4.4 % Hon Hai Precision Industry Co. Ltd. 2.1 % China Construction Bank Corp. 2.1 % Tata Consultancy Services Ltd. 2.0 % Alibaba Group Holding Ltd. 1.8 % Mahindra & Mahindra Ltd. 1.7 % Petrobras 1.7 % Infosys Ltd. 1.4 % | |
| C000159996 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Blended Research® Emerging Markets Equity Fund | |
| Class Name | Class I | |
| Trading Symbol | BRKIX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Blended Research Emerging Markets Equity Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment I $ 0.99 % | |
| Expenses Paid, Amount | $ 108 | |
| Expense Ratio, Percent | 0.99% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class I shares of the MFS Blended Research Emerging Markets Equity Fund (fund) provided a total return of 19.00%, at net asset value. This compares with a return of 15.07% for the fund’s benchmark, the MSCI Emerging Markets Index (net div). As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI Emerging Markets Index: Security selection within both the information technology and financials sectors contributed to relative performance. Top detractors from performance relative to the MSCI Emerging Markets Index: Weak stock selection within the communication services sector held back relative results. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment* This graph shows the performance of a hypothetical $10,000 investment in Class I over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods. Share Class 1-yr 5-yr Life* I without sales charge 19.00 % 5.85 % 6.89 % Comparative Benchmark(s) MSCI Emerging Markets Index (net div) ∆ 15.07 % 4.79 % 6.03 % * For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024. ∆ Source: FactSet Research Systems Inc. | |
| Performance Inception Date | Sep. 15, 2015 | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/i | |
| Net Assets | $ 91,229,346 | |
| Holdings Count | Holding | 137 | |
| Advisory Fees Paid, Amount | $ 471,631 | [32] |
| Investment Company Portfolio Turnover | 58% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 91,229,346 Total Management Fee ($)#: 471,631 Total Number of Holdings: 137 Portfolio Turnover Rate (%): 58 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 98.4 % Money Market Funds 1.6 % Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd. 10.0 % Tencent Holdings Ltd. 4.6 % Samsung Electronics Co. Ltd. 4.4 % Hon Hai Precision Industry Co. Ltd. 2.1 % China Construction Bank Corp. 2.1 % Tata Consultancy Services Ltd. 2.0 % Alibaba Group Holding Ltd. 1.8 % Mahindra & Mahindra Ltd. 1.7 % Petrobras 1.7 % Infosys Ltd. 1.4 % Issuer country weightings China 24.7 % India 18.6 % Taiwan 15.8 % South Korea 13.9 % Brazil 5.4 % Indonesia 3.3 % United Arab Emirates 2.9 % Greece 2.2 % Mexico 2.0 % Other Countries 11.2 % | |
| Largest Holdings [Text Block] | Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd. 10.0 % Tencent Holdings Ltd. 4.6 % Samsung Electronics Co. Ltd. 4.4 % Hon Hai Precision Industry Co. Ltd. 2.1 % China Construction Bank Corp. 2.1 % Tata Consultancy Services Ltd. 2.0 % Alibaba Group Holding Ltd. 1.8 % Mahindra & Mahindra Ltd. 1.7 % Petrobras 1.7 % Infosys Ltd. 1.4 % | |
| C000159997 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Blended Research® Emerging Markets Equity Fund | |
| Class Name | Class R1 | |
| Trading Symbol | BRKRX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Blended Research Emerging Markets Equity Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R1 $ 1.24 % For the period from September 1, 2023 through August 31, 2024, the distribution fee was not imposed. Had the distribution fee been imposed throughout the entire period, the “Costs of a $10,000 investment” and the “Costs paid as a percentage of a $10,000 investment” would have been approximately $218 and 1.99%, respectively. | |
| Expenses Paid, Amount | $ 136 | |
| Expense Ratio, Percent | 1.24% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R1 shares of the MFS Blended Research Emerging Markets Equity Fund (fund) provided a total return of 18.67%, at net asset value. This compares with a return of 15.07% for the fund’s benchmark, the MSCI Emerging Markets Index (net div). As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI Emerging Markets Index: Security selection within both the information technology and financials sectors contributed to relative performance. Top detractors from performance relative to the MSCI Emerging Markets Index: Weak stock selection within the communication services sector held back relative results. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment* This graph shows the performance of a hypothetical $10,000 investment in Class R1 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods. Share Class 1-yr 5-yr Life* R1 without sales charge 18.67 % 5.35 % 6.14 % Comparative Benchmark(s) MSCI Emerging Markets Index (net div) ∆ 15.07 % 4.79 % 6.03 % * For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024. ∆ Source: FactSet Research Systems Inc. | |
| Performance Inception Date | Sep. 15, 2015 | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r1 | |
| Net Assets | $ 91,229,346 | |
| Holdings Count | Holding | 137 | |
| Advisory Fees Paid, Amount | $ 471,631 | [33] |
| Investment Company Portfolio Turnover | 58% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 91,229,346 Total Management Fee ($)#: 471,631 Total Number of Holdings: 137 Portfolio Turnover Rate (%): 58 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 98.4 % Money Market Funds 1.6 % Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd. 10.0 % Tencent Holdings Ltd. 4.6 % Samsung Electronics Co. Ltd. 4.4 % Hon Hai Precision Industry Co. Ltd. 2.1 % China Construction Bank Corp. 2.1 % Tata Consultancy Services Ltd. 2.0 % Alibaba Group Holding Ltd. 1.8 % Mahindra & Mahindra Ltd. 1.7 % Petrobras 1.7 % Infosys Ltd. 1.4 % Issuer country weightings China 24.7 % India 18.6 % Taiwan 15.8 % South Korea 13.9 % Brazil 5.4 % Indonesia 3.3 % United Arab Emirates 2.9 % Greece 2.2 % Mexico 2.0 % Other Countries 11.2 % | |
| Largest Holdings [Text Block] | Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd. 10.0 % Tencent Holdings Ltd. 4.6 % Samsung Electronics Co. Ltd. 4.4 % Hon Hai Precision Industry Co. Ltd. 2.1 % China Construction Bank Corp. 2.1 % Tata Consultancy Services Ltd. 2.0 % Alibaba Group Holding Ltd. 1.8 % Mahindra & Mahindra Ltd. 1.7 % Petrobras 1.7 % Infosys Ltd. 1.4 % | |
| C000159998 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Blended Research® Emerging Markets Equity Fund | |
| Class Name | Class R2 | |
| Trading Symbol | BRKSX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Blended Research Emerging Markets Equity Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R2 $ 1.49 % | |
| Expenses Paid, Amount | $ 163 | |
| Expense Ratio, Percent | 1.49% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R2 shares of the MFS Blended Research Emerging Markets Equity Fund (fund) provided a total return of 18.44%, at net asset value. This compares with a return of 15.07% for the fund’s benchmark, the MSCI Emerging Markets Index (net div). As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI Emerging Markets Index: Security selection within both the information technology and financials sectors contributed to relative performance. Top detractors from performance relative to the MSCI Emerging Markets Index: Weak stock selection within the communication services sector held back relative results. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment* This graph shows the performance of a hypothetical $10,000 investment in Class R2 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods. Share Class 1-yr 5-yr Life* R2 without sales charge 18.44 % 5.33 % 6.36 % Comparative Benchmark(s) MSCI Emerging Markets Index (net div) ∆ 15.07 % 4.79 % 6.03 % * For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024. ∆ Source: FactSet Research Systems Inc. | |
| Performance Inception Date | Sep. 15, 2015 | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r2 | |
| Net Assets | $ 91,229,346 | |
| Holdings Count | Holding | 137 | |
| Advisory Fees Paid, Amount | $ 471,631 | [34] |
| Investment Company Portfolio Turnover | 58% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 91,229,346 Total Management Fee ($)#: 471,631 Total Number of Holdings: 137 Portfolio Turnover Rate (%): 58 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 98.4 % Money Market Funds 1.6 % Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd. 10.0 % Tencent Holdings Ltd. 4.6 % Samsung Electronics Co. Ltd. 4.4 % Hon Hai Precision Industry Co. Ltd. 2.1 % China Construction Bank Corp. 2.1 % Tata Consultancy Services Ltd. 2.0 % Alibaba Group Holding Ltd. 1.8 % Mahindra & Mahindra Ltd. 1.7 % Petrobras 1.7 % Infosys Ltd. 1.4 % Issuer country weightings China 24.7 % India 18.6 % Taiwan 15.8 % South Korea 13.9 % Brazil 5.4 % Indonesia 3.3 % United Arab Emirates 2.9 % Greece 2.2 % Mexico 2.0 % Other Countries 11.2 % | |
| Largest Holdings [Text Block] | Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd. 10.0 % Tencent Holdings Ltd. 4.6 % Samsung Electronics Co. Ltd. 4.4 % Hon Hai Precision Industry Co. Ltd. 2.1 % China Construction Bank Corp. 2.1 % Tata Consultancy Services Ltd. 2.0 % Alibaba Group Holding Ltd. 1.8 % Mahindra & Mahindra Ltd. 1.7 % Petrobras 1.7 % Infosys Ltd. 1.4 % | |
| C000159999 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Blended Research® Emerging Markets Equity Fund | |
| Class Name | Class R3 | |
| Trading Symbol | BRKTX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Blended Research Emerging Markets Equity Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R3 $ 1.24 % | |
| Expenses Paid, Amount | $ 136 | |
| Expense Ratio, Percent | 1.24% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R3 shares of the MFS Blended Research Emerging Markets Equity Fund (fund) provided a total return of 18.76%, at net asset value. This compares with a return of 15.07% for the fund’s benchmark, the MSCI Emerging Markets Index (net div). As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI Emerging Markets Index: Security selection within both the information technology and financials sectors contributed to relative performance. Top detractors from performance relative to the MSCI Emerging Markets Index: Weak stock selection within the communication services sector held back relative results. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment* This graph shows the performance of a hypothetical $10,000 investment in Class R3 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods. Share Class 1-yr 5-yr Life* R3 without sales charge 18.76 % 5.59 % 6.62 % Comparative Benchmark(s) MSCI Emerging Markets Index (net div) ∆ 15.07 % 4.79 % 6.03 % * For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024. ∆ Source: FactSet Research Systems Inc. | |
| Performance Inception Date | Sep. 15, 2015 | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r3 | |
| Net Assets | $ 91,229,346 | |
| Holdings Count | Holding | 137 | |
| Advisory Fees Paid, Amount | $ 471,631 | [35] |
| Investment Company Portfolio Turnover | 58% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 91,229,346 Total Management Fee ($)#: 471,631 Total Number of Holdings: 137 Portfolio Turnover Rate (%): 58 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 98.4 % Money Market Funds 1.6 % Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd. 10.0 % Tencent Holdings Ltd. 4.6 % Samsung Electronics Co. Ltd. 4.4 % Hon Hai Precision Industry Co. Ltd. 2.1 % China Construction Bank Corp. 2.1 % Tata Consultancy Services Ltd. 2.0 % Alibaba Group Holding Ltd. 1.8 % Mahindra & Mahindra Ltd. 1.7 % Petrobras 1.7 % Infosys Ltd. 1.4 % Issuer country weightings China 24.7 % India 18.6 % Taiwan 15.8 % South Korea 13.9 % Brazil 5.4 % Indonesia 3.3 % United Arab Emirates 2.9 % Greece 2.2 % Mexico 2.0 % Other Countries 11.2 % | |
| Largest Holdings [Text Block] | Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd. 10.0 % Tencent Holdings Ltd. 4.6 % Samsung Electronics Co. Ltd. 4.4 % Hon Hai Precision Industry Co. Ltd. 2.1 % China Construction Bank Corp. 2.1 % Tata Consultancy Services Ltd. 2.0 % Alibaba Group Holding Ltd. 1.8 % Mahindra & Mahindra Ltd. 1.7 % Petrobras 1.7 % Infosys Ltd. 1.4 % | |
| C000160000 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Blended Research® Emerging Markets Equity Fund | |
| Class Name | Class R4 | |
| Trading Symbol | BRKUX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Blended Research Emerging Markets Equity Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R4 $ 0.99 % | |
| Expenses Paid, Amount | $ 108 | |
| Expense Ratio, Percent | 0.99% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R4 shares of the MFS Blended Research Emerging Markets Equity Fund (fund) provided a total return of 19.01%, at net asset value. This compares with a return of 15.07% for the fund’s benchmark, the MSCI Emerging Markets Index (net div). As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI Emerging Markets Index: Security selection within both the information technology and financials sectors contributed to relative performance. Top detractors from performance relative to the MSCI Emerging Markets Index: Weak stock selection within the communication services sector held back relative results. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment* This graph shows the performance of a hypothetical $10,000 investment in Class R4 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods. Share Class 1-yr 5-yr Life* R4 without sales charge 19.01 % 5.85 % 6.89 % Comparative Benchmark(s) MSCI Emerging Markets Index (net div) ∆ 15.07 % 4.79 % 6.03 % * For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024. ∆ Source: FactSet Research Systems Inc. | |
| Performance Inception Date | Sep. 15, 2015 | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r4 | |
| Net Assets | $ 91,229,346 | |
| Holdings Count | Holding | 137 | |
| Advisory Fees Paid, Amount | $ 471,631 | [36] |
| Investment Company Portfolio Turnover | 58% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 91,229,346 Total Management Fee ($)#: 471,631 Total Number of Holdings: 137 Portfolio Turnover Rate (%): 58 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 98.4 % Money Market Funds 1.6 % Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd. 10.0 % Tencent Holdings Ltd. 4.6 % Samsung Electronics Co. Ltd. 4.4 % Hon Hai Precision Industry Co. Ltd. 2.1 % China Construction Bank Corp. 2.1 % Tata Consultancy Services Ltd. 2.0 % Alibaba Group Holding Ltd. 1.8 % Mahindra & Mahindra Ltd. 1.7 % Petrobras 1.7 % Infosys Ltd. 1.4 % Issuer country weightings China 24.7 % India 18.6 % Taiwan 15.8 % South Korea 13.9 % Brazil 5.4 % Indonesia 3.3 % United Arab Emirates 2.9 % Greece 2.2 % Mexico 2.0 % Other Countries 11.2 % | |
| Largest Holdings [Text Block] | Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd. 10.0 % Tencent Holdings Ltd. 4.6 % Samsung Electronics Co. Ltd. 4.4 % Hon Hai Precision Industry Co. Ltd. 2.1 % China Construction Bank Corp. 2.1 % Tata Consultancy Services Ltd. 2.0 % Alibaba Group Holding Ltd. 1.8 % Mahindra & Mahindra Ltd. 1.7 % Petrobras 1.7 % Infosys Ltd. 1.4 % | |
| C000160001 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | MFS® Blended Research® Emerging Markets Equity Fund | |
| Class Name | Class R6 | |
| Trading Symbol | BRKVX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about MFS Blended Research Emerging Markets Equity Fund for the period of September 1, 2023 to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at funds.mfs.com | |
| Additional Information Phone Number | 1‑800‑225‑2606 | |
| Additional Information Email | orderliterature@mfs.com | |
| Additional Information Website | funds.mfs.com | |
| Expenses [Text Block] | FUND EXPENSES What were the fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment R6 $ 0.90 % | |
| Expenses Paid, Amount | $ 99 | |
| Expense Ratio, Percent | 0.90% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE For the twelve months ended August 31, 2024, Class R6 shares of the MFS Blended Research Emerging Markets Equity Fund (fund) provided a total return of 19.11%, at net asset value. This compares with a return of 15.07% for the fund’s benchmark, the MSCI Emerging Markets Index (net div). As inflation moderated around the globe during the reporting period, several major central banks began to ease monetary policy. Geopolitical strains remained high amid ongoing conflicts in Ukraine and in the Middle East, while relations between China and the US remained tense. The US sought to restrict the flow of advanced technologies to China and China looked to use its industrial overcapacity to increase exports to developed markets to bolster its slow-growing domestic economy. Toward the end of the period, labor markets, particularly in the US, loosened modestly, brightening the inflation outlook. Global equity markets reached record levels during the period as they withstood the adversity of the unsettled geopolitical climate and higher interest rate environment amidst optimism over wide-scale adoption of artificial intelligence. Top contributors to performance relative to the MSCI Emerging Markets Index: Security selection within both the information technology and financials sectors contributed to relative performance. Top detractors from performance relative to the MSCI Emerging Markets Index: Weak stock selection within the communication services sector held back relative results. | |
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance is not a good predictor of the fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE The fund’s past performance is not a good predictor of the fund’s future performance. Growth of a Hypothetical $10,000 Investment* This graph shows the performance of a hypothetical $10,000 investment in Class R6 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge, if any. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns through 8/31/24 This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods. Share Class 1-yr 5-yr Life* R6 without sales charge 19.11 % 5.95 % 6.98 % Comparative Benchmark(s) MSCI Emerging Markets Index (net div) ∆ 15.07 % 4.79 % 6.03 % * For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024. ∆ Source: FactSet Research Systems Inc. | |
| Performance Inception Date | Sep. 15, 2015 | |
| No Deduction of Taxes [Text Block] | The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit mfs.com/perf/r6 | |
| Net Assets | $ 91,229,346 | |
| Holdings Count | Holding | 137 | |
| Advisory Fees Paid, Amount | $ 471,631 | [37] |
| Investment Company Portfolio Turnover | 58% | |
| Additional Fund Statistics [Text Block] | FUND STATISTICS AS OF 8/31/24 Net Assets ($): 91,229,346 Total Management Fee ($)#: 471,631 Total Number of Holdings: 137 Portfolio Turnover Rate (%): 58 # Where the fund holds derivatives, they are not included in the total number of portfolio holdings. | |
| Holdings [Text Block] | PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/24) Portfolio structure Equities 98.4 % Money Market Funds 1.6 % Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd. 10.0 % Tencent Holdings Ltd. 4.6 % Samsung Electronics Co. Ltd. 4.4 % Hon Hai Precision Industry Co. Ltd. 2.1 % China Construction Bank Corp. 2.1 % Tata Consultancy Services Ltd. 2.0 % Alibaba Group Holding Ltd. 1.8 % Mahindra & Mahindra Ltd. 1.7 % Petrobras 1.7 % Infosys Ltd. 1.4 % Issuer country weightings China 24.7 % India 18.6 % Taiwan 15.8 % South Korea 13.9 % Brazil 5.4 % Indonesia 3.3 % United Arab Emirates 2.9 % Greece 2.2 % Mexico 2.0 % Other Countries 11.2 % | |
| Largest Holdings [Text Block] | Top ten holdings Taiwan Semiconductor Manufacturing Co. Ltd. 10.0 % Tencent Holdings Ltd. 4.6 % Samsung Electronics Co. Ltd. 4.4 % Hon Hai Precision Industry Co. Ltd. 2.1 % China Construction Bank Corp. 2.1 % Tata Consultancy Services Ltd. 2.0 % Alibaba Group Holding Ltd. 1.8 % Mahindra & Mahindra Ltd. 1.7 % Petrobras 1.7 % Infosys Ltd. 1.4 % | |
| [1]Includes the effect of any management fee waivers.[2]Includes the effect of any management fee waivers.[3]Includes the effect of any management fee waivers.[4]Includes the effect of any management fee waivers.[5]Includes the effect of any management fee waivers.[6]Includes the effect of any management fee waivers.[7]Includes the effect of any management fee waivers.[8]Includes the effect of any management fee waivers.[9]Includes the effect of any management fee waivers.[10]Includes the effect of any management fee waivers.[11]Includes the effect of any management fee waivers.[12]Includes the effect of any management fee waivers.[13]Includes the effect of any management fee waivers.[14]Includes the effect of any management fee waivers.[15]Includes the effect of any management fee waivers.[16]Includes the effect of any management fee waivers.[17]Includes the effect of any management fee waivers.[18]Includes the effect of any management fee waivers.[19]Includes the effect of any management fee waivers.[20]Includes the effect of any management fee waivers.[21]Includes the effect of any management fee waivers.[22]Includes the effect of any management fee waivers.[23]Includes the effect of any management fee waivers.[24]Includes the effect of any management fee waivers.[25]Includes the effect of any management fee waivers.[26]Includes the effect of any management fee waivers.[27]Includes the effect of any management fee waivers.[28]Includes the effect of any management fee waivers.[29]Includes the effect of any management fee waivers.[30]Includes the effect of any management fee waivers.[31]Includes the effect of any management fee waivers.[32]Includes the effect of any management fee waivers.[33]Includes the effect of any management fee waivers.[34]Includes the effect of any management fee waivers.[35]Includes the effect of any management fee waivers.[36]Includes the effect of any management fee waivers.[37]Includes the effect of any management fee waivers. | ||
| Shareholder Report, Line Graph (Details) - USD ($) | 12 Months Ended | 60 Months Ended | 108 Months Ended | 120 Months Ended | |||||||||||||
| Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2023 | Aug. 31, 2022 | Aug. 31, 2021 | Aug. 31, 2020 | Aug. 31, 2019 | Aug. 31, 2018 | Aug. 31, 2017 | Aug. 31, 2016 | Sep. 15, 2015 | Aug. 31, 2015 | Aug. 31, 2014 | |||
| C000107817 [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | A with initial sales charge (5.75%) | ||||||||||||||||
| Average Annual Return, Percent | 6.90% | 5.96% | 6.84% | ||||||||||||||
| C000107817 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | A without sales charge | ||||||||||||||||
| Account Value | $ 19,376 | $ 19,376 | $ 19,376 | $ 19,376 | $ 17,083 | $ 15,139 | $ 21,538 | $ 16,216 | $ 13,670 | $ 13,900 | $ 11,612 | $ 9,937 | $ 9,397 | $ 9,425 | |||
| Average Annual Return, Percent | 13.42% | 7.23% | 7.47% | ||||||||||||||
| C000107818 [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | B with CDSC (declining over six years from 4% to 0%) | ||||||||||||||||
| Average Annual Return, Percent | [1] | 8.52% | 6.10% | 6.67% | |||||||||||||
| C000107818 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | B without sales charge | ||||||||||||||||
| Account Value | $ 19,072 | $ 19,072 | 19,072 | $ 19,072 | 16,950 | 15,130 | 21,687 | 16,450 | 13,974 | 14,310 | 12,043 | 10,382 | 9,895 | 10,000 | |||
| Average Annual Return, Percent | 12.52% | 6.42% | 6.67% | ||||||||||||||
| C000107819 [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | C with CDSC (1% for 12 months) | ||||||||||||||||
| Average Annual Return, Percent | [2] | 11.58% | 6.42% | 6.67% | |||||||||||||
| C000107819 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | C without sales charge | ||||||||||||||||
| Account Value | $ 19,073 | $ 19,073 | 19,073 | $ 19,073 | 16,941 | 15,130 | 21,687 | 16,450 | 13,974 | 14,310 | 12,043 | 10,382 | 9,895 | 10,000 | |||
| Average Annual Return, Percent | 12.58% | 6.42% | 6.67% | ||||||||||||||
| C000107820 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | I without sales charge | ||||||||||||||||
| Account Value | $ 21,080 | $ 21,080 | 21,080 | $ 21,080 | 18,542 | 16,390 | 23,265 | 17,472 | 14,690 | 14,900 | 12,416 | 10,594 | 9,997 | 10,000 | |||
| Average Annual Return, Percent | 13.69% | 7.49% | 7.74% | ||||||||||||||
| C000107821 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R1 without sales charge | ||||||||||||||||
| Account Value | $ 19,067 | $ 19,067 | 19,067 | $ 19,067 | 16,935 | 15,124 | 21,673 | 16,443 | 13,967 | 14,304 | 12,043 | 10,382 | 9,895 | 10,000 | |||
| Average Annual Return, Percent | 12.59% | 6.42% | 6.67% | ||||||||||||||
| C000107822 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R2 without sales charge | ||||||||||||||||
| Account Value | $ 20,042 | $ 20,042 | 20,042 | $ 20,042 | 17,717 | 15,739 | 22,456 | 16,952 | 14,326 | 14,602 | 12,222 | 10,484 | 9,950 | 10,000 | |||
| Average Annual Return, Percent | 13.12% | 6.95% | 7.20% | ||||||||||||||
| C000107823 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R3 without sales charge | ||||||||||||||||
| Account Value | $ 20,555 | $ 20,555 | 20,555 | $ 20,555 | 18,130 | 16,067 | 22,858 | 17,209 | 14,507 | 14,747 | 12,319 | 10,541 | 9,970 | 10,000 | |||
| Average Annual Return, Percent | 13.38% | 7.22% | 7.47% | ||||||||||||||
| C000107824 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R4 without sales charge | ||||||||||||||||
| Account Value | $ 21,068 | $ 21,068 | 21,068 | $ 21,068 | 18,533 | 16,376 | 23,237 | 17,451 | 14,673 | 14,885 | 12,399 | 10,587 | 9,997 | 10,000 | |||
| Average Annual Return, Percent | 13.68% | 7.50% | 7.74% | ||||||||||||||
| C000124429 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R6 without sales charge | ||||||||||||||||
| Account Value | $ 21,287 | $ 21,287 | $ 21,287 | $ 21,287 | 18,703 | 16,516 | 23,422 | 17,576 | 14,768 | 14,957 | 12,454 | 10,616 | 10,010 | 10,000 | |||
| Average Annual Return, Percent | 13.81% | 7.59% | 7.85% | ||||||||||||||
| C000160011 [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | A with initial sales charge (5.75%) | ||||||||||||||||
| Average Annual Return, Percent | 15.06% | 8.46% | 6.30% | [3] | |||||||||||||
| C000160011 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | A without sales charge | ||||||||||||||||
| Account Value | $ 17,291 | $ 17,291 | $ 17,291 | $ 17,291 | 14,164 | 12,468 | 15,065 | 11,604 | 10,860 | 11,513 | 11,346 | 9,365 | $ 9,425 | ||||
| Average Annual Return, Percent | 22.08% | 9.75% | 7.01% | [3] | |||||||||||||
| C000160012 [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | B with CDSC (declining over six years from 4% to 0%) | ||||||||||||||||
| Average Annual Return, Percent | [4] | 17.15% | 8.61% | 6.19% | [5] | ||||||||||||
| C000160012 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | B without sales charge | ||||||||||||||||
| Account Value | $ 17,126 | $ 17,126 | $ 17,126 | 17,126 | 14,136 | 12,531 | 15,279 | 11,859 | 11,182 | 11,948 | 11,861 | 9,873 | 10,000 | ||||
| Average Annual Return, Percent | 21.15% | 8.90% | 6.19% | [5] | |||||||||||||
| C000160013 [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | C with CDSC (1% for 12 months) | ||||||||||||||||
| Average Annual Return, Percent | [6] | 20.20% | 8.91% | 6.19% | [7] | ||||||||||||
| C000160013 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | C without sales charge | ||||||||||||||||
| Account Value | $ 17,133 | $ 17,133 | $ 17,133 | 17,133 | 14,135 | 12,540 | 15,276 | 11,862 | 11,183 | 11,949 | 11,861 | 9,873 | 10,000 | ||||
| Average Annual Return, Percent | 21.20% | 8.91% | 6.19% | [7] | |||||||||||||
| C000160014 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | I without sales charge | ||||||||||||||||
| Account Value | $ 18,732 | $ 18,732 | $ 18,732 | 18,732 | 15,306 | 13,436 | 16,213 | 12,458 | 11,633 | 12,304 | 12,093 | 9,963 | 10,000 | ||||
| Average Annual Return, Percent | 22.39% | 10% | 7.26% | [8] | |||||||||||||
| C000160015 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R1 without sales charge | ||||||||||||||||
| Account Value | $ 17,133 | $ 17,133 | $ 17,133 | 17,133 | 14,130 | 12,540 | 15,283 | 11,863 | 11,178 | 11,947 | 11,861 | 9,873 | 10,000 | ||||
| Average Annual Return, Percent | 21.25% | 8.92% | 6.19% | [9] | |||||||||||||
| C000160016 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R2 without sales charge | ||||||||||||||||
| Account Value | $ 17,915 | $ 17,915 | $ 17,915 | 17,915 | 14,705 | 12,977 | 15,739 | 12,154 | 11,405 | 12,127 | 11,975 | 9,918 | 10,000 | ||||
| Average Annual Return, Percent | 21.83% | 9.45% | 6.72% | [10] | |||||||||||||
| C000160017 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R3 without sales charge | ||||||||||||||||
| Account Value | $ 18,341 | $ 18,341 | $ 18,341 | 18,341 | 15,024 | 13,217 | 15,996 | 12,328 | 11,530 | 12,230 | 12,050 | 9,956 | 10,000 | ||||
| Average Annual Return, Percent | 22.08% | 9.73% | 7% | [11] | |||||||||||||
| C000160018 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R4 without sales charge | ||||||||||||||||
| Account Value | $ 18,747 | $ 18,747 | $ 18,747 | 18,747 | 15,310 | 13,450 | 16,221 | 12,467 | 11,631 | 12,312 | 12,092 | 9,963 | 10,000 | ||||
| Average Annual Return, Percent | 22.45% | 10.02% | 7.26% | [12] | |||||||||||||
| C000160019 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R6 without sales charge | ||||||||||||||||
| Account Value | $ 18,865 | $ 18,865 | $ 18,865 | $ 18,865 | 15,397 | 13,513 | 16,295 | 12,503 | 11,666 | 12,322 | 12,097 | 9,964 | 10,000 | ||||
| Average Annual Return, Percent | 22.52% | 10.09% | 7.34% | [13] | |||||||||||||
| C000006504 [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | A with initial sales charge (5.75%) | ||||||||||||||||
| Average Annual Return, Percent | 11.16% | 7.78% | 10.47% | ||||||||||||||
| C000006504 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | A without sales charge | ||||||||||||||||
| Account Value | $ 27,072 | $ 27,072 | $ 27,072 | $ 27,072 | 22,955 | 20,680 | 28,148 | 21,603 | 17,540 | 15,927 | 12,473 | 10,712 | 10,118 | 9,425 | |||
| Average Annual Return, Percent | 17.94% | 9.07% | 11.13% | ||||||||||||||
| C000006509 [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | B with CDSC (declining over six years from 4% to 0%) | ||||||||||||||||
| Average Annual Return, Percent | [14] | 13.03% | 7.96% | 10.30% | |||||||||||||
| C000006509 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | B without sales charge | ||||||||||||||||
| Account Value | $ 26,642 | $ 26,642 | 26,642 | $ 26,642 | 22,765 | 20,669 | 28,332 | 21,901 | 17,923 | 16,400 | 12,937 | 11,195 | 10,651 | 10,000 | |||
| Average Annual Return, Percent | 17.03% | 8.25% | 10.30% | ||||||||||||||
| C000006510 [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | C with CDSC (1% for 12 months) | ||||||||||||||||
| Average Annual Return, Percent | [15] | 16.05% | 8.25% | 10.30% | |||||||||||||
| C000006510 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | C without sales charge | ||||||||||||||||
| Account Value | $ 26,643 | $ 26,643 | 26,643 | $ 26,643 | 22,763 | 20,666 | 28,331 | 21,905 | 17,921 | 16,394 | 12,932 | 11,199 | 10,650 | 10,000 | |||
| Average Annual Return, Percent | 17.05% | 8.25% | 10.30% | ||||||||||||||
| C000006511 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | I without sales charge | ||||||||||||||||
| Account Value | $ 29,439 | $ 29,439 | 29,439 | $ 29,439 | 24,908 | 22,388 | 30,384 | 23,265 | 18,845 | 17,067 | 13,328 | 11,421 | 10,757 | 10,000 | |||
| Average Annual Return, Percent | 18.19% | 9.33% | 11.40% | ||||||||||||||
| C000006513 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R1 without sales charge | ||||||||||||||||
| Account Value | $ 26,642 | $ 26,642 | 26,642 | $ 26,642 | 22,766 | 20,669 | 28,341 | 21,908 | 17,931 | 16,401 | 12,941 | 11,200 | 10,654 | 10,000 | |||
| Average Annual Return, Percent | 17.03% | 8.24% | 10.30% | ||||||||||||||
| C000006515 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R2 without sales charge | ||||||||||||||||
| Account Value | $ 28,010 | $ 28,010 | 28,010 | $ 28,010 | 23,816 | 21,513 | 29,349 | 22,576 | 18,380 | 16,734 | 13,138 | 11,312 | 10,704 | 10,000 | |||
| Average Annual Return, Percent | 17.61% | 8.79% | 10.85% | ||||||||||||||
| C000006516 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R3 without sales charge | ||||||||||||||||
| Account Value | $ 28,724 | $ 28,724 | 28,724 | $ 28,724 | 24,355 | 21,945 | 29,864 | 22,921 | 18,610 | 16,897 | 13,228 | 11,365 | 10,732 | 10,000 | |||
| Average Annual Return, Percent | 17.94% | 9.07% | 11.13% | ||||||||||||||
| C000006505 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R4 without sales charge | ||||||||||||||||
| Account Value | $ 29,442 | $ 29,442 | 29,442 | $ 29,442 | 24,909 | 22,391 | 30,383 | 23,262 | 18,843 | 17,068 | 13,336 | 11,427 | 10,765 | 10,000 | |||
| Average Annual Return, Percent | 18.20% | 9.34% | 11.40% | ||||||||||||||
| C000124428 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R6 without sales charge | ||||||||||||||||
| Account Value | $ 29,753 | $ 29,753 | $ 29,753 | $ 29,753 | 25,142 | 22,566 | 30,595 | 23,395 | 18,933 | 17,133 | 13,368 | 11,441 | 10,763 | 10,000 | |||
| Average Annual Return, Percent | 18.34% | 9.46% | 11.52% | ||||||||||||||
| C000159993 [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | A with initial sales charge (5.75%) | ||||||||||||||||
| Average Annual Return, Percent | 11.90% | 4.35% | 5.92% | [16] | |||||||||||||
| C000159993 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | A without sales charge | ||||||||||||||||
| Account Value | $ 16,748 | $ 16,748 | $ 16,748 | $ 16,748 | 14,106 | 13,591 | 17,297 | 13,862 | 12,760 | 13,687 | 13,794 | 10,775 | 9,425 | ||||
| Average Annual Return, Percent | 18.72% | 5.59% | 6.63% | [16] | |||||||||||||
| C000159994 [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | B with CDSC (declining over six years from 4% to 0%) | ||||||||||||||||
| Average Annual Return, Percent | [17] | 13.80% | 4.48% | 5.83% | [18] | ||||||||||||
| C000159994 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | B without sales charge | ||||||||||||||||
| Account Value | $ 16,622 | $ 16,622 | $ 16,622 | 16,622 | 14,110 | 13,689 | 17,546 | 14,176 | 13,141 | 14,208 | 14,430 | 11,346 | 10,000 | ||||
| Average Annual Return, Percent | 17.80% | 4.81% | 5.83% | [18] | |||||||||||||
| C000159995 [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | C with CDSC (1% for 12 months) | ||||||||||||||||
| Average Annual Return, Percent | [19] | 16.79% | 4.80% | 5.83% | [20] | ||||||||||||
| C000159995 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | C without sales charge | ||||||||||||||||
| Account Value | $ 16,611 | $ 16,611 | $ 16,611 | 16,611 | 14,102 | 13,680 | 17,543 | 14,173 | 13,140 | 14,206 | 14,420 | 11,348 | 10,000 | ||||
| Average Annual Return, Percent | 17.79% | 4.80% | 5.83% | [20] | |||||||||||||
| C000159996 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | I without sales charge | ||||||||||||||||
| Account Value | $ 18,166 | $ 18,166 | $ 18,166 | 18,166 | 15,265 | 14,670 | 18,619 | 14,883 | 13,668 | 14,626 | 14,708 | 11,451 | 10,000 | ||||
| Average Annual Return, Percent | 19% | 5.85% | 6.89% | [21] | |||||||||||||
| C000159997 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R1 without sales charge | ||||||||||||||||
| Account Value | $ 17,054 | $ 17,054 | $ 17,054 | 17,054 | 14,371 | 13,842 | 17,617 | 14,172 | 13,142 | 14,203 | 14,418 | 11,346 | 10,000 | ||||
| Average Annual Return, Percent | 18.67% | 5.35% | 6.14% | [22] | |||||||||||||
| C000159998 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R2 without sales charge | ||||||||||||||||
| Account Value | $ 17,382 | $ 17,382 | $ 17,382 | 17,382 | 14,676 | 14,165 | 18,084 | 14,528 | 13,409 | 14,413 | 14,563 | 11,404 | 10,000 | ||||
| Average Annual Return, Percent | 18.44% | 5.33% | 6.36% | [23] | |||||||||||||
| C000159999 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R3 without sales charge | ||||||||||||||||
| Account Value | $ 17,764 | $ 17,764 | $ 17,764 | 17,764 | 14,959 | 14,407 | 18,341 | 14,697 | 13,531 | 14,522 | 14,639 | 11,422 | 10,000 | ||||
| Average Annual Return, Percent | 18.76% | 5.59% | 6.62% | [24] | |||||||||||||
| C000160000 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R4 without sales charge | ||||||||||||||||
| Account Value | $ 18,168 | $ 18,168 | $ 18,168 | 18,168 | 15,266 | 14,672 | 18,628 | 14,891 | 13,674 | 14,632 | 14,706 | 11,451 | 10,000 | ||||
| Average Annual Return, Percent | 19.01% | 5.85% | 6.89% | [25] | |||||||||||||
| C000160001 [Member] | Without Sales Load [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | R6 without sales charge | ||||||||||||||||
| Account Value | $ 18,308 | $ 18,308 | $ 18,308 | 18,308 | 15,371 | 14,745 | 18,708 | 14,946 | 13,712 | 14,661 | 14,723 | 11,462 | 10,000 | ||||
| Average Annual Return, Percent | 19.11% | 5.95% | 6.98% | [26] | |||||||||||||
| MSCI All Country World Index net div [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | MSCI All Country World Index (net div) | ||||||||||||||||
| Account Value | $ 23,192 | $ 23,192 | $ 23,192 | $ 23,192 | 18,788 | 16,488 | 19,601 | 15,237 | 13,077 | 13,113 | 11,770 | 10,050 | 9,371 | 10,000 | |||
| Average Annual Return, Percent | [27],[28] | 23.44% | 12.14% | 8.78% | |||||||||||||
| MSCI All Country World ex US Index net div [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | MSCI All Country World (ex-US) Index (net div) | ||||||||||||||||
| Account Value | $ 17,949 | $ 17,949 | $ 17,949 | $ 17,949 | 15,184 | 13,570 | 16,861 | 13,503 | 12,467 | 12,888 | 12,491 | 10,507 | 10,000 | ||||
| Average Annual Return, Percent | [29] | 18.21% | 7.56% | 6.74% | [3] | ||||||||||||
| Russell 3000 Index [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | Russell 3000® Index | ||||||||||||||||
| Account Value | $ 32,071 | $ 32,071 | $ 32,071 | $ 32,071 | 25,424 | 22,155 | 25,548 | 19,203 | 15,813 | 15,608 | 12,980 | 11,184 | 10,036 | 10,000 | |||
| Average Annual Return, Percent | [30],[31] | 26.14% | 15.19% | 12.36% | |||||||||||||
| MSCI Emerging Markets Index net div [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | MSCI Emerging Markets Index (net div) | ||||||||||||||||
| Account Value | $ 16,911 | $ 16,911 | $ 16,911 | $ 16,911 | 14,696 | 14,515 | 18,562 | 15,325 | 13,386 | 13,996 | 14,092 | 11,316 | $ 10,000 | ||||
| Average Annual Return, Percent | [32] | 15.07% | 4.79% | 6.03% | [16] | ||||||||||||
| MSCI All Country World Small Mid Cap Index net div [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | MSCI All Country World Small Mid Cap Index (net div) | ||||||||||||||||
| Account Value | $ 19,438 | $ 19,438 | $ 19,438 | $ 19,438 | 16,629 | 15,328 | 18,848 | 13,637 | 12,562 | 13,368 | 11,899 | 10,234 | 9,523 | 10,000 | |||
| Average Annual Return, Percent | [27],[28] | 16.90% | 9.12% | 6.87% | |||||||||||||
| Russell Midcap Growth Index [Member] | |||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||
| Line Graph and Table Measure Name | Russell Midcap® Growth Index | ||||||||||||||||
| Account Value | $ 27,408 | $ 27,408 | $ 27,408 | $ 27,408 | $ 23,019 | $ 20,371 | $ 27,788 | $ 20,557 | $ 16,638 | $ 15,702 | $ 12,556 | $ 10,963 | $ 10,246 | $ 10,000 | |||
| Average Annual Return, Percent | [30],[31] | 19.07% | 10.50% | 10.61% | |||||||||||||
| [1]Assuming redemption at the end of the applicable period.[2]Assuming redemption at the end of the applicable period.[3]For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024.[4]Assuming redemption at the end of the applicable period.[5]For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024.[6]Assuming redemption at the end of the applicable period.[7]For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024.[8]For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024.[9]For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024.[10]For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024.[11]For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024.[12]For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024.[13]For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024.[14]Assuming redemption at the end of the applicable period.[15]Assuming redemption at the end of the applicable period.[16]For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024.[17]Assuming redemption at the end of the applicable period.[18]For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024.[19]Assuming redemption at the end of the applicable period.[20]For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024.[21]For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024.[22]For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024.[23]For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024.[24]For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024.[25]For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024.[26]For the period from the commencement of the class's investment operations, September 15, 2015 through August 31, 2024.[27]Effective May 1, 2024, the MSCI All Country World Index (net div) replaced the MSCI All Country World Small Mid Cap Index (net div) as a broad measure of market performance in accordance with new regulatory disclosure requirements. The fund continues to use the MSCI All Country World Small Mid Cap Index (net div) as an additional benchmark that MFS believes more closely reflects the market segments in which the fund invests.[28]Source: FactSet Research Systems Inc.[29]Source: FactSet Research Systems Inc.[30]Effective May 1, 2024, the Russell 3000 ® ® ® | |||||||||||||||||
| Shareholder Report, Holdings (Details) | Aug. 31, 2024 |
| C000107817 [Member] | Cranswick PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.60% |
| C000107817 [Member] | GFL Environmental Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000107817 [Member] | Wabtec Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000107817 [Member] | ICON PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000107817 [Member] | Howmet Aerospace Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107817 [Member] | Euronext N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107817 [Member] | AUB Group Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107817 [Member] | STERIS PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.90% |
| C000107817 [Member] | Burlington Stores Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000107817 [Member] | Jacobs Solutions Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000107817 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 12% |
| C000107817 [Member] | AUSTRALIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000107817 [Member] | BRAZIL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000107817 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000107817 [Member] | SWITZERLAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000107817 [Member] | GERMANY | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000107817 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000107817 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.10% |
| C000107817 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.60% |
| C000107817 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 43.80% |
| C000107817 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.20% |
| C000107817 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.80% |
| C000107818 [Member] | Cranswick PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.60% |
| C000107818 [Member] | GFL Environmental Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000107818 [Member] | Wabtec Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000107818 [Member] | ICON PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000107818 [Member] | Howmet Aerospace Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107818 [Member] | Euronext N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107818 [Member] | AUB Group Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107818 [Member] | STERIS PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.90% |
| C000107818 [Member] | Burlington Stores Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000107818 [Member] | Jacobs Solutions Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000107818 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 12% |
| C000107818 [Member] | AUSTRALIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000107818 [Member] | BRAZIL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000107818 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000107818 [Member] | SWITZERLAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000107818 [Member] | GERMANY | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000107818 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000107818 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.10% |
| C000107818 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.60% |
| C000107818 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 43.80% |
| C000107818 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.20% |
| C000107818 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.80% |
| C000107819 [Member] | Cranswick PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.60% |
| C000107819 [Member] | GFL Environmental Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000107819 [Member] | Wabtec Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000107819 [Member] | ICON PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000107819 [Member] | Howmet Aerospace Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107819 [Member] | Euronext N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107819 [Member] | AUB Group Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107819 [Member] | STERIS PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.90% |
| C000107819 [Member] | Burlington Stores Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000107819 [Member] | Jacobs Solutions Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000107819 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 12% |
| C000107819 [Member] | AUSTRALIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000107819 [Member] | BRAZIL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000107819 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000107819 [Member] | SWITZERLAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000107819 [Member] | GERMANY | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000107819 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000107819 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.10% |
| C000107819 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.60% |
| C000107819 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 43.80% |
| C000107819 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.20% |
| C000107819 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.80% |
| C000107820 [Member] | Cranswick PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.60% |
| C000107820 [Member] | GFL Environmental Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000107820 [Member] | Wabtec Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000107820 [Member] | ICON PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000107820 [Member] | Howmet Aerospace Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107820 [Member] | Euronext N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107820 [Member] | AUB Group Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107820 [Member] | STERIS PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.90% |
| C000107820 [Member] | Burlington Stores Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000107820 [Member] | Jacobs Solutions Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000107820 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 12% |
| C000107820 [Member] | AUSTRALIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000107820 [Member] | BRAZIL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000107820 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000107820 [Member] | SWITZERLAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000107820 [Member] | GERMANY | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000107820 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000107820 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.10% |
| C000107820 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.60% |
| C000107820 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 43.80% |
| C000107820 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.20% |
| C000107820 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.80% |
| C000107821 [Member] | Cranswick PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.60% |
| C000107821 [Member] | GFL Environmental Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000107821 [Member] | Wabtec Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000107821 [Member] | ICON PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000107821 [Member] | Howmet Aerospace Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107821 [Member] | Euronext N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107821 [Member] | AUB Group Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107821 [Member] | STERIS PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.90% |
| C000107821 [Member] | Burlington Stores Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000107821 [Member] | Jacobs Solutions Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000107821 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 12% |
| C000107821 [Member] | AUSTRALIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000107821 [Member] | BRAZIL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000107821 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000107821 [Member] | SWITZERLAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000107821 [Member] | GERMANY | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000107821 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000107821 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.10% |
| C000107821 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.60% |
| C000107821 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 43.80% |
| C000107821 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.20% |
| C000107821 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.80% |
| C000107822 [Member] | Cranswick PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.60% |
| C000107822 [Member] | GFL Environmental Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000107822 [Member] | Wabtec Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000107822 [Member] | ICON PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000107822 [Member] | Howmet Aerospace Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107822 [Member] | Euronext N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107822 [Member] | AUB Group Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107822 [Member] | STERIS PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.90% |
| C000107822 [Member] | Burlington Stores Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000107822 [Member] | Jacobs Solutions Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000107822 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 12% |
| C000107822 [Member] | AUSTRALIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000107822 [Member] | BRAZIL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000107822 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000107822 [Member] | SWITZERLAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000107822 [Member] | GERMANY | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000107822 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000107822 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.10% |
| C000107822 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.60% |
| C000107822 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 43.80% |
| C000107822 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.20% |
| C000107822 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.80% |
| C000107823 [Member] | Cranswick PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.60% |
| C000107823 [Member] | GFL Environmental Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000107823 [Member] | Wabtec Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000107823 [Member] | ICON PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000107823 [Member] | Howmet Aerospace Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107823 [Member] | Euronext N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107823 [Member] | AUB Group Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107823 [Member] | STERIS PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.90% |
| C000107823 [Member] | Burlington Stores Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000107823 [Member] | Jacobs Solutions Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000107823 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 12% |
| C000107823 [Member] | AUSTRALIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000107823 [Member] | BRAZIL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000107823 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000107823 [Member] | SWITZERLAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000107823 [Member] | GERMANY | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000107823 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000107823 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.10% |
| C000107823 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.60% |
| C000107823 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 43.80% |
| C000107823 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.20% |
| C000107823 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.80% |
| C000107824 [Member] | Cranswick PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.60% |
| C000107824 [Member] | GFL Environmental Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000107824 [Member] | Wabtec Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000107824 [Member] | ICON PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000107824 [Member] | Howmet Aerospace Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107824 [Member] | Euronext N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107824 [Member] | AUB Group Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000107824 [Member] | STERIS PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.90% |
| C000107824 [Member] | Burlington Stores Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000107824 [Member] | Jacobs Solutions Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000107824 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 12% |
| C000107824 [Member] | AUSTRALIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000107824 [Member] | BRAZIL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000107824 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000107824 [Member] | SWITZERLAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000107824 [Member] | GERMANY | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000107824 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000107824 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.10% |
| C000107824 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.60% |
| C000107824 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 43.80% |
| C000107824 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.20% |
| C000107824 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.80% |
| C000124429 [Member] | Cranswick PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.60% |
| C000124429 [Member] | GFL Environmental Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000124429 [Member] | Wabtec Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000124429 [Member] | ICON PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000124429 [Member] | Howmet Aerospace Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000124429 [Member] | Euronext N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000124429 [Member] | AUB Group Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000124429 [Member] | STERIS PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.90% |
| C000124429 [Member] | Burlington Stores Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000124429 [Member] | Jacobs Solutions Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000124429 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 12% |
| C000124429 [Member] | AUSTRALIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000124429 [Member] | BRAZIL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000124429 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000124429 [Member] | SWITZERLAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000124429 [Member] | GERMANY | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000124429 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000124429 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.10% |
| C000124429 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.60% |
| C000124429 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 43.80% |
| C000124429 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.20% |
| C000124429 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.80% |
| C000006517 [Member] | Zero To 7 days [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 32% |
| C000006517 [Member] | Eight To 29 days [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 27.90% |
| C000006517 [Member] | Thirty To 59 days [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 24% |
| C000006517 [Member] | Sixty To 89 days [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 12.40% |
| C000006517 [Member] | Ninety To 365 days [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.70% |
| C000006517 [Member] | A 1Plus [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 62.90% |
| C000006517 [Member] | A 1 [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 37.10% |
| C000006517 [Member] | U S Treasury and U S Government Agency Securities and Equivalents [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 73.80% |
| C000006517 [Member] | Repurchase Agreements collateralized by U S Treasury and or U S Government Agency Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 26.20% |
| C000160011 [Member] | Taiwan Semiconductor Manufacturing Co Ltd ADR [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000160011 [Member] | Roche Holding AG [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000160011 [Member] | ASML Holding N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160011 [Member] | KDDI Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160011 [Member] | UBS Group AG [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160011 [Member] | Tata Consultancy Services Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160011 [Member] | Tencent Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160011 [Member] | Samsung Electronics Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160011 [Member] | Sanofi [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160011 [Member] | DBS Group Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160011 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 30.20% |
| C000160011 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.70% |
| C000160011 [Member] | SWITZERLAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000160011 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.30% |
| C000160011 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.40% |
| C000160011 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 14.80% |
| C000160011 [Member] | CHINA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 7% |
| C000160011 [Member] | KOREA, REPUBLIC OF | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.80% |
| C000160011 [Member] | NETHERLANDS | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.30% |
| C000160011 [Member] | TAIWAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.90% |
| C000160011 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 99.20% |
| C000160011 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.80% |
| C000160012 [Member] | Taiwan Semiconductor Manufacturing Co Ltd ADR [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000160012 [Member] | Roche Holding AG [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000160012 [Member] | ASML Holding N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160012 [Member] | KDDI Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160012 [Member] | UBS Group AG [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160012 [Member] | Tata Consultancy Services Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160012 [Member] | Tencent Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160012 [Member] | Samsung Electronics Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160012 [Member] | Sanofi [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160012 [Member] | DBS Group Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160012 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 30.20% |
| C000160012 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.70% |
| C000160012 [Member] | SWITZERLAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000160012 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.30% |
| C000160012 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.40% |
| C000160012 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 14.80% |
| C000160012 [Member] | CHINA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 7% |
| C000160012 [Member] | KOREA, REPUBLIC OF | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.80% |
| C000160012 [Member] | NETHERLANDS | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.30% |
| C000160012 [Member] | TAIWAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.90% |
| C000160012 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 99.20% |
| C000160012 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.80% |
| C000160013 [Member] | Taiwan Semiconductor Manufacturing Co Ltd ADR [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000160013 [Member] | Roche Holding AG [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000160013 [Member] | ASML Holding N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160013 [Member] | KDDI Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160013 [Member] | UBS Group AG [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160013 [Member] | Tata Consultancy Services Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160013 [Member] | Tencent Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160013 [Member] | Samsung Electronics Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160013 [Member] | Sanofi [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160013 [Member] | DBS Group Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160013 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 30.20% |
| C000160013 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.70% |
| C000160013 [Member] | SWITZERLAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000160013 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.30% |
| C000160013 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.40% |
| C000160013 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 14.80% |
| C000160013 [Member] | CHINA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 7% |
| C000160013 [Member] | KOREA, REPUBLIC OF | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.80% |
| C000160013 [Member] | NETHERLANDS | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.30% |
| C000160013 [Member] | TAIWAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.90% |
| C000160013 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 99.20% |
| C000160013 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.80% |
| C000160014 [Member] | Taiwan Semiconductor Manufacturing Co Ltd ADR [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000160014 [Member] | Roche Holding AG [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000160014 [Member] | ASML Holding N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160014 [Member] | KDDI Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160014 [Member] | UBS Group AG [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160014 [Member] | Tata Consultancy Services Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160014 [Member] | Tencent Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160014 [Member] | Samsung Electronics Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160014 [Member] | Sanofi [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160014 [Member] | DBS Group Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160014 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 30.20% |
| C000160014 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.70% |
| C000160014 [Member] | SWITZERLAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000160014 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.30% |
| C000160014 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.40% |
| C000160014 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 14.80% |
| C000160014 [Member] | CHINA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 7% |
| C000160014 [Member] | KOREA, REPUBLIC OF | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.80% |
| C000160014 [Member] | NETHERLANDS | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.30% |
| C000160014 [Member] | TAIWAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.90% |
| C000160014 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 99.20% |
| C000160014 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.80% |
| C000160015 [Member] | Taiwan Semiconductor Manufacturing Co Ltd ADR [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000160015 [Member] | Roche Holding AG [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000160015 [Member] | ASML Holding N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160015 [Member] | KDDI Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160015 [Member] | UBS Group AG [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160015 [Member] | Tata Consultancy Services Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160015 [Member] | Tencent Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160015 [Member] | Samsung Electronics Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160015 [Member] | Sanofi [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160015 [Member] | DBS Group Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160015 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 30.20% |
| C000160015 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.70% |
| C000160015 [Member] | SWITZERLAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000160015 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.30% |
| C000160015 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.40% |
| C000160015 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 14.80% |
| C000160015 [Member] | CHINA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 7% |
| C000160015 [Member] | KOREA, REPUBLIC OF | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.80% |
| C000160015 [Member] | NETHERLANDS | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.30% |
| C000160015 [Member] | TAIWAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.90% |
| C000160015 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 99.20% |
| C000160015 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.80% |
| C000160016 [Member] | Taiwan Semiconductor Manufacturing Co Ltd ADR [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000160016 [Member] | Roche Holding AG [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000160016 [Member] | ASML Holding N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160016 [Member] | KDDI Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160016 [Member] | UBS Group AG [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160016 [Member] | Tata Consultancy Services Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160016 [Member] | Tencent Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160016 [Member] | Samsung Electronics Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160016 [Member] | Sanofi [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160016 [Member] | DBS Group Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160016 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 30.20% |
| C000160016 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.70% |
| C000160016 [Member] | SWITZERLAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000160016 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.30% |
| C000160016 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.40% |
| C000160016 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 14.80% |
| C000160016 [Member] | CHINA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 7% |
| C000160016 [Member] | KOREA, REPUBLIC OF | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.80% |
| C000160016 [Member] | NETHERLANDS | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.30% |
| C000160016 [Member] | TAIWAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.90% |
| C000160016 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 99.20% |
| C000160016 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.80% |
| C000160017 [Member] | Taiwan Semiconductor Manufacturing Co Ltd ADR [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000160017 [Member] | Roche Holding AG [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000160017 [Member] | ASML Holding N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160017 [Member] | KDDI Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160017 [Member] | UBS Group AG [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160017 [Member] | Tata Consultancy Services Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160017 [Member] | Tencent Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160017 [Member] | Samsung Electronics Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160017 [Member] | Sanofi [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160017 [Member] | DBS Group Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160017 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 30.20% |
| C000160017 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.70% |
| C000160017 [Member] | SWITZERLAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000160017 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.30% |
| C000160017 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.40% |
| C000160017 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 14.80% |
| C000160017 [Member] | CHINA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 7% |
| C000160017 [Member] | KOREA, REPUBLIC OF | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.80% |
| C000160017 [Member] | NETHERLANDS | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.30% |
| C000160017 [Member] | TAIWAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.90% |
| C000160017 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 99.20% |
| C000160017 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.80% |
| C000160018 [Member] | Roche Holding AG [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000160018 [Member] | ASML Holding N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160018 [Member] | KDDI Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160018 [Member] | UBS Group AG [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160018 [Member] | Tata Consultancy Services Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160018 [Member] | Tencent Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160018 [Member] | Samsung Electronics Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160018 [Member] | Sanofi [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160018 [Member] | DBS Group Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160018 [Member] | Taiwan Semiconductor Manufacturing Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000160018 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 30.20% |
| C000160018 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.70% |
| C000160018 [Member] | SWITZERLAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000160018 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.30% |
| C000160018 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.40% |
| C000160018 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 14.80% |
| C000160018 [Member] | CHINA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 7% |
| C000160018 [Member] | KOREA, REPUBLIC OF | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.80% |
| C000160018 [Member] | NETHERLANDS | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.30% |
| C000160018 [Member] | TAIWAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.90% |
| C000160018 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 99.20% |
| C000160018 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.80% |
| C000160019 [Member] | Roche Holding AG [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000160019 [Member] | ASML Holding N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160019 [Member] | KDDI Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160019 [Member] | UBS Group AG [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160019 [Member] | Tata Consultancy Services Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160019 [Member] | Tencent Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160019 [Member] | Samsung Electronics Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160019 [Member] | Sanofi [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160019 [Member] | DBS Group Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000160019 [Member] | Taiwan Semiconductor Manufacturing Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000160019 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 30.20% |
| C000160019 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 8.70% |
| C000160019 [Member] | SWITZERLAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000160019 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.30% |
| C000160019 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.40% |
| C000160019 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 14.80% |
| C000160019 [Member] | CHINA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 7% |
| C000160019 [Member] | KOREA, REPUBLIC OF | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.80% |
| C000160019 [Member] | NETHERLANDS | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.30% |
| C000160019 [Member] | TAIWAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.90% |
| C000160019 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 99.20% |
| C000160019 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.80% |
| C000006504 [Member] | Howmet Aerospace Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.40% |
| C000006504 [Member] | Monolithic Power Systems Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.50% |
| C000006504 [Member] | Take Two Interactive Software Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006504 [Member] | Bright Horizons Family Solutions Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006504 [Member] | Verisk Analytics Inc A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006504 [Member] | MSCI Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006504 [Member] | Tyler Technologies Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006504 [Member] | Gartner Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006504 [Member] | Spotify Technology S A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006504 [Member] | Wolters Kluwer N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006504 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.90% |
| C000006504 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.40% |
| C000006504 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.90% |
| C000006504 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 23.40% |
| C000006504 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 21.80% |
| C000006504 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006504 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000006504 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.10% |
| C000006504 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.90% |
| C000006504 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 14.60% |
| C000006504 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000006504 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.10% |
| C000006504 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000006509 [Member] | Howmet Aerospace Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.40% |
| C000006509 [Member] | Monolithic Power Systems Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.50% |
| C000006509 [Member] | Take Two Interactive Software Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006509 [Member] | Bright Horizons Family Solutions Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006509 [Member] | Verisk Analytics Inc A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006509 [Member] | MSCI Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006509 [Member] | Tyler Technologies Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006509 [Member] | Gartner Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006509 [Member] | Spotify Technology S A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006509 [Member] | Wolters Kluwer N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006509 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.90% |
| C000006509 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.40% |
| C000006509 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.90% |
| C000006509 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 23.40% |
| C000006509 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 21.80% |
| C000006509 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006509 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000006509 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.10% |
| C000006509 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.90% |
| C000006509 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 14.60% |
| C000006509 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000006509 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.10% |
| C000006509 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000006510 [Member] | Howmet Aerospace Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.40% |
| C000006510 [Member] | Monolithic Power Systems Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.50% |
| C000006510 [Member] | Take Two Interactive Software Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006510 [Member] | Bright Horizons Family Solutions Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006510 [Member] | Verisk Analytics Inc A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006510 [Member] | MSCI Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006510 [Member] | Tyler Technologies Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006510 [Member] | Gartner Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006510 [Member] | Spotify Technology S A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006510 [Member] | Wolters Kluwer N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006510 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.90% |
| C000006510 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.40% |
| C000006510 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.90% |
| C000006510 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 23.40% |
| C000006510 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 21.80% |
| C000006510 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006510 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000006510 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.10% |
| C000006510 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.90% |
| C000006510 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 14.60% |
| C000006510 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000006510 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.10% |
| C000006510 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000006511 [Member] | Howmet Aerospace Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.40% |
| C000006511 [Member] | Monolithic Power Systems Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.50% |
| C000006511 [Member] | Take Two Interactive Software Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006511 [Member] | Bright Horizons Family Solutions Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006511 [Member] | Verisk Analytics Inc A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006511 [Member] | MSCI Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006511 [Member] | Tyler Technologies Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006511 [Member] | Gartner Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006511 [Member] | Spotify Technology S A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006511 [Member] | Wolters Kluwer N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006511 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.90% |
| C000006511 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.40% |
| C000006511 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.90% |
| C000006511 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 23.40% |
| C000006511 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 21.80% |
| C000006511 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006511 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000006511 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.10% |
| C000006511 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.90% |
| C000006511 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 14.60% |
| C000006511 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000006511 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.10% |
| C000006511 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000006513 [Member] | Howmet Aerospace Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.40% |
| C000006513 [Member] | Monolithic Power Systems Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.50% |
| C000006513 [Member] | Take Two Interactive Software Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006513 [Member] | Bright Horizons Family Solutions Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006513 [Member] | Verisk Analytics Inc A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006513 [Member] | MSCI Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006513 [Member] | Tyler Technologies Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006513 [Member] | Gartner Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006513 [Member] | Spotify Technology S A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006513 [Member] | Wolters Kluwer N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006513 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.90% |
| C000006513 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.40% |
| C000006513 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.90% |
| C000006513 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 23.40% |
| C000006513 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 21.80% |
| C000006513 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006513 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000006513 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.10% |
| C000006513 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.90% |
| C000006513 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 14.60% |
| C000006513 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000006513 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.10% |
| C000006513 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000006515 [Member] | Howmet Aerospace Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.40% |
| C000006515 [Member] | Monolithic Power Systems Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.50% |
| C000006515 [Member] | Take Two Interactive Software Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006515 [Member] | Bright Horizons Family Solutions Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006515 [Member] | Verisk Analytics Inc A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006515 [Member] | MSCI Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006515 [Member] | Tyler Technologies Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006515 [Member] | Gartner Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006515 [Member] | Spotify Technology S A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006515 [Member] | Wolters Kluwer N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006515 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.90% |
| C000006515 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.40% |
| C000006515 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.90% |
| C000006515 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 23.40% |
| C000006515 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 21.80% |
| C000006515 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006515 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000006515 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.10% |
| C000006515 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.90% |
| C000006515 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 14.60% |
| C000006515 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000006515 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.10% |
| C000006515 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000006516 [Member] | Howmet Aerospace Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.40% |
| C000006516 [Member] | Monolithic Power Systems Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.50% |
| C000006516 [Member] | Take Two Interactive Software Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006516 [Member] | Bright Horizons Family Solutions Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006516 [Member] | Verisk Analytics Inc A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006516 [Member] | MSCI Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006516 [Member] | Tyler Technologies Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006516 [Member] | Gartner Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006516 [Member] | Spotify Technology S A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006516 [Member] | Wolters Kluwer N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006516 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.90% |
| C000006516 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.40% |
| C000006516 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.90% |
| C000006516 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 23.40% |
| C000006516 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 21.80% |
| C000006516 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006516 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000006516 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.10% |
| C000006516 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.90% |
| C000006516 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 14.60% |
| C000006516 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000006516 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.10% |
| C000006516 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000006505 [Member] | Howmet Aerospace Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.40% |
| C000006505 [Member] | Monolithic Power Systems Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.50% |
| C000006505 [Member] | Take Two Interactive Software Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006505 [Member] | Bright Horizons Family Solutions Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006505 [Member] | Verisk Analytics Inc A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006505 [Member] | MSCI Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006505 [Member] | Tyler Technologies Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006505 [Member] | Gartner Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000006505 [Member] | Spotify Technology S A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006505 [Member] | Wolters Kluwer N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006505 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.90% |
| C000006505 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.40% |
| C000006505 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.90% |
| C000006505 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 23.40% |
| C000006505 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 21.80% |
| C000006505 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000006505 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000006505 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.10% |
| C000006505 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.90% |
| C000006505 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 14.60% |
| C000006505 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000006505 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.10% |
| C000006505 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000124428 [Member] | Howmet Aerospace Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.40% |
| C000124428 [Member] | Monolithic Power Systems Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.50% |
| C000124428 [Member] | Take Two Interactive Software Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000124428 [Member] | Bright Horizons Family Solutions Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000124428 [Member] | Verisk Analytics Inc A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000124428 [Member] | MSCI Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000124428 [Member] | Tyler Technologies Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000124428 [Member] | Gartner Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000124428 [Member] | Spotify Technology S A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000124428 [Member] | Wolters Kluwer N V [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000124428 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.90% |
| C000124428 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.40% |
| C000124428 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.90% |
| C000124428 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 23.40% |
| C000124428 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 21.80% |
| C000124428 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000124428 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000124428 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.10% |
| C000124428 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10.90% |
| C000124428 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 14.60% |
| C000124428 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000124428 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.10% |
| C000124428 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000159993 [Member] | Tata Consultancy Services Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000159993 [Member] | Tencent Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000159993 [Member] | Samsung Electronics Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.40% |
| C000159993 [Member] | Taiwan Semiconductor Manufacturing Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10% |
| C000159993 [Member] | Hon Hai Precision Industry Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000159993 [Member] | China Construction Bank Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000159993 [Member] | Alibaba Group Holding Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000159993 [Member] | Mahindra And Mahindra Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000159993 [Member] | Petrobras [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000159993 [Member] | Infosys Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.40% |
| C000159993 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.20% |
| C000159993 [Member] | BRAZIL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000159993 [Member] | CHINA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 24.70% |
| C000159993 [Member] | KOREA, REPUBLIC OF | |
| Holdings [Line Items] | |
| Percent of Total Investments | 13.90% |
| C000159993 [Member] | TAIWAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 15.80% |
| C000159993 [Member] | MEXICO | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000159993 [Member] | INDONESIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000159993 [Member] | INDIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 18.60% |
| C000159993 [Member] | GREECE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000159993 [Member] | UNITED ARAB EMIRATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000159993 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 98.40% |
| C000159993 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000159994 [Member] | Tata Consultancy Services Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000159994 [Member] | Tencent Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000159994 [Member] | Samsung Electronics Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.40% |
| C000159994 [Member] | Taiwan Semiconductor Manufacturing Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10% |
| C000159994 [Member] | Hon Hai Precision Industry Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000159994 [Member] | China Construction Bank Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000159994 [Member] | Alibaba Group Holding Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000159994 [Member] | Mahindra And Mahindra Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000159994 [Member] | Petrobras [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000159994 [Member] | Infosys Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.40% |
| C000159994 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.20% |
| C000159994 [Member] | BRAZIL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000159994 [Member] | CHINA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 24.70% |
| C000159994 [Member] | KOREA, REPUBLIC OF | |
| Holdings [Line Items] | |
| Percent of Total Investments | 13.90% |
| C000159994 [Member] | TAIWAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 15.80% |
| C000159994 [Member] | MEXICO | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000159994 [Member] | INDONESIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000159994 [Member] | INDIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 18.60% |
| C000159994 [Member] | GREECE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000159994 [Member] | UNITED ARAB EMIRATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000159994 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 98.40% |
| C000159994 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000159995 [Member] | Tata Consultancy Services Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000159995 [Member] | Tencent Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000159995 [Member] | Samsung Electronics Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.40% |
| C000159995 [Member] | Taiwan Semiconductor Manufacturing Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10% |
| C000159995 [Member] | Hon Hai Precision Industry Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000159995 [Member] | China Construction Bank Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000159995 [Member] | Alibaba Group Holding Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000159995 [Member] | Mahindra And Mahindra Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000159995 [Member] | Petrobras [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000159995 [Member] | Infosys Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.40% |
| C000159995 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.20% |
| C000159995 [Member] | BRAZIL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000159995 [Member] | CHINA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 24.70% |
| C000159995 [Member] | KOREA, REPUBLIC OF | |
| Holdings [Line Items] | |
| Percent of Total Investments | 13.90% |
| C000159995 [Member] | TAIWAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 15.80% |
| C000159995 [Member] | MEXICO | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000159995 [Member] | INDONESIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000159995 [Member] | INDIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 18.60% |
| C000159995 [Member] | GREECE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000159995 [Member] | UNITED ARAB EMIRATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000159995 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 98.40% |
| C000159995 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000159996 [Member] | Tata Consultancy Services Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000159996 [Member] | Tencent Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000159996 [Member] | Samsung Electronics Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.40% |
| C000159996 [Member] | Taiwan Semiconductor Manufacturing Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10% |
| C000159996 [Member] | Hon Hai Precision Industry Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000159996 [Member] | China Construction Bank Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000159996 [Member] | Alibaba Group Holding Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000159996 [Member] | Mahindra And Mahindra Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000159996 [Member] | Petrobras [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000159996 [Member] | Infosys Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.40% |
| C000159996 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.20% |
| C000159996 [Member] | BRAZIL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000159996 [Member] | CHINA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 24.70% |
| C000159996 [Member] | KOREA, REPUBLIC OF | |
| Holdings [Line Items] | |
| Percent of Total Investments | 13.90% |
| C000159996 [Member] | TAIWAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 15.80% |
| C000159996 [Member] | MEXICO | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000159996 [Member] | INDONESIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000159996 [Member] | INDIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 18.60% |
| C000159996 [Member] | GREECE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000159996 [Member] | UNITED ARAB EMIRATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000159996 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 98.40% |
| C000159996 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000159997 [Member] | Tata Consultancy Services Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000159997 [Member] | Tencent Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000159997 [Member] | Samsung Electronics Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.40% |
| C000159997 [Member] | Taiwan Semiconductor Manufacturing Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10% |
| C000159997 [Member] | Hon Hai Precision Industry Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000159997 [Member] | China Construction Bank Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000159997 [Member] | Alibaba Group Holding Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000159997 [Member] | Mahindra And Mahindra Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000159997 [Member] | Petrobras [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000159997 [Member] | Infosys Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.40% |
| C000159997 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.20% |
| C000159997 [Member] | BRAZIL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000159997 [Member] | CHINA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 24.70% |
| C000159997 [Member] | KOREA, REPUBLIC OF | |
| Holdings [Line Items] | |
| Percent of Total Investments | 13.90% |
| C000159997 [Member] | TAIWAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 15.80% |
| C000159997 [Member] | MEXICO | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000159997 [Member] | INDONESIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000159997 [Member] | INDIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 18.60% |
| C000159997 [Member] | GREECE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000159997 [Member] | UNITED ARAB EMIRATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000159997 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 98.40% |
| C000159997 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000159998 [Member] | Tata Consultancy Services Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000159998 [Member] | Tencent Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000159998 [Member] | Samsung Electronics Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.40% |
| C000159998 [Member] | Taiwan Semiconductor Manufacturing Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10% |
| C000159998 [Member] | Hon Hai Precision Industry Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000159998 [Member] | China Construction Bank Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000159998 [Member] | Alibaba Group Holding Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000159998 [Member] | Mahindra And Mahindra Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000159998 [Member] | Petrobras [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000159998 [Member] | Infosys Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.40% |
| C000159998 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.20% |
| C000159998 [Member] | BRAZIL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000159998 [Member] | CHINA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 24.70% |
| C000159998 [Member] | KOREA, REPUBLIC OF | |
| Holdings [Line Items] | |
| Percent of Total Investments | 13.90% |
| C000159998 [Member] | TAIWAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 15.80% |
| C000159998 [Member] | MEXICO | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000159998 [Member] | INDONESIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000159998 [Member] | INDIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 18.60% |
| C000159998 [Member] | GREECE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000159998 [Member] | UNITED ARAB EMIRATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000159998 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 98.40% |
| C000159998 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000159999 [Member] | Tata Consultancy Services Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000159999 [Member] | Tencent Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000159999 [Member] | Samsung Electronics Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.40% |
| C000159999 [Member] | Taiwan Semiconductor Manufacturing Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10% |
| C000159999 [Member] | Hon Hai Precision Industry Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000159999 [Member] | China Construction Bank Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000159999 [Member] | Alibaba Group Holding Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000159999 [Member] | Mahindra And Mahindra Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000159999 [Member] | Petrobras [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000159999 [Member] | Infosys Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.40% |
| C000159999 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.20% |
| C000159999 [Member] | BRAZIL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000159999 [Member] | CHINA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 24.70% |
| C000159999 [Member] | KOREA, REPUBLIC OF | |
| Holdings [Line Items] | |
| Percent of Total Investments | 13.90% |
| C000159999 [Member] | TAIWAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 15.80% |
| C000159999 [Member] | MEXICO | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000159999 [Member] | INDONESIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000159999 [Member] | INDIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 18.60% |
| C000159999 [Member] | GREECE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000159999 [Member] | UNITED ARAB EMIRATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000159999 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 98.40% |
| C000159999 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160000 [Member] | Tata Consultancy Services Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000160000 [Member] | Tencent Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000160000 [Member] | Samsung Electronics Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.40% |
| C000160000 [Member] | Taiwan Semiconductor Manufacturing Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10% |
| C000160000 [Member] | Hon Hai Precision Industry Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000160000 [Member] | China Construction Bank Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000160000 [Member] | Alibaba Group Holding Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000160000 [Member] | Mahindra And Mahindra Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160000 [Member] | Petrobras [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160000 [Member] | Infosys Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.40% |
| C000160000 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.20% |
| C000160000 [Member] | BRAZIL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000160000 [Member] | CHINA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 24.70% |
| C000160000 [Member] | KOREA, REPUBLIC OF | |
| Holdings [Line Items] | |
| Percent of Total Investments | 13.90% |
| C000160000 [Member] | TAIWAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 15.80% |
| C000160000 [Member] | MEXICO | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000160000 [Member] | INDONESIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000160000 [Member] | INDIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 18.60% |
| C000160000 [Member] | GREECE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000160000 [Member] | UNITED ARAB EMIRATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000160000 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 98.40% |
| C000160000 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000160001 [Member] | Tata Consultancy Services Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000160001 [Member] | Tencent Holdings Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.60% |
| C000160001 [Member] | Samsung Electronics Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.40% |
| C000160001 [Member] | Taiwan Semiconductor Manufacturing Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 10% |
| C000160001 [Member] | Hon Hai Precision Industry Co Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000160001 [Member] | China Construction Bank Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000160001 [Member] | Alibaba Group Holding Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000160001 [Member] | Mahindra And Mahindra Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160001 [Member] | Petrobras [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.70% |
| C000160001 [Member] | Infosys Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.40% |
| C000160001 [Member] | Other Countries [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 11.20% |
| C000160001 [Member] | BRAZIL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.40% |
| C000160001 [Member] | CHINA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 24.70% |
| C000160001 [Member] | KOREA, REPUBLIC OF | |
| Holdings [Line Items] | |
| Percent of Total Investments | 13.90% |
| C000160001 [Member] | TAIWAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 15.80% |
| C000160001 [Member] | MEXICO | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2% |
| C000160001 [Member] | INDONESIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000160001 [Member] | INDIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 18.60% |
| C000160001 [Member] | GREECE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000160001 [Member] | UNITED ARAB EMIRATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.90% |
| C000160001 [Member] | Equity [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 98.40% |
| C000160001 [Member] | Money Market Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
