| Form N-CSR Cover | 12 Months Ended |
| Oct. 31, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | AMG Funds IV |
| Entity Central Index Key | 0000912036 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Oct. 31, 2024 |
| Shareholder Report | 12 Months Ended |
| Oct. 31, 2024 USD ($) Holding | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | AMG Funds IV |
| Entity Central Index Key | 0000912036 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Oct. 31, 2024 |
| C000003009 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG Montrusco Bolton Large Cap Growth Fund |
| Class Name | Class N |
| Trading Symbol | MCGFX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG Montrusco Bolton Large Cap Growth Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG Montrusco Bolton Large Cap Growth Fund $ 0.91 % |
| Expenses Paid, Amount | $ 104 |
| Expense Ratio, Percent | 0.91% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Market Overview • Performance review • ® Top Contributors and Detractors • • • • ® Positioning • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted over a ten year period, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-, five-, and ten-year periods ended as of October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years 10 Years Class N 29.13 % 13.89 % 11.90 % S&P 500 ® 38.02 % 15.27 % 13.00 % S&P 500 ® 43.67 % 17.01 % 14.76 % |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 208,325,570 |
| Holdings Count | Holding | 27 |
| Advisory Fees Paid, Amount | $ 899,126 |
| Investment Company Portfolio Turnover | 83% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 27 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 83 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund. Top Ten Holdings Apple, Inc. 9.6 % NVIDIA Corp. 9.3 % Microsoft Corp. 9.2 % Adobe, Inc. 8.9 % Alphabet, Inc., Class A 8.3 % Amazon.com, Inc. 4.8 % Texas Instruments, Inc. 4.8 % Meta Platforms, Inc., Class A 4.4 % Workday, Inc., Class A 4.4 % Mastercard, Inc., Class A 3.6 % Top Ten as a Group 67.3 % Portfolio Breakdown |
| Largest Holdings [Text Block] | Top Ten Holdings Apple, Inc. 9.6 % NVIDIA Corp. 9.3 % Microsoft Corp. 9.2 % Adobe, Inc. 8.9 % Alphabet, Inc., Class A 8.3 % Amazon.com, Inc. 4.8 % Texas Instruments, Inc. 4.8 % Meta Platforms, Inc., Class A 4.4 % Workday, Inc., Class A 4.4 % Mastercard, Inc., Class A 3.6 % Top Ten as a Group 67.3 % |
| C000003010 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG Montrusco Bolton Large Cap Growth Fund |
| Class Name | Class I |
| Trading Symbol | MCGIX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG Montrusco Bolton Large Cap Growth Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG Montrusco Bolton Large Cap Growth Fund $ 0.73 % |
| Expenses Paid, Amount | $ 84 |
| Expense Ratio, Percent | 0.73% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Market Overview • Performance review • ® Top Contributors and Detractors • • • • ® Positioning • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted over a ten year period, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-, five-, and ten-year periods ended as of October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years 10 Years Class I 29.43 % 14.10 % 12.12 % S&P 500 ® 38.02 % 15.27 % 13.00 % S&P 500 ® 43.67 % 17.01 % 14.76 % |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 208,325,570 |
| Holdings Count | Holding | 27 |
| Advisory Fees Paid, Amount | $ 899,126 |
| Investment Company Portfolio Turnover | 83% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 27 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 83 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund. Top Ten Holdings Apple, Inc. 9.6 % NVIDIA Corp. 9.3 % Microsoft Corp. 9.2 % Adobe, Inc. 8.9 % Alphabet, Inc., Class A 8.3 % Amazon.com, Inc. 4.8 % Texas Instruments, Inc. 4.8 % Meta Platforms, Inc., Class A 4.4 % Workday, Inc., Class A 4.4 % Mastercard, Inc., Class A 3.6 % Top Ten as a Group 67.3 % Portfolio Breakdown |
| Largest Holdings [Text Block] | Top Ten Holdings Apple, Inc. 9.6 % NVIDIA Corp. 9.3 % Microsoft Corp. 9.2 % Adobe, Inc. 8.9 % Alphabet, Inc., Class A 8.3 % Amazon.com, Inc. 4.8 % Texas Instruments, Inc. 4.8 % Meta Platforms, Inc., Class A 4.4 % Workday, Inc., Class A 4.4 % Mastercard, Inc., Class A 3.6 % Top Ten as a Group 67.3 % |
| C000003029 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG River Road Mid Cap Value Fund |
| Class Name | Class N |
| Trading Symbol | CHTTX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG River Road Mid Cap Value Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG River Road Mid Cap Value Fund $ 1.11 % |
| Expenses Paid, Amount | $ 127 |
| Expense Ratio, Percent | 1.11% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • ® Top Contributors and Detractors • • • • • Positioning • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted over a ten year period, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-, five-, and ten-year periods ended as of October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years 10 Years Class N 28.92 % 12.45 % 7.41 % S&P 500 ® 38.02 % 15.27 % 13.00 % Russell Midcap ® 34.03 % 9.93 % 8.43 % |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 337,940,393 |
| Holdings Count | Holding | 46 |
| Advisory Fees Paid, Amount | $ 1,803,356 |
| Investment Company Portfolio Turnover | 77% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 46 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 77 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund and country allocation is shown as a percentage of total long-term investments of the Fund. Top Ten Holdings iShares Russell Mid-Cap Value ETF 5.4 % Fairfax Financial Holdings, Ltd. (Canada) 4.6 % Willis Towers Watson PLC (United Kingdom) 4.5 % Talen Energy Corp. 4.2 % Lululemon Athletica, Inc. (Canada) 3.9 % Lithia Motors, Inc. 3.9 % Labcorp Holdings, Inc. 3.5 % BJ's Wholesale Club Holdings, Inc. 3.5 % The Kroger Co. 3.2 % Expedia Group, Inc. 2.6 % Top Ten as a Group 39.3 % Portfolio Breakdown |
| Largest Holdings [Text Block] | Top Ten Holdings iShares Russell Mid-Cap Value ETF 5.4 % Fairfax Financial Holdings, Ltd. (Canada) 4.6 % Willis Towers Watson PLC (United Kingdom) 4.5 % Talen Energy Corp. 4.2 % Lululemon Athletica, Inc. (Canada) 3.9 % Lithia Motors, Inc. 3.9 % Labcorp Holdings, Inc. 3.5 % BJ's Wholesale Club Holdings, Inc. 3.5 % The Kroger Co. 3.2 % Expedia Group, Inc. 2.6 % Top Ten as a Group 39.3 % |
| C000003030 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG River Road Mid Cap Value Fund |
| Class Name | Class I |
| Trading Symbol | ABMIX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG River Road Mid Cap Value Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG River Road Mid Cap Value Fund $ 0.81 % |
| Expenses Paid, Amount | $ 93 |
| Expense Ratio, Percent | 0.81% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • ® Top Contributors and Detractors • • • • • Positioning • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted over a ten year period, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-, five-, and ten-year periods ended as of October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years 10 Years Class I 29.27 % 12.77 % 7.70 % S&P 500 ® 38.02 % 15.27 % 13.00 % Russell Midcap ® 34.03 % 9.93 % 8.43 % |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 337,940,393 |
| Holdings Count | Holding | 46 |
| Advisory Fees Paid, Amount | $ 1,803,356 |
| Investment Company Portfolio Turnover | 77% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 46 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 77 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund and country allocation is shown as a percentage of total long-term investments of the Fund. Top Ten Holdings iShares Russell Mid-Cap Value ETF 5.4 % Fairfax Financial Holdings, Ltd. (Canada) 4.6 % Willis Towers Watson PLC (United Kingdom) 4.5 % Talen Energy Corp. 4.2 % Lululemon Athletica, Inc. (Canada) 3.9 % Lithia Motors, Inc. 3.9 % Labcorp Holdings, Inc. 3.5 % BJ's Wholesale Club Holdings, Inc. 3.5 % The Kroger Co. 3.2 % Expedia Group, Inc. 2.6 % Top Ten as a Group 39.3 % Portfolio Breakdown |
| Largest Holdings [Text Block] | Top Ten Holdings iShares Russell Mid-Cap Value ETF 5.4 % Fairfax Financial Holdings, Ltd. (Canada) 4.6 % Willis Towers Watson PLC (United Kingdom) 4.5 % Talen Energy Corp. 4.2 % Lululemon Athletica, Inc. (Canada) 3.9 % Lithia Motors, Inc. 3.9 % Labcorp Holdings, Inc. 3.5 % BJ's Wholesale Club Holdings, Inc. 3.5 % The Kroger Co. 3.2 % Expedia Group, Inc. 2.6 % Top Ten as a Group 39.3 % |
| C000194566 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG River Road Mid Cap Value Fund |
| Class Name | Class Z |
| Trading Symbol | ABIZX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG River Road Mid Cap Value Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG River Road Mid Cap Value Fund $ 0.76 % |
| Expenses Paid, Amount | $ 87 |
| Expense Ratio, Percent | 0.76% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • ® Top Contributors and Detractors • • • • • Positioning • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted since the class's inception on September 29, 2017, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-year and five-year periods and the period from the class's inception through October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years Since Inception Class Z 29.37 % 12.83 % 8.03 % S&P 500 ® 38.02 % 15.27 % 14.16 % Russell Midcap ® 34.03 % 9.93 % 8.52 % |
| Performance Inception Date | Sep. 29, 2017 |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 337,940,393 |
| Holdings Count | Holding | 46 |
| Advisory Fees Paid, Amount | $ 1,803,356 |
| Investment Company Portfolio Turnover | 77% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 46 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 77 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund and country allocation is shown as a percentage of total long-term investments of the Fund. Top Ten Holdings iShares Russell Mid-Cap Value ETF 5.4 % Fairfax Financial Holdings, Ltd. (Canada) 4.6 % Willis Towers Watson PLC (United Kingdom) 4.5 % Talen Energy Corp. 4.2 % Lululemon Athletica, Inc. (Canada) 3.9 % Lithia Motors, Inc. 3.9 % Labcorp Holdings, Inc. 3.5 % BJ's Wholesale Club Holdings, Inc. 3.5 % The Kroger Co. 3.2 % Expedia Group, Inc. 2.6 % Top Ten as a Group 39.3 % Portfolio Breakdown |
| Largest Holdings [Text Block] | Top Ten Holdings iShares Russell Mid-Cap Value ETF 5.4 % Fairfax Financial Holdings, Ltd. (Canada) 4.6 % Willis Towers Watson PLC (United Kingdom) 4.5 % Talen Energy Corp. 4.2 % Lululemon Athletica, Inc. (Canada) 3.9 % Lithia Motors, Inc. 3.9 % Labcorp Holdings, Inc. 3.5 % BJ's Wholesale Club Holdings, Inc. 3.5 % The Kroger Co. 3.2 % Expedia Group, Inc. 2.6 % Top Ten as a Group 39.3 % |
| C000003037 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG River Road Dividend All Cap Value Fund |
| Class Name | Class N |
| Trading Symbol | ARDEX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG River Road Dividend All Cap Value Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG River Road Dividend All Cap Value Fund $ 0.97 % |
| Expenses Paid, Amount | $ 112 |
| Expense Ratio, Percent | 0.97% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • • ® Relative Performance • ® Top Contributors and Detractors • • • • Positioning • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted over a ten year period, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-, five-, and ten-year periods ended as of October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years 10 Years Class N 31.94 % 7.64 % 7.21 % S&P 500 ® 38.02 % 15.27 % 13.00 % Russell 3000 ® 31.02 % 10.04 % 8.77 % |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 85,304,165 |
| Holdings Count | Holding | 57 |
| Advisory Fees Paid, Amount | $ 519,687 |
| Investment Company Portfolio Turnover | 26% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 57 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 26 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund. Top Ten Holdings Oracle Corp. 4.6 % The Williams Cos., Inc. 4.3 % Kinder Morgan, Inc. 3.8 % The Progressive Corp. 3.6 % The PNC Financial Services Group, Inc. 3.2 % Comcast Corp., Class A 3.2 % Unilever PLC, Sponsored ADR (United Kingdom) 3.1 % Corning, Inc. 3.1 % Cogent Communications Holdings, Inc. 3.1 % American Tower Corp., REIT 2.7 % Top Ten as a Group 34.7 % Portfolio Breakdown |
| Largest Holdings [Text Block] | Top Ten Holdings Oracle Corp. 4.6 % The Williams Cos., Inc. 4.3 % Kinder Morgan, Inc. 3.8 % The Progressive Corp. 3.6 % The PNC Financial Services Group, Inc. 3.2 % Comcast Corp., Class A 3.2 % Unilever PLC, Sponsored ADR (United Kingdom) 3.1 % Corning, Inc. 3.1 % Cogent Communications Holdings, Inc. 3.1 % American Tower Corp., REIT 2.7 % Top Ten as a Group 34.7 % |
| C000050291 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG River Road Dividend All Cap Value Fund |
| Class Name | Class I |
| Trading Symbol | ARIDX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG River Road Dividend All Cap Value Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG River Road Dividend All Cap Value Fund $ 0.72 % |
| Expenses Paid, Amount | $ 84 |
| Expense Ratio, Percent | 0.72% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • • ® Relative Performance • ® Top Contributors and Detractors • • • • Positioning • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted over a ten year period, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-, five-, and ten-year periods ended as of October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years 10 Years Class I 32.19 % 7.91 % 7.48 % S&P 500 ® 38.02 % 15.27 % 13.00 % Russell 3000 ® 31.02 % 10.04 % 8.77 % |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 85,304,165 |
| Holdings Count | Holding | 57 |
| Advisory Fees Paid, Amount | $ 519,687 |
| Investment Company Portfolio Turnover | 26% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 57 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 26 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund. Top Ten Holdings Oracle Corp. 4.6 % The Williams Cos., Inc. 4.3 % Kinder Morgan, Inc. 3.8 % The Progressive Corp. 3.6 % The PNC Financial Services Group, Inc. 3.2 % Comcast Corp., Class A 3.2 % Unilever PLC, Sponsored ADR (United Kingdom) 3.1 % Corning, Inc. 3.1 % Cogent Communications Holdings, Inc. 3.1 % American Tower Corp., REIT 2.7 % Top Ten as a Group 34.7 % Portfolio Breakdown |
| Largest Holdings [Text Block] | Top Ten Holdings Oracle Corp. 4.6 % The Williams Cos., Inc. 4.3 % Kinder Morgan, Inc. 3.8 % The Progressive Corp. 3.6 % The PNC Financial Services Group, Inc. 3.2 % Comcast Corp., Class A 3.2 % Unilever PLC, Sponsored ADR (United Kingdom) 3.1 % Corning, Inc. 3.1 % Cogent Communications Holdings, Inc. 3.1 % American Tower Corp., REIT 2.7 % Top Ten as a Group 34.7 % |
| C000194567 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG River Road Dividend All Cap Value Fund |
| Class Name | Class Z |
| Trading Symbol | ARZDX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG River Road Dividend All Cap Value Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG River Road Dividend All Cap Value Fund $ 0.68 % |
| Expenses Paid, Amount | $ 79 |
| Expense Ratio, Percent | 0.68% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • • ® Relative Performance • ® Top Contributors and Detractors • • • • Positioning • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted since the class's inception on September 29, 2017, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-year and five-year periods and the period from the class's inception through October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years Since Inception Class Z 32.37 % 7.98 % 7.49 % S&P 500 ® 38.02 % 15.27 % 14.16 % Russell 3000 ® 31.02 % 10.04 % 9.05 % |
| Performance Inception Date | Sep. 29, 2017 |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 85,304,165 |
| Holdings Count | Holding | 57 |
| Advisory Fees Paid, Amount | $ 519,687 |
| Investment Company Portfolio Turnover | 26% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 57 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 26 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund. Top Ten Holdings Oracle Corp. 4.6 % The Williams Cos., Inc. 4.3 % Kinder Morgan, Inc. 3.8 % The Progressive Corp. 3.6 % The PNC Financial Services Group, Inc. 3.2 % Comcast Corp., Class A 3.2 % Unilever PLC, Sponsored ADR (United Kingdom) 3.1 % Corning, Inc. 3.1 % Cogent Communications Holdings, Inc. 3.1 % American Tower Corp., REIT 2.7 % Top Ten as a Group 34.7 % Portfolio Breakdown |
| Largest Holdings [Text Block] | Top Ten Holdings Oracle Corp. 4.6 % The Williams Cos., Inc. 4.3 % Kinder Morgan, Inc. 3.8 % The Progressive Corp. 3.6 % The PNC Financial Services Group, Inc. 3.2 % Comcast Corp., Class A 3.2 % Unilever PLC, Sponsored ADR (United Kingdom) 3.1 % Corning, Inc. 3.1 % Cogent Communications Holdings, Inc. 3.1 % American Tower Corp., REIT 2.7 % Top Ten as a Group 34.7 % |
| C000003038 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG River Road Small Cap Value Fund |
| Class Name | Class N |
| Trading Symbol | ARSVX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG River Road Small Cap Value Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG River Road Small Cap Value Fund $ 1.37 % |
| Expenses Paid, Amount | $ 150 |
| Expense Ratio, Percent | 1.37% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • ® Top Contributors and Detractors • • • • • Positioning • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted over a ten year period, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-, five-, and ten-year periods ended as of October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years 10 Years Class N 18.69 % 8.69 % 9.45 % S&P 500 ® 38.02 % 15.27 % 13.00 % Russell 2000 ® 31.77 % 8.42 % 7.33 % |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 1,085,780,399 |
| Holdings Count | Holding | 63 |
| Advisory Fees Paid, Amount | $ 8,114,815 |
| Investment Company Portfolio Turnover | 42% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 63 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 42 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund. Top Ten Holdings White Mountains Insurance Group, Ltd. 4.1 % McGrath RentCorp 3.6 % Talen Energy Corp. 3.3 % Murphy USA, Inc. 3.0 % UniFirst Corp. 2.9 % Summit Materials, Inc., Class A 2.9 % Axis Capital Holdings, Ltd. (Bermuda) 2.7 % CoreCivic, Inc. 2.4 % The GEO Group Inc. 2.4 % Genworth Financial, Inc., Class A 2.3 % Top Ten as a Group 29.6 % Portfolio Breakdown |
| Largest Holdings [Text Block] | Top Ten Holdings White Mountains Insurance Group, Ltd. 4.1 % McGrath RentCorp 3.6 % Talen Energy Corp. 3.3 % Murphy USA, Inc. 3.0 % UniFirst Corp. 2.9 % Summit Materials, Inc., Class A 2.9 % Axis Capital Holdings, Ltd. (Bermuda) 2.7 % CoreCivic, Inc. 2.4 % The GEO Group Inc. 2.4 % Genworth Financial, Inc., Class A 2.3 % Top Ten as a Group 29.6 % |
| C000040086 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG River Road Small Cap Value Fund |
| Class Name | Class I |
| Trading Symbol | ARSIX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG River Road Small Cap Value Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG River Road Small Cap Value Fund $ 1.11 % |
| Expenses Paid, Amount | $ 122 |
| Expense Ratio, Percent | 1.11% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • ® Top Contributors and Detractors • • • • • Positioning • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted over a ten year period, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-, five-, and ten-year periods ended as of October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years 10 Years Class I 19.02 % 8.96 % 9.73 % S&P 500 ® 38.02 % 15.27 % 13.00 % Russell 2000 ® 31.77 % 8.42 % 7.33 % |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 1,085,780,399 |
| Holdings Count | Holding | 63 |
| Advisory Fees Paid, Amount | $ 8,114,815 |
| Investment Company Portfolio Turnover | 42% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 63 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 42 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund. Top Ten Holdings White Mountains Insurance Group, Ltd. 4.1 % McGrath RentCorp 3.6 % Talen Energy Corp. 3.3 % Murphy USA, Inc. 3.0 % UniFirst Corp. 2.9 % Summit Materials, Inc., Class A 2.9 % Axis Capital Holdings, Ltd. (Bermuda) 2.7 % CoreCivic, Inc. 2.4 % The GEO Group Inc. 2.4 % Genworth Financial, Inc., Class A 2.3 % Top Ten as a Group 29.6 % Portfolio Breakdown |
| Largest Holdings [Text Block] | Top Ten Holdings White Mountains Insurance Group, Ltd. 4.1 % McGrath RentCorp 3.6 % Talen Energy Corp. 3.3 % Murphy USA, Inc. 3.0 % UniFirst Corp. 2.9 % Summit Materials, Inc., Class A 2.9 % Axis Capital Holdings, Ltd. (Bermuda) 2.7 % CoreCivic, Inc. 2.4 % The GEO Group Inc. 2.4 % Genworth Financial, Inc., Class A 2.3 % Top Ten as a Group 29.6 % |
| C000194568 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG River Road Small Cap Value Fund |
| Class Name | Class Z |
| Trading Symbol | ARZMX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG River Road Small Cap Value Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG River Road Small Cap Value Fund $ 1.02 % |
| Expenses Paid, Amount | $ 112 |
| Expense Ratio, Percent | 1.02% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • ® Top Contributors and Detractors • • • • • Positioning • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted since the class's inception on September 29, 2017, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-year and five-year periods and the period from the class's inception through October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years Since Inception Class Z 19.07 % 9.07 % 8.78 % S&P 500 ® 38.02 % 15.27 % 14.16 % Russell 2000 ® 31.77 % 8.42 % 6.28 % |
| Performance Inception Date | Sep. 29, 2017 |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 1,085,780,399 |
| Holdings Count | Holding | 63 |
| Advisory Fees Paid, Amount | $ 8,114,815 |
| Investment Company Portfolio Turnover | 42% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 63 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 42 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund. White Mountains Insurance Group, Ltd. 4.1 % McGrath RentCorp 3.6 % Talen Energy Corp. 3.3 % Murphy USA, Inc. 3.0 % UniFirst Corp. 2.9 % Summit Materials, Inc., Class A 2.9 % Axis Capital Holdings, Ltd. (Bermuda) 2.7 % CoreCivic, Inc. 2.4 % The GEO Group Inc. 2.4 % Genworth Financial, Inc., Class A 2.3 % Top Ten as a Group 29.6 % Portfolio Breakdown |
| Largest Holdings [Text Block] | Top Ten Holdings White Mountains Insurance Group, Ltd. 4.1 % McGrath RentCorp 3.6 % Talen Energy Corp. 3.3 % Murphy USA, Inc. 3.0 % UniFirst Corp. 2.9 % Summit Materials, Inc., Class A 2.9 % Axis Capital Holdings, Ltd. (Bermuda) 2.7 % CoreCivic, Inc. 2.4 % The GEO Group Inc. 2.4 % Genworth Financial, Inc., Class A 2.3 % Top Ten as a Group 29.6 % |
| C000046749 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG River Road Small-Mid Cap Value Fund |
| Class Name | Class N |
| Trading Symbol | ARSMX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG River Road Small-Mid Cap Value Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG River Road Small-Mid Cap Value Fund $ 1.29 % |
| Expenses Paid, Amount | $ 143 |
| Expense Ratio, Percent | 1.29% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • ® Top Contributors and Detractors • • • • • Positioning Update • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted over a ten year period, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-, five-, and ten-year periods ended as of October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years 10 Years Class N 21.83 % 8.67 % 9.89 % S&P 500 ® 38.02 % 15.27 % 13.00 % Russell 2500 ® 32.42 % 9.39 % 7.87 % |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 319,835,913 |
| Holdings Count | Holding | 72 |
| Advisory Fees Paid, Amount | $ 2,250,580 |
| Investment Company Portfolio Turnover | 42% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 72 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 42 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund and country allocation is shown as a percentage of total long-term investments of the Fund. Top Ten Holdings BJ's Wholesale Club Holdings, Inc. 3.8 % White Mountains Insurance Group, Ltd. 3.6 % Murphy USA, Inc. 3.2 % McGrath RentCorp 3.2 % Talen Energy Corp. 3.0 % Lithia Motors, Inc. 2.8 % UniFirst Corp. 2.8 % TD SYNNEX Corp. 2.5 % WEX, Inc. 2.4 % LKQ Corp. 2.2 % Top Ten as a Group 29.5 % Portfolio Breakdown Country Allocation |
| Largest Holdings [Text Block] | Top Ten Holdings BJ's Wholesale Club Holdings, Inc. 3.8 % White Mountains Insurance Group, Ltd. 3.6 % Murphy USA, Inc. 3.2 % McGrath RentCorp 3.2 % Talen Energy Corp. 3.0 % Lithia Motors, Inc. 2.8 % UniFirst Corp. 2.8 % TD SYNNEX Corp. 2.5 % WEX, Inc. 2.4 % LKQ Corp. 2.2 % Top Ten as a Group 29.5 % |
| C000050292 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG River Road Small-Mid Cap Value Fund |
| Class Name | Class I |
| Trading Symbol | ARIMX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG River Road Small-Mid Cap Value Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG River Road Small-Mid Cap Value Fund $ 1.03 % |
| Expenses Paid, Amount | $ 114 |
| Expense Ratio, Percent | 1.03% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • ® Top Contributors and Detractors • • • • • Positioning Update • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted over a ten year period, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-, five-, and ten-year periods ended as of October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years 10 Years Class I 21.97 % 8.93 % 10.15 % S&P 500 ® 38.02 % 15.27 % 13.00 % Russell 2500 ® 32.42 % 9.39 % 7.87 % |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 319,835,913 |
| Holdings Count | Holding | 72 |
| Advisory Fees Paid, Amount | $ 2,250,580 |
| Investment Company Portfolio Turnover | 42% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 72 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 42 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund and country allocation is shown as a percentage of total long-term investments of the Fund. Top Ten Holdings BJ's Wholesale Club Holdings, Inc. 3.8 % White Mountains Insurance Group, Ltd. 3.6 % Murphy USA, Inc. 3.2 % McGrath RentCorp 3.2 % Talen Energy Corp. 3.0 % Lithia Motors, Inc. 2.8 % UniFirst Corp. 2.8 % TD SYNNEX Corp. 2.5 % WEX, Inc. 2.4 % LKQ Corp. 2.2 % Top Ten as a Group 29.5 % Portfolio Breakdown Country Allocation |
| Largest Holdings [Text Block] | Top Ten Holdings BJ's Wholesale Club Holdings, Inc. 3.8 % White Mountains Insurance Group, Ltd. 3.6 % Murphy USA, Inc. 3.2 % McGrath RentCorp 3.2 % Talen Energy Corp. 3.0 % Lithia Motors, Inc. 2.8 % UniFirst Corp. 2.8 % TD SYNNEX Corp. 2.5 % WEX, Inc. 2.4 % LKQ Corp. 2.2 % Top Ten as a Group 29.5 % |
| C000194569 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG River Road Small-Mid Cap Value Fund |
| Class Name | Class Z |
| Trading Symbol | ARSZX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG River Road Small-Mid Cap Value Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG River Road Small-Mid Cap Value Fund $ 0.98 % |
| Expenses Paid, Amount | $ 109 |
| Expense Ratio, Percent | 0.98% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • ® Top Contributors and Detractors • • • • • Positioning Update • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted since the class's inception on September 29, 2017, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-year and five-year periods and the period from the class's inception through October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years Since Inception Class Z 22.13 % 9.00 % 8.91 % S&P 500 ® 38.02 % 15.27 % 14.16 % Russell 2500 ® 32.42 % 9.39 % 7.56 % |
| Performance Inception Date | Sep. 29, 2017 |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 319,835,913 |
| Holdings Count | Holding | 72 |
| Advisory Fees Paid, Amount | $ 2,250,580 |
| Investment Company Portfolio Turnover | 42% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 72 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 42 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund and country allocation is shown as a percentage of total long-term investments of the Fund. Top Ten Holdings BJ's Wholesale Club Holdings, Inc. 3.8 % White Mountains Insurance Group, Ltd. 3.6 % Murphy USA, Inc. 3.2 % McGrath RentCorp 3.2 % Talen Energy Corp. 3.0 % Lithia Motors, Inc. 2.8 % UniFirst Corp. 2.8 % TD SYNNEX Corp. 2.5 % WEX, Inc. 2.4 % LKQ Corp. 2.2 % Top Ten as a Group 29.5 % Portfolio Breakdown Country Allocation |
| Largest Holdings [Text Block] | Top Ten Holdings BJ's Wholesale Club Holdings, Inc. 3.8 % White Mountains Insurance Group, Ltd. 3.6 % Murphy USA, Inc. 3.2 % McGrath RentCorp 3.2 % Talen Energy Corp. 3.0 % Lithia Motors, Inc. 2.8 % UniFirst Corp. 2.8 % TD SYNNEX Corp. 2.5 % WEX, Inc. 2.4 % LKQ Corp. 2.2 % Top Ten as a Group 29.5 % |
| C000092914 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG GW&K Small/Mid Cap Growth Fund |
| Class Name | Class N |
| Trading Symbol | ACWDX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG GW&K Small/Mid Cap Growth Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG GW&K Small/Mid Cap Growth Fund $ 1.01 % |
| Expenses Paid, Amount | $ 115 |
| Expense Ratio, Percent | 1.01% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • ® ® • Top Contributors and Detractors • • • • • • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted over a ten year period, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-, five-, and ten-year periods ended as of October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years 10 Years Class N 28.36 % 12.48 % 7.97 % S&P 500 ® 38.02 % 15.27 % 13.00 % Russell 2500 ® 34.21 % 9.14 % 9.48 % |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 41,834,206 |
| Holdings Count | Holding | 77 |
| Advisory Fees Paid, Amount | $ 157,451 |
| Investment Company Portfolio Turnover | 19% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 77 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 19 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund. Top Ten Holdings CyberArk Software, Ltd. (Israel) 2.5 % Texas Roadhouse, Inc. 2.2 % Tyler Technologies, Inc. 2.1 % Houlihan Lokey, Inc. 2.1 % ITT, Inc. 1.9 % CACI International, Inc., Class A 1.9 % Burlington Stores, Inc. 1.9 % Entegris, Inc. 1.9 % Globant SA (Uruguay) 1.9 % Manhattan Associates, Inc. 1.8 % Top Ten as a Group 20.2 % Portfolio Breakdown |
| Largest Holdings [Text Block] | Top Ten Holdings CyberArk Software, Ltd. (Israel) 2.5 % Texas Roadhouse, Inc. 2.2 % Tyler Technologies, Inc. 2.1 % Houlihan Lokey, Inc. 2.1 % ITT, Inc. 1.9 % CACI International, Inc., Class A 1.9 % Burlington Stores, Inc. 1.9 % Entegris, Inc. 1.9 % Globant SA (Uruguay) 1.9 % Manhattan Associates, Inc. 1.8 % Top Ten as a Group 20.2 % |
| C000101741 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG GW&K Small/Mid Cap Growth Fund |
| Class Name | Class I |
| Trading Symbol | ACWIX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG GW&K Small/Mid Cap Growth Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG GW&K Small/Mid Cap Growth Fund $ 0.87 % |
| Expenses Paid, Amount | $ 99 |
| Expense Ratio, Percent | 0.87% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • ® ® • Top Contributors and Detractors • • • • • • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted over a ten year period, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-, five-, and ten-year periods ended as of October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years 10 Years Class I 28.43 % 12.65 % 8.17 % S&P 500 ® 38.02 % 15.27 % 13.00 % Russell 2500 ® 34.21 % 9.14 % 9.48 % |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 41,834,206 |
| Holdings Count | Holding | 77 |
| Advisory Fees Paid, Amount | $ 157,451 |
| Investment Company Portfolio Turnover | 19% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 77 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 19 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund. Top Ten Holdings CyberArk Software, Ltd. (Israel) 2.5 % Texas Roadhouse, Inc. 2.2 % Tyler Technologies, Inc. 2.1 % Houlihan Lokey, Inc. 2.1 % ITT, Inc. 1.9 % CACI International, Inc., Class A 1.9 % Burlington Stores, Inc. 1.9 % Entegris, Inc. 1.9 % Globant SA (Uruguay) 1.9 % Manhattan Associates, Inc. 1.8 % Top Ten as a Group 20.2 % Portfolio Breakdown |
| Largest Holdings [Text Block] | Top Ten Holdings CyberArk Software, Ltd. (Israel) 2.5 % Texas Roadhouse, Inc. 2.2 % Tyler Technologies, Inc. 2.1 % Houlihan Lokey, Inc. 2.1 % ITT, Inc. 1.9 % CACI International, Inc., Class A 1.9 % Burlington Stores, Inc. 1.9 % Entegris, Inc. 1.9 % Globant SA (Uruguay) 1.9 % Manhattan Associates, Inc. 1.8 % Top Ten as a Group 20.2 % |
| C000230346 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG GW&K Small/Mid Cap Growth Fund |
| Class Name | Class Z |
| Trading Symbol | ACWZX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG GW&K Small/Mid Cap Growth Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG GW&K Small/Mid Cap Growth Fund $ 0.82 % |
| Expenses Paid, Amount | $ 94 |
| Expense Ratio, Percent | 0.82% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • ® ® • Top Contributors and Detractors • • • • • • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted since the class's inception on August 31, 2021, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-year period Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year Since Inception Class Z 28.53 % 0.77 % S&P 500 ® 38.02 % 9.28 % Russell 2500 ® 34.21 % (1.99 % ) |
| Performance Inception Date | Aug. 31, 2021 |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 41,834,206 |
| Holdings Count | Holding | 77 |
| Advisory Fees Paid, Amount | $ 157,451 |
| Investment Company Portfolio Turnover | 19% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 77 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 19 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund. Top Ten Holdings CyberArk Software, Ltd. (Israel) 2.5 % Texas Roadhouse, Inc. 2.2 % Tyler Technologies, Inc. 2.1 % Houlihan Lokey, Inc. 2.1 % ITT, Inc. 1.9 % CACI International, Inc., Class A 1.9 % Burlington Stores, Inc. 1.9 % Entegris, Inc. 1.9 % Globant SA (Uruguay) 1.9 % Manhattan Associates, Inc. 1.8 % Top Ten as a Group 20.2 % Portfolio Breakdown |
| Largest Holdings [Text Block] | Top Ten Holdings CyberArk Software, Ltd. (Israel) 2.5 % Texas Roadhouse, Inc. 2.2 % Tyler Technologies, Inc. 2.1 % Houlihan Lokey, Inc. 2.1 % ITT, Inc. 1.9 % CACI International, Inc., Class A 1.9 % Burlington Stores, Inc. 1.9 % Entegris, Inc. 1.9 % Globant SA (Uruguay) 1.9 % Manhattan Associates, Inc. 1.8 % Top Ten as a Group 20.2 % |
| C000102286 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG Beutel Goodman Core Plus Bond Fund |
| Class Name | Class N |
| Trading Symbol | ADBLX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG Beutel Goodman Core Plus Bond Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG Beutel Goodman Core Plus Bond Fund $ 0.68 % |
| Expenses Paid, Amount | $ 72 |
| Expense Ratio, Percent | 0.68% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • • Top Contributors and Detractors • • • Positioning Update • • • • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted over a ten year period, as compared to the performance of a Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years 10 Years Class N 10.97 % (0.62 % ) 1.22 % Bloomberg U.S. Aggregate Bond Index 10.55 % (0.23 % ) 1.49 % |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 121,038,761 |
| Holdings Count | Holding | 110 |
| Advisory Fees Paid, Amount | $ 141,598 |
| Investment Company Portfolio Turnover | 83% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 110 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 83 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund and ratings are shown as a percentage of total long-term investments of the Fund. Top Ten Holdings U.S. Treasury Notes, 4.500%, 11/15/33 9.4 % U.S. Treasury Bonds, 4.250%, 02/15/54 4.4 % U.S. Treasury Notes, 3.500%, 09/30/29 3.5 % FNMA, 2.140%, 10/01/29 3.5 % FNMA, 3.000%, 06/01/52 3.5 % U.S. Treasury Bonds, 3.000%, 08/15/52 2.8 % U.S. Treasury Bonds, 1.875%, 02/15/41 2.8 % Bank of America Corp., 4.376%, 04/27/28 2.5 % FNMA, 2.260%, 01/01/30 2.4 % U.S. Treasury Notes, 3.500%, 02/15/33 2.2 % Top Ten as a Group 37.0 % Portfolio Breakdown Ratings |
| Largest Holdings [Text Block] | Top Ten Holdings U.S. Treasury Notes, 4.500%, 11/15/33 9.4 % U.S. Treasury Bonds, 4.250%, 02/15/54 4.4 % U.S. Treasury Notes, 3.500%, 09/30/29 3.5 % FNMA, 2.140%, 10/01/29 3.5 % FNMA, 3.000%, 06/01/52 3.5 % U.S. Treasury Bonds, 3.000%, 08/15/52 2.8 % U.S. Treasury Bonds, 1.875%, 02/15/41 2.8 % Bank of America Corp., 4.376%, 04/27/28 2.5 % FNMA, 2.260%, 01/01/30 2.4 % U.S. Treasury Notes, 3.500%, 02/15/33 2.2 % Top Ten as a Group 37.0 % |
| C000102287 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG Beutel Goodman Core Plus Bond Fund |
| Class Name | Class I |
| Trading Symbol | ADLIX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG Beutel Goodman Core Plus Bond Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG Beutel Goodman Core Plus Bond Fund $ 0.48 % |
| Expenses Paid, Amount | $ 51 |
| Expense Ratio, Percent | 0.48% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • • Top Contributors and Detractors • • • Positioning Update • • • • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted over a ten year period, as compared to the performance of a Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years 10 Years Class I 11.21 % (0.42 % ) 1.45 % Bloomberg U.S. Aggregate Bond Index 10.55 % (0.23 % ) 1.49 % |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 121,038,761 |
| Holdings Count | Holding | 110 |
| Advisory Fees Paid, Amount | $ 141,598 |
| Investment Company Portfolio Turnover | 83% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 110 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 83 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund and ratings are shown as a percentage of total long-term investments of the Fund. Top Ten Holdings U.S. Treasury Notes, 4.500%, 11/15/33 9.4 % U.S. Treasury Bonds, 4.250%, 02/15/54 4.4 % U.S. Treasury Notes, 3.500%, 09/30/29 3.5 % FNMA, 2.140%, 10/01/29 3.5 % FNMA, 3.000%, 06/01/52 3.5 % U.S. Treasury Bonds, 3.000%, 08/15/52 2.8 % U.S. Treasury Bonds, 1.875%, 02/15/41 2.8 % Bank of America Corp., 4.376%, 04/27/28 2.5 % FNMA, 2.260%, 01/01/30 2.4 % U.S. Treasury Notes, 3.500%, 02/15/33 2.2 % Top Ten as a Group 37.0 % Portfolio Breakdown Ratings |
| Largest Holdings [Text Block] | Top Ten Holdings U.S. Treasury Notes, 4.500%, 11/15/33 9.4 % U.S. Treasury Bonds, 4.250%, 02/15/54 4.4 % U.S. Treasury Notes, 3.500%, 09/30/29 3.5 % FNMA, 2.140%, 10/01/29 3.5 % FNMA, 3.000%, 06/01/52 3.5 % U.S. Treasury Bonds, 3.000%, 08/15/52 2.8 % U.S. Treasury Bonds, 1.875%, 02/15/41 2.8 % Bank of America Corp., 4.376%, 04/27/28 2.5 % FNMA, 2.260%, 01/01/30 2.4 % U.S. Treasury Notes, 3.500%, 02/15/33 2.2 % Top Ten as a Group 37.0 % |
| C000194571 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG Beutel Goodman Core Plus Bond Fund |
| Class Name | Class Z |
| Trading Symbol | ADZIX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG Beutel Goodman Core Plus Bond Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG Beutel Goodman Core Plus Bond Fund $ 0.43 % |
| Expenses Paid, Amount | $ 45 |
| Expense Ratio, Percent | 0.43% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • • Top Contributors and Detractors • • • Positioning Update • • • • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted since the class's inception on September 29, 2017, as compared to the performance of a Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years Since Inception Class Z 11.25 % (0.34 % ) 0.87 % Bloomberg U.S. Aggregate Bond Index 10.55 % (0.23 % ) 1.10 % |
| Performance Inception Date | Sep. 29, 2017 |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 121,038,761 |
| Holdings Count | Holding | 110 |
| Advisory Fees Paid, Amount | $ 141,598 |
| Investment Company Portfolio Turnover | 83% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 110 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 83 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund and ratings are shown as a percentage of total long-term investments of the Fund. Top Ten Holdings U.S. Treasury Notes, 4.500%, 11/15/33 9.4 % U.S. Treasury Bonds, 4.250%, 02/15/54 4.4 % U.S. Treasury Notes, 3.500%, 09/30/29 3.5 % FNMA, 2.140%, 10/01/29 3.5 % FNMA, 3.000%, 06/01/52 3.5 % U.S. Treasury Bonds, 3.000%, 08/15/52 2.8 % U.S. Treasury Bonds, 1.875%, 02/15/41 2.8 % Bank of America Corp., 4.376%, 04/27/28 2.5 % FNMA, 2.260%, 01/01/30 2.4 % U.S. Treasury Notes, 3.500%, 02/15/33 2.2 % Top Ten as a Group 37.0 % Portfolio Breakdown Ratings |
| Largest Holdings [Text Block] | Top Ten Holdings U.S. Treasury Notes, 4.500%, 11/15/33 9.4 % U.S. Treasury Bonds, 4.250%, 02/15/54 4.4 % U.S. Treasury Notes, 3.500%, 09/30/29 3.5 % FNMA, 2.140%, 10/01/29 3.5 % FNMA, 3.000%, 06/01/52 3.5 % U.S. Treasury Bonds, 3.000%, 08/15/52 2.8 % U.S. Treasury Bonds, 1.875%, 02/15/41 2.8 % Bank of America Corp., 4.376%, 04/27/28 2.5 % FNMA, 2.260%, 01/01/30 2.4 % U.S. Treasury Notes, 3.500%, 02/15/33 2.2 % Top Ten as a Group 37.0 % |
| C000161968 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG River Road Focused Absolute Value Fund |
| Class Name | Class N |
| Trading Symbol | ARRFX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG River Road Focused Absolute Value Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG River Road Focused Absolute Value Fund $ 1.06 % |
| Expenses Paid, Amount | $ 121 |
| Expense Ratio, Percent | 1.06% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • ® • Top Contributors and Detractors • • • • • Positioning • • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted since the class's inception on November 02, 2015, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-year and five-year periods and the period from the class's inception through October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years Since Inception Class N 28.70 % 5.55 % 8.44 % S&P 500 ® 38.02 % 15.27 % 13.75 % Russell 3000 ® 31.02 % 10.04 % 9.59 % |
| Performance Inception Date | Nov. 02, 2015 |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 49,054,320 |
| Holdings Count | Holding | 33 |
| Advisory Fees Paid, Amount | $ 192,000 |
| Investment Company Portfolio Turnover | 86% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 33 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 86 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund. Top Ten Holdings Fairfax Financial Holdings, Ltd. (Canada) 6.6 % Berkshire Hathaway, Inc., Class B 6.0 % BJ's Wholesale Club Holdings, Inc. 5.0 % The Kroger Co. 4.9 % CRH PLC 4.5 % Papa John's International, Inc. 3.7 % Mid-America Apartment Communities, Inc., REIT 3.7 % Talen Energy Corp. 3.6 % Northwestern Energy Group, Inc. 3.4 % SS&C Technologies Holdings, Inc. 3.4 % Top Ten as a Group 44.8 % Portfolio Breakdown |
| Largest Holdings [Text Block] | Top Ten Holdings Fairfax Financial Holdings, Ltd. (Canada) 6.6 % Berkshire Hathaway, Inc., Class B 6.0 % BJ's Wholesale Club Holdings, Inc. 5.0 % The Kroger Co. 4.9 % CRH PLC 4.5 % Papa John's International, Inc. 3.7 % Mid-America Apartment Communities, Inc., REIT 3.7 % Talen Energy Corp. 3.6 % Northwestern Energy Group, Inc. 3.4 % SS&C Technologies Holdings, Inc. 3.4 % Top Ten as a Group 44.8 % |
| C000161967 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG River Road Focused Absolute Value Fund |
| Class Name | Class I |
| Trading Symbol | AFAVX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG River Road Focused Absolute Value Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG River Road Focused Absolute Value Fund $ 0.82 % |
| Expenses Paid, Amount | $ 94 |
| Expense Ratio, Percent | 0.82% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • ® • Top Contributors and Detractors • • • • • Positioning • • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted since the class's inception on November 02, 2015, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-year and five-year periods and the period from the class's inception through October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years Since Inception Class I 28.90 % 5.80 % 8.70 % S&P 500 ® 38.02 % 15.27 % 13.75 % Russell 3000 ® 31.02 % 10.04 % 9.59 % |
| Performance Inception Date | Nov. 02, 2015 |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 49,054,320 |
| Holdings Count | Holding | 33 |
| Advisory Fees Paid, Amount | $ 192,000 |
| Investment Company Portfolio Turnover | 86% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 33 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 86 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund. Top Ten Holdings Fairfax Financial Holdings, Ltd. (Canada) 6.6 % Berkshire Hathaway, Inc., Class B 6.0 % BJ's Wholesale Club Holdings, Inc. 5.0 % The Kroger Co. 4.9 % CRH PLC 4.5 % Papa John's International, Inc. 3.7 % Mid-America Apartment Communities, Inc., REIT 3.7 % Talen Energy Corp. 3.6 % Northwestern Energy Group, Inc. 3.4 % SS&C Technologies Holdings, Inc. 3.4 % Top Ten as a Group 44.8 % Portfolio Breakdown |
| Largest Holdings [Text Block] | Top Ten Holdings Fairfax Financial Holdings, Ltd. (Canada) 6.6 % Berkshire Hathaway, Inc., Class B 6.0 % BJ's Wholesale Club Holdings, Inc. 5.0 % The Kroger Co. 4.9 % CRH PLC 4.5 % Papa John's International, Inc. 3.7 % Mid-America Apartment Communities, Inc., REIT 3.7 % Talen Energy Corp. 3.6 % Northwestern Energy Group, Inc. 3.4 % SS&C Technologies Holdings, Inc. 3.4 % Top Ten as a Group 44.8 % |
| C000194575 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | AMG River Road Focused Absolute Value Fund |
| Class Name | Class Z |
| Trading Symbol | ARRZX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about AMG River Road Focused Absolute Value Fund (the “Fund”) for the period of November 1, 2023 to October 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://wealth.amg.com/resources/order-literature |
| Additional Information Phone Number | 800.548.4539 |
| Additional Information Website | https://wealth.amg.com/resources/order-literature |
| Expenses [Text Block] | Fund Expenses What were the Fund costs for the last year? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment AMG River Road Focused Absolute Value Fund $ 0.78 % |
| Expenses Paid, Amount | $ 89 |
| Expense Ratio, Percent | 0.78% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance Performance Overview • ® • Top Contributors and Detractors • • • • • Positioning • • |
| 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 performance line graph below shows the performance of a hypothetical $10,000 investment in the class of shares noted since the class's inception on September 29, 2017, as compared to the performance of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests. The performance table below shows the average annual total returns of the class of shares noted for the past one-year and five-year periods and the period from the class's inception through October 31, 2024. It also shows the average total returns of (i) a broad based index and (ii) an additional index reflecting the market segment(s) in which the Fund invests over the same periods. Performance for other share classes will vary. The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. GROWTH OF $10,000 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS 1 Year 5 Years Since Inception Class Z 29.04 % 5.84 % 7.08 % S&P 500 ® 38.02 % 15.27 % 14.16 % Russell 3000 ® 31.02 % 10.04 % 9.05 % |
| Performance Inception Date | Sep. 29, 2017 |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| Updated Performance Information Location [Text Block] | For updated Fund performance information, please visit: https://wealth.amg.com/ |
| Net Assets | $ 49,054,320 |
| Holdings Count | Holding | 33 |
| Advisory Fees Paid, Amount | $ 192,000 |
| Investment Company Portfolio Turnover | 86% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of Fund net assets $ Total number of portfolio holdings 33 Net advisory fees paid $ Portfolio turnover rate as of the end of the reporting period 86 % |
| Holdings [Text Block] | Graphical Representation of Holdings (as of October 31, 2024) Top ten holdings and portfolio breakdown are shown as a percentage of net assets of the Fund. Top Ten Holdings Fairfax Financial Holdings, Ltd. (Canada) 6.6 % Berkshire Hathaway, Inc., Class B 6.0 % BJ's Wholesale Club Holdings, Inc. 5.0 % The Kroger Co. 4.9 % CRH PLC 4.5 % Papa John's International, Inc. 3.7 % Mid-America Apartment Communities, Inc., REIT 3.7 % Talen Energy Corp. 3.6 % Northwestern Energy Group, Inc. 3.4 % SS&C Technologies Holdings, Inc. 3.4 % Top Ten as a Group 44.8 % Portfolio Breakdown |
| Largest Holdings [Text Block] | Top Ten Holdings Fairfax Financial Holdings, Ltd. (Canada) 6.6 % Berkshire Hathaway, Inc., Class B 6.0 % BJ's Wholesale Club Holdings, Inc. 5.0 % The Kroger Co. 4.9 % CRH PLC 4.5 % Papa John's International, Inc. 3.7 % Mid-America Apartment Communities, Inc., REIT 3.7 % Talen Energy Corp. 3.6 % Northwestern Energy Group, Inc. 3.4 % SS&C Technologies Holdings, Inc. 3.4 % Top Ten as a Group 44.8 % |
| Shareholder Report, Line Graph (Details) - USD ($) | 12 Months Ended | 38 Months Ended | 60 Months Ended | 85 Months Ended | 108 Months Ended | 120 Months Ended | ||||||||||||||||
| Oct. 31, 2024 | Oct. 31, 2024 | Oct. 31, 2024 | Oct. 31, 2024 | Oct. 31, 2024 | Oct. 31, 2024 | Apr. 30, 2024 | Oct. 31, 2023 | Apr. 30, 2023 | Oct. 31, 2022 | Apr. 30, 2022 | Oct. 31, 2021 | Aug. 31, 2021 | Oct. 31, 2020 | Oct. 31, 2019 | Oct. 31, 2018 | Oct. 31, 2017 | Sep. 29, 2017 | Oct. 31, 2016 | Nov. 02, 2015 | Oct. 31, 2015 | Oct. 31, 2014 | |
| C000003009 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class N | |||||||||||||||||||||
| Account Value | $ 30,781 | $ 30,781 | $ 30,781 | $ 30,781 | $ 30,781 | $ 30,781 | $ 23,837 | $ 20,350 | $ 27,198 | $ 19,497 | $ 16,066 | $ 13,581 | $ 12,509 | $ 10,602 | $ 10,793 | $ 10,000 | ||||||
| Average Annual Return, Percent | 29.13% | 13.89% | 11.90% | |||||||||||||||||||
| C000003010 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class I | |||||||||||||||||||||
| Account Value | $ 31,389 | 31,389 | $ 31,389 | 31,389 | 31,389 | $ 31,389 | 24,250 | 20,679 | 27,591 | 19,739 | 16,232 | 13,700 | 12,598 | 10,657 | 10,820 | 10,000 | ||||||
| Average Annual Return, Percent | 29.43% | 14.10% | 12.12% | |||||||||||||||||||
| C000003029 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class N | |||||||||||||||||||||
| Account Value | $ 20,447.3 | 20,447.3 | $ 20,447.3 | 20,447.3 | 20,447.3 | $ 20,447.3 | 15,859.9 | 14,769.2 | 15,656.5 | 10,392.6 | 11,372.2 | 11,435.7 | 11,767.6 | 10,069.3 | 9,498.14 | 10,000 | ||||||
| Average Annual Return, Percent | 28.92% | 12.45% | 7.41% | |||||||||||||||||||
| C000003030 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class I | |||||||||||||||||||||
| Account Value | $ 21,000.7 | 21,000.7 | $ 21,000.7 | 21,000.7 | 21,000.7 | $ 21,000.7 | 16,244.9 | 15,080 | 15,942.4 | 10,550.3 | 11,514.8 | 11,552.9 | 11,855.9 | 10,119 | 9,522.57 | 10,000 | ||||||
| Average Annual Return, Percent | 29.27% | 12.77% | 7.70% | |||||||||||||||||||
| C000194566 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class Z | |||||||||||||||||||||
| Account Value | $ 17,282.9 | 17,282.9 | $ 17,282.9 | $ 17,282.9 | 17,282.9 | $ 17,282.9 | 13,359.3 | 12,400.8 | 13,099.8 | 8,664.87 | 9,450.75 | 9,474.45 | 9,715.2 | $ 10,000 | ||||||||
| Average Annual Return, Percent | 29.37% | 12.83% | 8.03% | |||||||||||||||||||
| C000003037 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class N | |||||||||||||||||||||
| Account Value | $ 20,058 | 20,058 | $ 20,058 | $ 20,058 | 20,058 | $ 20,058 | 15,202 | 16,435 | 16,658 | 12,363 | 13,884 | 12,610 | 12,355 | 10,763 | 9,977 | 10,000 | ||||||
| Average Annual Return, Percent | 31.94% | 7.64% | 7.21% | |||||||||||||||||||
| C000050291 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class I | |||||||||||||||||||||
| Account Value | $ 20,567 | 20,567 | $ 20,567 | 20,567 | 20,567 | $ 20,567 | 15,560 | 16,762 | 16,962 | 12,556 | 14,059 | 12,744 | 12,448 | 10,817 | 10,002 | 10,000 | ||||||
| Average Annual Return, Percent | 32.19% | 7.91% | 7.48% | |||||||||||||||||||
| C000194567 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class Z | |||||||||||||||||||||
| Account Value | $ 16,686 | 16,686 | $ 16,686 | $ 16,686 | 16,686 | $ 16,686 | 12,607 | 13,588 | 13,742 | 10,160 | 11,370 | 10,302 | 10,059 | 10,000 | ||||||||
| Average Annual Return, Percent | 32.37% | 7.98% | 7.49% | |||||||||||||||||||
| C000003038 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class N | |||||||||||||||||||||
| Account Value | $ 24,658.15 | 24,658.15 | $ 24,658.15 | $ 24,658.15 | 24,658.15 | $ 24,658.15 | 20,776.98 | 20,453.49 | 20,525.12 | 14,294.52 | 16,261.19 | 14,667.89 | 13,915.57 | 11,273.78 | 10,514.68 | 10,000 | ||||||
| Average Annual Return, Percent | 18.69% | 8.69% | 9.45% | |||||||||||||||||||
| C000040086 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class I | |||||||||||||||||||||
| Account Value | $ 25,313.06 | 25,313.06 | $ 25,313.06 | 25,313.06 | 25,313.06 | $ 25,313.06 | 21,270.76 | 20,892.93 | 20,907.39 | 14,520.1 | 16,482.73 | 14,818.38 | 14,032.93 | 11,335.2 | 10,544.88 | 10,000 | ||||||
| Average Annual Return, Percent | 19.02% | 8.96% | 9.73% | |||||||||||||||||||
| C000194568 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class Z | |||||||||||||||||||||
| Account Value | $ 18,162.39 | 18,162.39 | $ 18,162.39 | $ 18,162.39 | 18,162.39 | $ 18,162.39 | 15,253.55 | 14,962.77 | 14,962.97 | 10,378.78 | 11,764.79 | 10,571.05 | 10,000 | 10,000 | ||||||||
| Average Annual Return, Percent | 19.07% | 9.07% | 8.78% | |||||||||||||||||||
| C000046749 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class N | |||||||||||||||||||||
| Account Value | $ 25,667 | 25,667 | $ 25,667 | $ 25,667 | 25,667 | $ 25,667 | 21,070 | 21,233 | 21,586 | 14,963 | 16,935 | 15,145 | 14,143 | 11,209 | 10,326 | 10,000 | ||||||
| Average Annual Return, Percent | 21.83% | 8.67% | 9.89% | |||||||||||||||||||
| C000050292 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class I | |||||||||||||||||||||
| Account Value | $ 26,299 | 26,299 | $ 26,299 | 26,299 | 26,299 | $ 26,299 | 21,562 | 21,665 | 21,968 | 15,181 | 17,147 | 15,294 | 14,252 | 11,254 | 10,360 | 10,000 | ||||||
| Average Annual Return, Percent | 21.97% | 8.93% | 10.15% | |||||||||||||||||||
| C000194569 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class Z | |||||||||||||||||||||
| Account Value | $ 18,307 | 18,307 | $ 18,307 | $ 18,307 | 18,307 | $ 18,307 | 14,991 | 15,062 | 15,254 | 10,537 | 11,898 | 10,598 | 9,870 | 10,000 | ||||||||
| Average Annual Return, Percent | 22.13% | 9% | 8.91% | |||||||||||||||||||
| C000092914 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class N | |||||||||||||||||||||
| Account Value | $ 21,532 | 21,532 | $ 21,532 | $ 21,532 | 21,532 | $ 21,532 | 16,775 | 16,589 | 21,794 | 14,860 | 11,958 | 11,874 | 10,750 | 8,565 | 10,165 | 10,000 | ||||||
| Average Annual Return, Percent | 28.36% | 12.48% | 7.97% | |||||||||||||||||||
| C000101741 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class I | |||||||||||||||||||||
| Account Value | $ 21,926 | 21,926 | $ 21,926 | 21,926 | 21,926 | $ 21,926 | 17,072 | 16,843 | 22,108 | 15,046 | 12,087 | 11,976 | 10,820 | 8,606 | 10,191 | 10,000 | ||||||
| Average Annual Return, Percent | 28.43% | 12.65% | 8.17% | |||||||||||||||||||
| C000230346 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class Z | |||||||||||||||||||||
| Account Value | $ 10,245 | $ 10,245 | $ 10,245 | 10,245 | 10,245 | $ 10,245 | $ 9,457 | 7,971 | $ 8,217 | 7,859 | $ 8,117 | 10,308 | $ 10,000 | |||||||||
| Average Annual Return, Percent | 28.53% | 0.77% | ||||||||||||||||||||
| C000102286 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class N | |||||||||||||||||||||
| Account Value | $ 11,284 | $ 11,284 | $ 11,284 | 11,284 | 11,284 | $ 11,284 | 10,169 | 10,239 | 12,250 | 11,988 | 11,638 | 10,710 | 10,854 | 10,571 | 10,104 | 10,000 | ||||||
| Average Annual Return, Percent | 10.97% | (0.62%) | 1.22% | |||||||||||||||||||
| C000102287 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class I | |||||||||||||||||||||
| Account Value | $ 11,543 | 11,543 | $ 11,543 | 11,543 | 11,543 | $ 11,543 | 10,380 | 10,442 | 12,456 | 12,158 | 11,784 | 10,818 | 10,925 | 10,612 | 10,128 | 10,000 | ||||||
| Average Annual Return, Percent | 11.21% | (0.42%) | 1.45% | |||||||||||||||||||
| C000194571 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class Z | |||||||||||||||||||||
| Account Value | $ 10,631 | 10,631 | $ 10,631 | $ 10,631 | 10,631 | $ 10,631 | 9,555 | 9,597 | 11,452 | 11,172 | 10,810 | 9,925 | 10,016 | 10,000 | ||||||||
| Average Annual Return, Percent | 11.25% | (0.34%) | 0.87% | |||||||||||||||||||
| C000161968 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class N | |||||||||||||||||||||
| Account Value | $ 20,731 | 20,731 | $ 20,731 | $ 20,731 | $ 20,731 | 20,731 | 16,109 | 15,676 | 18,399 | 14,080 | 15,825 | 13,846 | 12,740 | 10,850 | $ 10,000 | |||||||
| Average Annual Return, Percent | 28.70% | 5.55% | 8.44% | |||||||||||||||||||
| C000161967 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class I | |||||||||||||||||||||
| Account Value | $ 21,179 | 21,179 | $ 21,179 | 21,179 | $ 21,179 | 21,179 | 16,430 | 15,934 | 18,668 | 14,252 | 15,979 | 13,949 | 12,808 | 10,880 | 10,000 | |||||||
| Average Annual Return, Percent | 28.90% | 5.80% | 8.70% | |||||||||||||||||||
| C000194575 [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Class Z | |||||||||||||||||||||
| Account Value | $ 16,242 | 16,242 | $ 16,242 | $ 16,242 | $ 16,242 | 16,242 | 12,586 | 12,208 | 14,293 | 10,901 | 12,229 | 10,663 | 9,787 | 10,000 | ||||||||
| Average Annual Return, Percent | 29.04% | 5.84% | 7.08% | |||||||||||||||||||
| Standard & Poor's 500 Index [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | S&P 500® Index | |||||||||||||||||||||
| Account Value | $ 33,949 | $ 33,949 | $ 33,949 | $ 33,949 | $ 33,949 | $ 33,949 | 24,599 | 22,334 | 26,155 | 10,000 | 18,301 | 16,681 | 14,591 | 13,593 | 10,000 | 10,994 | 10,000 | 10,520 | 10,000 | |||
| Average Annual Return, Percent | 38.02% | 9.28% | 15.27% | 14.16% | 13.75% | 13% | ||||||||||||||||
| Bloomberg U S Aggregate Bond Index [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Aggregate Bond Index | |||||||||||||||||||||
| Account Value | $ 11,592 | $ 11,592 | $ 11,592 | $ 11,592 | $ 11,592 | $ 11,592 | 10,487 | 10,450 | 12,393 | 12,453 | 11,727 | 10,517 | 10,737 | 10,000 | 10,641 | 10,196 | 10,000 | |||||
| Average Annual Return, Percent | 10.55% | (0.23%) | 1.10% | 1.49% | ||||||||||||||||||
| S And P 500 Growth Index [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | S&P 500® Growth Index | |||||||||||||||||||||
| Account Value | $ 39,624 | 39,624 | $ 39,624 | $ 39,624 | 39,624 | $ 39,624 | 27,579 | 24,646 | 32,612 | 22,486 | 18,069 | 15,811 | 14,187 | 11,214 | 10,923 | 10,000 | ||||||
| Average Annual Return, Percent | 43.67% | 17.01% | 14.76% | |||||||||||||||||||
| Russell Midcap Value Index [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Russell Midcap® Value Index | |||||||||||||||||||||
| Account Value | $ 22,463.09214 | 22,463.09214 | $ 22,463.09214 | $ 22,463.09214 | 22,463.09214 | $ 22,463.09214 | 16,759.45782 | 17,378.53733 | 19,347.21848 | 13,019.7729 | 13,990.35025 | 12,709.55359 | 12,688.76221 | 10,000 | 10,834.21248 | 10,046.76037 | 10,000 | |||||
| Average Annual Return, Percent | 34.03% | 9.93% | 8.52% | 8.43% | ||||||||||||||||||
| Russell 3000 Value Index [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Russell 3000® Value Index | |||||||||||||||||||||
| Account Value | $ 23,181 | 23,181 | $ 23,181 | $ 23,181 | $ 23,181 | $ 23,181 | 17,693 | 17,778 | 19,167 | 13,221 | 14,371 | 12,988 | 12,636 | 10,000 | 10,681 | $ 10,000 | 10,024 | 10,000 | ||||
| Average Annual Return, Percent | 31.02% | 10.04% | 9.05% | 9.59% | 8.77% | |||||||||||||||||
| Russell 2000 Value Index [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Russell 2000® Value Index | |||||||||||||||||||||
| Account Value | $ 20,278.18724 | 20,278.18724 | $ 20,278.18724 | $ 20,278.18724 | $ 20,278.18724 | $ 20,278.18724 | 15,390.6639 | 17,087.38766 | 19,140.68522 | 11,649.95536 | 13,534.01133 | 13,111.88276 | 13,189.8491 | 10,000 | 10,568.0244 | 9,712.207176 | 10,000 | |||||
| Average Annual Return, Percent | 31.77% | 8.42% | 6.28% | 7.33% | ||||||||||||||||||
| Russell 2500 Value Index [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Russell 2500® Value Index | |||||||||||||||||||||
| Account Value | $ 21,324 | 21,324 | $ 21,324 | $ 21,324 | 21,324 | $ 21,324 | 16,101 | 16,938 | 18,958 | 11,988 | 13,609 | 12,827 | 12,793 | $ 10,000 | 10,663 | 9,894 | 10,000 | |||||
| Average Annual Return, Percent | 32.42% | 9.39% | 7.56% | 7.87% | ||||||||||||||||||
| Russell 2500 Growth Index [Member] | ||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||
| Line Graph and Table Measure Name | Russell 2500® Growth Index | |||||||||||||||||||||
| Account Value | $ 24,746 | $ 24,746 | $ 24,746 | $ 24,746 | $ 24,746 | $ 24,746 | $ 18,436 | $ 19,367 | $ 26,669 | $ 10,000 | $ 19,448 | $ 15,980 | $ 14,297 | $ 13,549 | $ 10,417 | $ 10,417 | $ 10,000 | |||||
| Average Annual Return, Percent | 34.21% | (1.99%) | 9.14% | 9.48% |
| Shareholder Report, Holdings (Details) | Oct. 31, 2024 |
| C000003009 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 67.30% |
| C000003009 [Member] | Apple Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.60% |
| C000003009 [Member] | NVIDIA Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.30% |
| C000003009 [Member] | Microsoft Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.20% |
| C000003009 [Member] | Adobe Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.90% |
| C000003009 [Member] | Alphabet Inc Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.30% |
| C000003009 [Member] | Amazon com Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.80% |
| C000003009 [Member] | Texas Instruments Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.80% |
| C000003009 [Member] | Meta Platforms Inc Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.40% |
| C000003009 [Member] | Workday Inc Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.40% |
| C000003009 [Member] | Mastercard Inc Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000003009 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 48.70% |
| C000003009 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.70% |
| C000003009 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.70% |
| C000003009 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.70% |
| C000003009 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.30% |
| C000003009 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.10% |
| C000003009 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| C000003009 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.30% |
| C000003009 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| C000003009 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000003009 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000003009 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| C000003010 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 67.30% |
| C000003010 [Member] | Apple Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.60% |
| C000003010 [Member] | NVIDIA Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.30% |
| C000003010 [Member] | Microsoft Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.20% |
| C000003010 [Member] | Adobe Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.90% |
| C000003010 [Member] | Alphabet Inc Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.30% |
| C000003010 [Member] | Amazon com Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.80% |
| C000003010 [Member] | Texas Instruments Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.80% |
| C000003010 [Member] | Meta Platforms Inc Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.40% |
| C000003010 [Member] | Workday Inc Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.40% |
| C000003010 [Member] | Mastercard Inc Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000003010 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 48.70% |
| C000003010 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.70% |
| C000003010 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.70% |
| C000003010 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.70% |
| C000003010 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.30% |
| C000003010 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.10% |
| C000003010 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| C000003010 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.30% |
| C000003010 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| C000003010 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000003010 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000003010 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| C000003029 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 39.30% |
| C000003029 [Member] | iShares Russell Mid Cap Value ETF [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.40% |
| C000003029 [Member] | Fairfax Financial Holdings Ltd Canada [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.60% |
| C000003029 [Member] | Willis Towers Watson PLC United Kingdom [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| C000003029 [Member] | Talen Energy Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.20% |
| C000003029 [Member] | Lululemon Athletica Inc Canada [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| C000003029 [Member] | Lithia Motors Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| C000003029 [Member] | Labcorp Holdings Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000003029 [Member] | BJ s Wholesale Club Holdings Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000003029 [Member] | The Kroger Co [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.20% |
| C000003029 [Member] | Expedia Group Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| C000003029 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 19.40% |
| C000003029 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.70% |
| C000003029 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.70% |
| C000003029 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.20% |
| C000003029 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.40% |
| C000003029 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.20% |
| C000003029 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000003029 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| C000003029 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.40% |
| C000003029 [Member] | Exchange Traded Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.40% |
| C000003029 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.10% |
| C000003029 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.80% |
| C000003029 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (1.00%) |
| C000003030 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 39.30% |
| C000003030 [Member] | iShares Russell Mid Cap Value ETF [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.40% |
| C000003030 [Member] | Fairfax Financial Holdings Ltd Canada [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.60% |
| C000003030 [Member] | Willis Towers Watson PLC United Kingdom [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| C000003030 [Member] | Talen Energy Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.20% |
| C000003030 [Member] | Lululemon Athletica Inc Canada [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| C000003030 [Member] | Lithia Motors Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| C000003030 [Member] | Labcorp Holdings Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000003030 [Member] | BJ s Wholesale Club Holdings Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000003030 [Member] | The Kroger Co [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.20% |
| C000003030 [Member] | Expedia Group Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| C000003030 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 19.40% |
| C000003030 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.70% |
| C000003030 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.70% |
| C000003030 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.20% |
| C000003030 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.40% |
| C000003030 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.20% |
| C000003030 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000003030 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| C000003030 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.40% |
| C000003030 [Member] | Exchange Traded Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.40% |
| C000003030 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.10% |
| C000003030 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.80% |
| C000003030 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (1.00%) |
| C000194566 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 39.30% |
| C000194566 [Member] | iShares Russell Mid Cap Value ETF [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.40% |
| C000194566 [Member] | Fairfax Financial Holdings Ltd Canada [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.60% |
| C000194566 [Member] | Willis Towers Watson PLC United Kingdom [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| C000194566 [Member] | Talen Energy Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.20% |
| C000194566 [Member] | Lululemon Athletica Inc Canada [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| C000194566 [Member] | Lithia Motors Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| C000194566 [Member] | Labcorp Holdings Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000194566 [Member] | BJ s Wholesale Club Holdings Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000194566 [Member] | The Kroger Co [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.20% |
| C000194566 [Member] | Expedia Group Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| C000194566 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 19.40% |
| C000194566 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.70% |
| C000194566 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.70% |
| C000194566 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.20% |
| C000194566 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.40% |
| C000194566 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.20% |
| C000194566 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000194566 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| C000194566 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.40% |
| C000194566 [Member] | Exchange Traded Funds [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.40% |
| C000194566 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.10% |
| C000194566 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.80% |
| C000194566 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (1.00%) |
| C000003037 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.70% |
| C000003037 [Member] | Oracle Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.60% |
| C000003037 [Member] | The Williams Cos Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.30% |
| C000003037 [Member] | Kinder Morgan Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| C000003037 [Member] | The Progressive Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000003037 [Member] | The PNC Financial Services Group Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.20% |
| C000003037 [Member] | Comcast Corp Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.20% |
| C000003037 [Member] | Unilever PLC Sponsored ADR United Kingdom [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.10% |
| C000003037 [Member] | Corning Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.10% |
| C000003037 [Member] | Cogent Communications Holdings Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.10% |
| C000003037 [Member] | American Tower Corp REIT [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| C000003037 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.30% |
| C000003037 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| C000003037 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| C000003037 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.20% |
| C000003037 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7% |
| C000003037 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.10% |
| C000003037 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.90% |
| C000003037 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.30% |
| C000003037 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000003037 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.50% |
| C000003037 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000003037 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (0.10%) |
| C000050291 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.70% |
| C000050291 [Member] | Oracle Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.60% |
| C000050291 [Member] | The Williams Cos Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.30% |
| C000050291 [Member] | Kinder Morgan Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| C000050291 [Member] | The Progressive Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000050291 [Member] | The PNC Financial Services Group Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.20% |
| C000050291 [Member] | Comcast Corp Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.20% |
| C000050291 [Member] | Unilever PLC Sponsored ADR United Kingdom [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.10% |
| C000050291 [Member] | Corning Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.10% |
| C000050291 [Member] | Cogent Communications Holdings Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.10% |
| C000050291 [Member] | American Tower Corp REIT [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| C000050291 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.30% |
| C000050291 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| C000050291 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| C000050291 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.20% |
| C000050291 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7% |
| C000050291 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.10% |
| C000050291 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.90% |
| C000050291 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.30% |
| C000050291 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000050291 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.50% |
| C000050291 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000050291 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (0.10%) |
| C000194567 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.70% |
| C000194567 [Member] | Oracle Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.60% |
| C000194567 [Member] | The Williams Cos Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.30% |
| C000194567 [Member] | Kinder Morgan Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| C000194567 [Member] | The Progressive Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000194567 [Member] | The PNC Financial Services Group Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.20% |
| C000194567 [Member] | Comcast Corp Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.20% |
| C000194567 [Member] | Unilever PLC Sponsored ADR United Kingdom [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.10% |
| C000194567 [Member] | Corning Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.10% |
| C000194567 [Member] | Cogent Communications Holdings Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.10% |
| C000194567 [Member] | American Tower Corp REIT [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| C000194567 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.30% |
| C000194567 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| C000194567 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| C000194567 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.20% |
| C000194567 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7% |
| C000194567 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.10% |
| C000194567 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.90% |
| C000194567 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.30% |
| C000194567 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000194567 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.50% |
| C000194567 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000194567 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (0.10%) |
| C000003038 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 29.60% |
| C000003038 [Member] | Talen Energy Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.30% |
| C000003038 [Member] | White Mountains Insurance Group Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.10% |
| C000003038 [Member] | McGrath RentCorp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000003038 [Member] | Murphy USA Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3% |
| C000003038 [Member] | UniFirst Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.90% |
| C000003038 [Member] | Summit Materials Inc Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.90% |
| C000003038 [Member] | Axis Capital Holdings Ltd Bermuda [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| C000003038 [Member] | CoreCivic Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000003038 [Member] | The GEO Group Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000003038 [Member] | Genworth Financial Inc Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| C000003038 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.30% |
| C000003038 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.90% |
| C000003038 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| C000003038 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| C000003038 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.90% |
| C000003038 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 18.20% |
| C000003038 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.10% |
| C000003038 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000003038 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.10% |
| C000003038 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.10% |
| C000003038 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.50% |
| C000003038 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.30% |
| C000003038 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (0.10%) |
| C000040086 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 29.60% |
| C000040086 [Member] | Talen Energy Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.30% |
| C000040086 [Member] | White Mountains Insurance Group Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.10% |
| C000040086 [Member] | McGrath RentCorp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000040086 [Member] | Murphy USA Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3% |
| C000040086 [Member] | UniFirst Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.90% |
| C000040086 [Member] | Summit Materials Inc Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.90% |
| C000040086 [Member] | Axis Capital Holdings Ltd Bermuda [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| C000040086 [Member] | CoreCivic Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000040086 [Member] | The GEO Group Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000040086 [Member] | Genworth Financial Inc Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| C000040086 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.30% |
| C000040086 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.90% |
| C000040086 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| C000040086 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| C000040086 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.90% |
| C000040086 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 18.20% |
| C000040086 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.10% |
| C000040086 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000040086 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.10% |
| C000040086 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.10% |
| C000040086 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.50% |
| C000040086 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.30% |
| C000040086 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (0.10%) |
| C000194568 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 29.60% |
| C000194568 [Member] | Talen Energy Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.30% |
| C000194568 [Member] | White Mountains Insurance Group Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.10% |
| C000194568 [Member] | McGrath RentCorp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000194568 [Member] | Murphy USA Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3% |
| C000194568 [Member] | UniFirst Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.90% |
| C000194568 [Member] | Summit Materials Inc Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.90% |
| C000194568 [Member] | Axis Capital Holdings Ltd Bermuda [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| C000194568 [Member] | CoreCivic Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000194568 [Member] | The GEO Group Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000194568 [Member] | Genworth Financial Inc Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| C000194568 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.30% |
| C000194568 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.90% |
| C000194568 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| C000194568 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| C000194568 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.90% |
| C000194568 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 18.20% |
| C000194568 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.10% |
| C000194568 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000194568 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.10% |
| C000194568 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.10% |
| C000194568 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.50% |
| C000194568 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.30% |
| C000194568 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (0.10%) |
| C000046749 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 29.50% |
| C000046749 [Member] | Talen Energy Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3% |
| C000046749 [Member] | Lithia Motors Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000046749 [Member] | BJ s Wholesale Club Holdings Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| C000046749 [Member] | White Mountains Insurance Group Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000046749 [Member] | McGrath RentCorp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.20% |
| C000046749 [Member] | Murphy USA Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.20% |
| C000046749 [Member] | UniFirst Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000046749 [Member] | TD SYNNEX Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000046749 [Member] | WEX Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000046749 [Member] | LKQ Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| C000046749 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.50% |
| C000046749 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14.80% |
| C000046749 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000046749 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.20% |
| C000046749 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 26.30% |
| C000046749 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.80% |
| C000046749 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.70% |
| C000046749 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.70% |
| C000046749 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000046749 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.80% |
| C000046749 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 87.30% |
| C000046749 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 6.10% |
| C000046749 [Member] | BERMUDA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.60% |
| C000046749 [Member] | PUERTO RICO | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.10% |
| C000046749 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.90% |
| C000046749 [Member] | IRELAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.80% |
| C000046749 [Member] | ISRAEL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.20% |
| C000046749 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.70% |
| C000046749 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (0.90%) |
| C000050292 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 29.50% |
| C000050292 [Member] | Talen Energy Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3% |
| C000050292 [Member] | Lithia Motors Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000050292 [Member] | BJ s Wholesale Club Holdings Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| C000050292 [Member] | White Mountains Insurance Group Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000050292 [Member] | McGrath RentCorp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.20% |
| C000050292 [Member] | Murphy USA Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.20% |
| C000050292 [Member] | UniFirst Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000050292 [Member] | TD SYNNEX Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000050292 [Member] | WEX Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000050292 [Member] | LKQ Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| C000050292 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.50% |
| C000050292 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14.80% |
| C000050292 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000050292 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.20% |
| C000050292 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 26.30% |
| C000050292 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.80% |
| C000050292 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.70% |
| C000050292 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.70% |
| C000050292 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000050292 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.80% |
| C000050292 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 87.30% |
| C000050292 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 6.10% |
| C000050292 [Member] | BERMUDA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.60% |
| C000050292 [Member] | PUERTO RICO | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.10% |
| C000050292 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.90% |
| C000050292 [Member] | IRELAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.80% |
| C000050292 [Member] | ISRAEL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.20% |
| C000050292 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.70% |
| C000050292 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (0.90%) |
| C000194569 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 29.50% |
| C000194569 [Member] | Talen Energy Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3% |
| C000194569 [Member] | Lithia Motors Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000194569 [Member] | BJ s Wholesale Club Holdings Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| C000194569 [Member] | White Mountains Insurance Group Ltd [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000194569 [Member] | McGrath RentCorp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.20% |
| C000194569 [Member] | Murphy USA Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.20% |
| C000194569 [Member] | UniFirst Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000194569 [Member] | TD SYNNEX Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000194569 [Member] | WEX Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000194569 [Member] | LKQ Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| C000194569 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.50% |
| C000194569 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14.80% |
| C000194569 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000194569 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.20% |
| C000194569 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 26.30% |
| C000194569 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.80% |
| C000194569 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.70% |
| C000194569 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.70% |
| C000194569 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000194569 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.80% |
| C000194569 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 87.30% |
| C000194569 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 6.10% |
| C000194569 [Member] | BERMUDA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.60% |
| C000194569 [Member] | PUERTO RICO | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.10% |
| C000194569 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.90% |
| C000194569 [Member] | IRELAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.80% |
| C000194569 [Member] | ISRAEL | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.20% |
| C000194569 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.70% |
| C000194569 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (0.90%) |
| C000092914 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.20% |
| C000092914 [Member] | CyberArk Software Ltd Israel [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000092914 [Member] | Texas Roadhouse Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| C000092914 [Member] | Tyler Technologies Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.10% |
| C000092914 [Member] | Houlihan Lokey Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.10% |
| C000092914 [Member] | ITT Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000092914 [Member] | CACI International Inc Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000092914 [Member] | Burlington Stores Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000092914 [Member] | Entegris Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000092914 [Member] | Globant SA Uruguay [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000092914 [Member] | Manhattan Associates Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.80% |
| C000092914 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.20% |
| C000092914 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.80% |
| C000092914 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23% |
| C000092914 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22% |
| C000092914 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.10% |
| C000092914 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.40% |
| C000092914 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| C000092914 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.80% |
| C000092914 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2% |
| C000092914 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.90% |
| C000092914 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (0.20%) |
| C000101741 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.20% |
| C000101741 [Member] | CyberArk Software Ltd Israel [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000101741 [Member] | Texas Roadhouse Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| C000101741 [Member] | Tyler Technologies Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.10% |
| C000101741 [Member] | Houlihan Lokey Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.10% |
| C000101741 [Member] | ITT Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000101741 [Member] | CACI International Inc Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000101741 [Member] | Burlington Stores Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000101741 [Member] | Entegris Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000101741 [Member] | Globant SA Uruguay [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000101741 [Member] | Manhattan Associates Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.80% |
| C000101741 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.20% |
| C000101741 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.80% |
| C000101741 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23% |
| C000101741 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22% |
| C000101741 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.10% |
| C000101741 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.40% |
| C000101741 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| C000101741 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.80% |
| C000101741 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2% |
| C000101741 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.90% |
| C000101741 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (0.20%) |
| C000230346 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.20% |
| C000230346 [Member] | CyberArk Software Ltd Israel [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000230346 [Member] | Texas Roadhouse Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| C000230346 [Member] | Tyler Technologies Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.10% |
| C000230346 [Member] | Houlihan Lokey Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.10% |
| C000230346 [Member] | ITT Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000230346 [Member] | CACI International Inc Class A [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000230346 [Member] | Burlington Stores Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000230346 [Member] | Entegris Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000230346 [Member] | Globant SA Uruguay [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000230346 [Member] | Manhattan Associates Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.80% |
| C000230346 [Member] | Information Technology Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.20% |
| C000230346 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.80% |
| C000230346 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23% |
| C000230346 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22% |
| C000230346 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.10% |
| C000230346 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.40% |
| C000230346 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| C000230346 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.80% |
| C000230346 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2% |
| C000230346 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.90% |
| C000230346 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (0.20%) |
| C000102286 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37% |
| C000102286 [Member] | U S Treasury Notes 4 500 11 15 33 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.40% |
| C000102286 [Member] | U S Treasury Bonds 4 250 02 15 54 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.40% |
| C000102286 [Member] | U S Treasury Notes 3 500 09 30 29 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000102286 [Member] | FNMA 2 140 10 01 29 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000102286 [Member] | U S Treasury Bonds 3 000 08 15 52 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000102286 [Member] | U S Treasury Bonds 1 875 02 15 41 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000102286 [Member] | Bank of America Corp 4 376 04 27 28 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000102286 [Member] | FNMA 2 260 01 01 30 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000102286 [Member] | U S Treasury Notes 3 500 02 15 33 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| C000102286 [Member] | FNMA 3 000 06 01 52 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000102286 [Member] | Aaa AAA [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000102286 [Member] | Aa AA [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 6.40% |
| C000102286 [Member] | A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 9% |
| C000102286 [Member] | Baa BBB [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 22.20% |
| C000102286 [Member] | Ba BB [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000102286 [Member] | US Government Corporations and Agencies Securities Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 58.70% |
| C000102286 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.40% |
| C000102286 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (2.70%) |
| C000102286 [Member] | US Government Corporations and Agencies Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 56.50% |
| C000102286 [Member] | Corporate Bonds And Notes [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.10% |
| C000102286 [Member] | Collateralized Mortgage Obligations [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| C000102286 [Member] | Municipal Bonds [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| C000102287 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37% |
| C000102287 [Member] | U S Treasury Notes 4 500 11 15 33 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.40% |
| C000102287 [Member] | U S Treasury Bonds 4 250 02 15 54 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.40% |
| C000102287 [Member] | U S Treasury Notes 3 500 09 30 29 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000102287 [Member] | FNMA 2 140 10 01 29 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000102287 [Member] | U S Treasury Bonds 3 000 08 15 52 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000102287 [Member] | U S Treasury Bonds 1 875 02 15 41 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000102287 [Member] | Bank of America Corp 4 376 04 27 28 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000102287 [Member] | FNMA 2 260 01 01 30 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000102287 [Member] | U S Treasury Notes 3 500 02 15 33 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| C000102287 [Member] | FNMA 3 000 06 01 52 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000102287 [Member] | Aaa AAA [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000102287 [Member] | Aa AA [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 6.40% |
| C000102287 [Member] | A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 9% |
| C000102287 [Member] | Baa BBB [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 22.20% |
| C000102287 [Member] | Ba BB [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000102287 [Member] | US Government Corporations and Agencies Securities Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 58.70% |
| C000102287 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.40% |
| C000102287 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (2.70%) |
| C000102287 [Member] | US Government Corporations and Agencies Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 56.50% |
| C000102287 [Member] | Corporate Bonds And Notes [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.10% |
| C000102287 [Member] | Collateralized Mortgage Obligations [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| C000102287 [Member] | Municipal Bonds [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| C000194571 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37% |
| C000194571 [Member] | U S Treasury Notes 4 500 11 15 33 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.40% |
| C000194571 [Member] | U S Treasury Bonds 4 250 02 15 54 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.40% |
| C000194571 [Member] | U S Treasury Notes 3 500 09 30 29 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000194571 [Member] | FNMA 2 140 10 01 29 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000194571 [Member] | U S Treasury Bonds 3 000 08 15 52 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000194571 [Member] | U S Treasury Bonds 1 875 02 15 41 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000194571 [Member] | Bank of America Corp 4 376 04 27 28 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000194571 [Member] | FNMA 2 260 01 01 30 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000194571 [Member] | U S Treasury Notes 3 500 02 15 33 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| C000194571 [Member] | FNMA 3 000 06 01 52 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000194571 [Member] | Aaa AAA [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000194571 [Member] | Aa AA [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 6.40% |
| C000194571 [Member] | A [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 9% |
| C000194571 [Member] | Baa BBB [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 22.20% |
| C000194571 [Member] | Ba BB [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000194571 [Member] | US Government Corporations and Agencies Securities Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 58.70% |
| C000194571 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.40% |
| C000194571 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (2.70%) |
| C000194571 [Member] | US Government Corporations and Agencies Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 56.50% |
| C000194571 [Member] | Corporate Bonds And Notes [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.10% |
| C000194571 [Member] | Collateralized Mortgage Obligations [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| C000194571 [Member] | Municipal Bonds [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| C000161968 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.80% |
| C000161968 [Member] | Fairfax Financial Holdings Ltd Canada [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| C000161968 [Member] | Talen Energy Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000161968 [Member] | BJ s Wholesale Club Holdings Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5% |
| C000161968 [Member] | The Kroger Co [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| C000161968 [Member] | Berkshire Hathaway Inc Class B [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6% |
| C000161968 [Member] | CRH PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| C000161968 [Member] | Papa John s International Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| C000161968 [Member] | Mid America Apartment Communities Inc REIT [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| C000161968 [Member] | Northwestern Energy Group Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.40% |
| C000161968 [Member] | SS And C Technologies Holdings Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.40% |
| C000161968 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 19.20% |
| C000161968 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.30% |
| C000161968 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| C000161968 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13% |
| C000161968 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.30% |
| C000161968 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| C000161968 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| C000161968 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.60% |
| C000161968 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| C000161968 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7% |
| C000161968 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| C000161968 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (0.30%) |
| C000161967 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.80% |
| C000161967 [Member] | Fairfax Financial Holdings Ltd Canada [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| C000161967 [Member] | Talen Energy Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000161967 [Member] | BJ s Wholesale Club Holdings Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5% |
| C000161967 [Member] | The Kroger Co [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| C000161967 [Member] | Berkshire Hathaway Inc Class B [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6% |
| C000161967 [Member] | CRH PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| C000161967 [Member] | Papa John s International Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| C000161967 [Member] | Mid America Apartment Communities Inc REIT [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| C000161967 [Member] | Northwestern Energy Group Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.40% |
| C000161967 [Member] | SS And C Technologies Holdings Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.40% |
| C000161967 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 19.20% |
| C000161967 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.30% |
| C000161967 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| C000161967 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13% |
| C000161967 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.30% |
| C000161967 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| C000161967 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| C000161967 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.60% |
| C000161967 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| C000161967 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7% |
| C000161967 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| C000161967 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (0.30%) |
| C000194575 [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.80% |
| C000194575 [Member] | Fairfax Financial Holdings Ltd Canada [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| C000194575 [Member] | Talen Energy Corp [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000194575 [Member] | BJ s Wholesale Club Holdings Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5% |
| C000194575 [Member] | The Kroger Co [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| C000194575 [Member] | Berkshire Hathaway Inc Class B [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6% |
| C000194575 [Member] | CRH PLC [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| C000194575 [Member] | Papa John s International Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| C000194575 [Member] | Mid America Apartment Communities Inc REIT [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| C000194575 [Member] | Northwestern Energy Group Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.40% |
| C000194575 [Member] | SS And C Technologies Holdings Inc [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.40% |
| C000194575 [Member] | Consumer Discretionary Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 19.20% |
| C000194575 [Member] | Communications Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.30% |
| C000194575 [Member] | Healthcare Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| C000194575 [Member] | Industrial Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13% |
| C000194575 [Member] | Financial Services Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.30% |
| C000194575 [Member] | Consumer Staples Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| C000194575 [Member] | Energy Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| C000194575 [Member] | Materials Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.60% |
| C000194575 [Member] | Real Estate Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| C000194575 [Member] | Utilities Sector [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7% |
| C000194575 [Member] | Short-Term Investments [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| C000194575 [Member] | Other Assets less Liabilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (0.30%) |
