| Shareholder Report | 12 Months Ended |
| Dec. 31, 2024 USD ($) Holding |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | Federated Hermes Adviser Series |
| Entity Central Index Key | 0001707560 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Dec. 31, 2024 |
| C000228384 | |
| Shareholder Report [Line Items] | |
| Fund Name | Federated Hermes MDT Market Neutral Fund |
| Class Name | Class A Shares |
| Trading Symbol | QAMNX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the Federated Hermes MDT Market Neutral Fund (the "Fund") for the period of January 1, 2024 to December 31, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information Phone Number | 1-800-341-7400 |
| Additional Information Website | FederatedHermes.com/us/FundInformation |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A Shares $224 2.06% |
| Expenses Paid, Amount | $ 224 |
| Expense Ratio, Percent | 2.06% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance The following discussion compares the performance of the Fund to the ICE 3 Month US Treasury Bill Index to show how the Fund’s performance compares to the returns of similar investments for the reporting period. See the Average Annual Total Returns table below for the returns of the Fund and related indexes, including the Russell 3000 Index, which represents approximately 98% of investable U.S. equities by market capitalization. The Fund seeks to provide long-term capital appreciation while limiting exposure to general stock market risk. Top Contributors to Performance An underweight position in and solid stock selection among companies with significant financing requirements and negative analyst conviction contributed positively to Fund relative performance. By sector, stock selection in Information Technology, Industrials and Utilities aided performance. Top individual Fund holdings that contributed positively to performance included long positions in AppLovin Corporation (Class A Shares) and Vistra Corp., and a short position in Super Micro Computer, Inc. Top Detractors from Performance Poor stock selection among companies with flat or improving earnings to price ratios and negative analyst conviction detracted from Fund relative performance. By sector, stock selection in Materials detracted from performance. Top individual Fund holdings that detracted from performance were short positions in Broadcom Inc., Upstart Holdings, Inc. and Tesla, Inc. |
| Performance Past Does Not Indicate Future [Text] | Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future. |
| Line Graph [Table Text Block] | Class A Shares with sales load Russell 3000 ® ICE 3M US T-Bill Index Morningstar Equity Market Neutral Funds Average 12/31/2014 $9,449 $10,000 $10,000 $10,000 12/31/2015 $9,457 $10,048 $10,005 $10,176 12/31/2016 $9,770 $11,327 $10,038 $10,299 12/31/2017 $10,518 $13,721 $10,124 $10,650 12/31/2018 $9,917 $13,002 $10,314 $10,626 12/31/2019 $11,033 $17,035 $10,549 $10,630 12/31/2020 $10,591 $20,593 $10,619 $10,078 12/31/2021 $13,051 $25,877 $10,625 $10,799 12/31/2022 $14,250 $20,907 $10,779 $11,452 12/31/2023 $14,920 $26,334 $11,320 $12,058 12/31/2024 $17,505 $32,604 $11,914 $13,139 |
| Average Annual Return [Table Text Block] | Fund/Index 1 Year 5 Years 10 Years Class A Shares with sales load 10.89% 8.44% 5.76% Class A Shares without sales load 17.32% 9.67% 6.36% Russell 3000 ® Index Footnote Reference * 23.81% 13.86% 12.54% ICE 3M US T-Bill Index 5.25% 2.46% 1.77% Morningstar Equity Market Neutral Funds Average 9.12% 4.23% 2.72% |
| 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. |
| Performance Table Market Index Changed [Text Block] | The Fund has designated the Russell 3000 ® |
| AssetsNet | $ 942,584,614 |
| Holdings Count | Holding | 409 |
| Advisory Fees Paid, Amount | $ 4,276,825 |
| InvestmentCompanyPortfolioTurnover | 58% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics Net Assets $942,584,614 Number of Investments 409 Portfolio Turnover 58% Total Advisory Fees Paid $4,276,825 |
| Holdings [Text Block] | Top Security Types (% of Net Assets) Value Value Securities Sold Short (73.9%) Cash Equivalents 12.5% Collateral on Deposit for Securities Sold Short 76.4% Common Stocks 80.5% Top Sectors (% of Total Securities Sold Short) Value Value Utilities 1.9% Materials 3.4% Real Estate 3.8% Communication Services 4.1% Energy 4.2% Consumer Staples 7.7% Consumer Discretionary 10.4% Financials 12.9% Health Care 12.9% Industrials 13.1% Information Technology 25.6% |
| Material Fund Change [Text Block] | |
| C000228383 | |
| Shareholder Report [Line Items] | |
| Fund Name | Federated Hermes MDT Market Neutral Fund |
| Class Name | Institutional Shares |
| Trading Symbol | QQMNX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the Federated Hermes MDT Market Neutral Fund (the "Fund") for the period of January 1, 2024 to December 31, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information Phone Number | 1-800-341-7400 |
| Additional Information Website | FederatedHermes.com/us/FundInformation |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Institutional Shares $201 1.85% |
| Expenses Paid, Amount | $ 201 |
| Expense Ratio, Percent | 1.85% |
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance The following discussion compares the performance of the Fund to the ICE 3 Month US Treasury Bill Index to show how the Fund’s performance compares to the returns of similar investments for the reporting period. See the Average Annual Total Returns table below for the returns of the Fund and related indexes, including the Russell 3000 Index, which represents approximately 98% of investable U.S. equities by market capitalization. The Fund seeks to provide long-term capital appreciation while limiting exposure to general stock market risk. Top Contributors to Performance An underweight position in and solid stock selection among companies with significant financing requirements and negative analyst conviction contributed positively to Fund relative performance. By sector, stock selection in Information Technology, Industrials and Utilities aided performance. Top individual Fund holdings that contributed positively to performance included long positions in AppLovin Corporation (Class A Shares) and Vistra Corp., and a short position in Super Micro Computer, Inc. Top Detractors from Performance Poor stock selection among companies with flat or improving earnings to price ratios and negative analyst conviction detracted from Fund relative performance. By sector, stock selection in Materials detracted from performance. Top individual Fund holdings that detracted from performance were short positions in Broadcom Inc., Upstart Holdings, Inc. and Tesla, Inc. |
| Performance Past Does Not Indicate Future [Text] | Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future. |
| Line Graph [Table Text Block] | Institutional Shares Russell 3000 ® ICE 3M US T-Bill Index Morningstar Equity Market Neutral Funds Average 12/31/2014 $10,000 $10,000 $10,000 $10,000 12/31/2015 $10,031 $10,048 $10,005 $10,176 12/31/2016 $10,385 $11,327 $10,038 $10,299 12/31/2017 $11,181 $13,721 $10,124 $10,650 12/31/2018 $10,553 $13,002 $10,314 $10,626 12/31/2019 $11,764 $17,035 $10,549 $10,630 12/31/2020 $11,324 $20,593 $10,619 $10,078 12/31/2021 $13,925 $25,877 $10,625 $10,799 12/31/2022 $15,242 $20,907 $10,779 $11,452 12/31/2023 $15,999 $26,334 $11,320 $12,058 12/31/2024 $18,812 $32,604 $11,914 $13,139 |
| Average Annual Return [Table Text Block] | Fund/Index 1 Year 5 Years 10 Years Institutional Shares 17.58% 9.84% 6.52% Russell 3000 ® Index Footnote Reference * 23.81% 13.86% 12.54% ICE 3M US T-Bill Index 5.25% 2.46% 1.77% Morningstar Equity Market Neutral Funds Average 9.12% 4.23% 2.72% |
| 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. |
| Performance Table Market Index Changed [Text Block] | The Fund has designated the Russell 3000 ® |
| AssetsNet | $ 942,584,614 |
| Holdings Count | Holding | 409 |
| Advisory Fees Paid, Amount | $ 4,276,825 |
| InvestmentCompanyPortfolioTurnover | 58% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics Net Assets $942,584,614 Number of Investments 409 Portfolio Turnover 58% Total Advisory Fees Paid $4,276,825 |
| Holdings [Text Block] | Top Security Types (% of Net Assets) Value Value Securities Sold Short (73.9%) Cash Equivalents 12.5% Collateral on Deposit for Securities Sold Short 76.4% Common Stocks 80.5% Top Sectors (% of Total Securities Sold Short) Value Value Utilities 1.9% Materials 3.4% Real Estate 3.8% Communication Services 4.1% Energy 4.2% Consumer Staples 7.7% Consumer Discretionary 10.4% Financials 12.9% Health Care 12.9% Industrials 13.1% Information Technology 25.6% |
| Material Fund Change [Text Block] | |
