| Shareholder Report | 12 Months Ended | ||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Aug. 31, 2025  USD ($)  Holding | |||||||||||||||||||||||||||
| Shareholder Report [Line Items] | |||||||||||||||||||||||||||
| Document Type | N-CSR/A | ||||||||||||||||||||||||||
| Amendment Flag | false | ||||||||||||||||||||||||||
| Registrant Name | Federated Hermes Adviser Series | ||||||||||||||||||||||||||
| Entity Central Index Key | 0001707560 | ||||||||||||||||||||||||||
| Entity Investment Company Type | N-1A | ||||||||||||||||||||||||||
| Document Period End Date | Aug. 31, 2025 | ||||||||||||||||||||||||||
| C000214506 [Member] | |||||||||||||||||||||||||||
| Shareholder Report [Line Items] | |||||||||||||||||||||||||||
| Fund Name | Federated Hermes SDG Engagement High Yield Credit Fund | ||||||||||||||||||||||||||
| Class Name | Institutional Shares | ||||||||||||||||||||||||||
| Trading Symbol | FHHIX | ||||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the Federated Hermes SDG Engagement High Yield Credit Fund (the “Fund”) for the period of September 1, 2024 to August 31, 2025. | ||||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | annual shareholder report | ||||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the Fund at FederatedHermes.com/us/FundInformation. You can also request this information by contacting us at 1‑800‑341‑7400, Option 4, or your financial advisor. | ||||||||||||||||||||||||||
| 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) 
 | ||||||||||||||||||||||||||
| Expenses Paid, Amount | $ 64 | ||||||||||||||||||||||||||
| Expense Ratio, Percent | 0.62% | ||||||||||||||||||||||||||
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance The following discussion compares the performance of the Fund to the ICE BofA Global High Yield Constrained USD Hedged 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 Bloomberg Global Aggregate Index, which represents the overall global investment-grade debt market. The Fund seeks to provide current income and long-term capital appreciation alongside positive societal impact. Top Contributors to Performance 
 Top Detractors from Performance 
 | ||||||||||||||||||||||||||
| 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] | Fund Performance Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. Cumulative Performance: September 26, 2019 through August 31, 2025 Initial Investment of $10,000   | ||||||||||||||||||||||||||
| Average Annual Return [Table Text Block] | 
 
 | ||||||||||||||||||||||||||
| Performance Inception Date | Sep. 26, 2019 | ||||||||||||||||||||||||||
| 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] | Visit FederatedHermes.com/us/FundInformation and click on the link to your fund and share class for more recent performance information. | ||||||||||||||||||||||||||
| Net Assets | $ 140,884,008 | ||||||||||||||||||||||||||
| Holdings Count | Holding | 249 | ||||||||||||||||||||||||||
| Advisory Fees Paid, Amount | $ 181,970 | ||||||||||||||||||||||||||
| Investment Company Portfolio Turnover | 29.00% | ||||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key Fund Statistics 
 | ||||||||||||||||||||||||||
| Holdings [Text Block] | Fund Holdings Top Sectors  (% of Net Assets)   | ||||||||||||||||||||||||||
| C000214509 [Member] | |||||||||||||||||||||||||||
| Shareholder Report [Line Items] | |||||||||||||||||||||||||||
| Fund Name | Federated Hermes SDG Engagement High Yield Credit Fund | ||||||||||||||||||||||||||
| Class Name | Class R6 Shares | ||||||||||||||||||||||||||
| Trading Symbol | FHHRX | ||||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the Federated Hermes SDG Engagement High Yield Credit Fund (the “Fund”) for the period of September 1, 2024 to August 31, 2025. | ||||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | annual shareholder report | ||||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the Fund at FederatedHermes.com/us/FundInformation. You can also request this information by contacting us at 1‑800‑341‑7400, Option 4, or your financial advisor. | ||||||||||||||||||||||||||
| 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) 
 | ||||||||||||||||||||||||||
| Expenses Paid, Amount | $ 59 | ||||||||||||||||||||||||||
| Expense Ratio, Percent | 0.57% | ||||||||||||||||||||||||||
| Factors Affecting Performance [Text Block] | Management's Discussion of Fund Performance The following discussion compares the performance of the Fund to the ICE BofA Global High Yield Constrained USD Hedged 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 Bloomberg Global Aggregate Index, which represents the overall global investment-grade debt market. The Fund seeks to provide current income and long-term capital appreciation alongside positive societal impact. Top Contributors to Performance 
 Top Detractors from Performance 
 | ||||||||||||||||||||||||||
| 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] | Fund Performance Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. Cumulative Performance: September 26, 2019 through August 31, 2025 Initial Investment of $10,000   | ||||||||||||||||||||||||||
| Average Annual Return [Table Text Block] | 
 
 | ||||||||||||||||||||||||||
| Performance Inception Date | Jun. 11, 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] | Visit FederatedHermes.com/us/FundInformation and click on the link to your fund and share class for more recent performance information. | ||||||||||||||||||||||||||
| Net Assets | $ 140,884,008 | ||||||||||||||||||||||||||
| Holdings Count | Holding | 249 | ||||||||||||||||||||||||||
| Advisory Fees Paid, Amount | $ 181,970 | ||||||||||||||||||||||||||
| Investment Company Portfolio Turnover | 29.00% | ||||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key Fund Statistics 
 | ||||||||||||||||||||||||||
| Holdings [Text Block] | Fund Holdings Top Sectors  (% of Net Assets)   |