| Shareholder Report | 6 Months Ended | 120 Months Ended |
| Oct. 31, 2024 USD ($) Holding | Oct. 31, 2024 USD ($) Holding |
| Shareholder Report [Line Items] | | |
| Document Type | N-CSRS | |
| Amendment Flag | false | |
| Registrant Name | Capitol Series Trust | |
| Entity Central Index Key | 0001587551 | |
| Entity Investment Company Type | N-1A | |
| Document Period End Date | Oct. 31, 2024 | |
| C000167184 | | |
| Shareholder Report [Line Items] | | |
| Fund Name | Canterbury Portfolio Thermostat Fund | |
| Class Name | Institutional Shares | |
| Trading Symbol | CAPTX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about Canterbury Portfolio Thermostat Fund for the period of May 1, 2024 to December 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | Semi-Annual Shareholder Report | |
| Additional Information [Text Block] | You can find additional information about the Fund at https://www.canterburygroup.com/mutualfund | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the reporting period. | |
| Additional Information Phone Number | (844) 838-2121 | |
| Additional Information Website | https://www.canterburygroup.com/mutualfund | |
| Expenses [Text Block] | What were the Fund’s costs for the last six months? (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 $183 3.53% | |
| Expenses Paid, Amount | $ 183 | |
| Expense Ratio, Percent | 3.53% | |
| Performance Past Does Not Indicate Future [Text] | The Fund's past performance is not a good predictor of how the Fund will perform in the future. | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns 1 Year 5 Years Since Inception (August 2, 2016) Canterbury Portfolio Thermostat - Institutional Shares 13.21% 2.28% 3.41% MSCI World Index (Gross) 34.29% 12.57% 12.10% 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. | |
| Performance Inception Date | | Aug. 02, 2016 |
| 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. | |
| Material Change Date | Oct. 31, 2024 | |
| AssetsNet | $ 8,101,933 | $ 8,101,933 |
| Holdings Count | Holding | 18 | 18 |
| Advisory Fees Paid, Amount | $ 9,634 | |
| InvestmentCompanyPortfolioTurnover | 80% | |
| Additional Fund Statistics [Text Block] | Fund Statistics Net Assets $8,101,933 Number of Portfolio Holdings 18 Advisory Fee #ERROR:A result could not be returned because the conditional could not be evaluated to a True/False value ((history)) $9,634 Portfolio Turnover 80% | |
| Holdings [Text Block] | Portfolio Composition (% of net assets) Value Value Liabilities in Excess of Other Assets -0.1% Communications 4.0% Technology 4.3% Industrials 4.3% Financials 4.9% Utilities 5.5% Money Market Funds 8.1% Materials 8.8% Consumer Staples 9.8% Exchange-Traded Funds 50.4% | |
