| Cover | May 14, 2024 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | May 14, 2024 |
| Current Fiscal Year End Date | --10-31 |
| Entity File Number | 811-21484 |
| Entity Registrant Name | Calamos Strategic Total Return Fund |
| Entity Central Index Key | 0001275214 |
| Entity Tax Identification Number | 04-3785941 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 2020 Calamos Court |
| Entity Address, City or Town | Naperville |
| Entity Address, State or Province | IL |
| Entity Address, Postal Zip Code | 60563 |
| City Area Code | 630 |
| Local Phone Number | 245-7200 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Shares |
| Trading Symbol | CSQ |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
