| Document and Entity Information | Mar. 27, 2024 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Mar. 27, 2024 |
| Entity Registrant Name | DWS STRATEGIC MUNICIPAL INCOME TRUST |
| Entity Incorporation State Country Code | MA |
| Entity File Number | 811-05767 |
| Entity Tax Identification Number | 36-3629052 |
| Entity Address Address Line 1 | 875 Third Avenue |
| Entity Address City Or Town | New York |
| Entity Address State Or Province | NY |
| Entity Address Postal Zip Code | 10022 |
| City Area Code | 212 |
| Local Phone Number | 454-4500 |
| Written Communications | false |
| Entity Emerging Growth Company | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Amendment Flag | false |
| Entity Central Index Key | 0000846596 |
