Cover |
12 Months Ended |
|---|---|
Dec. 31, 2025 | |
| Document Information [Line Items] | |
| Entity Registrant Name | CASS INFORMATION SYSTEMS, INC. |
| Document Type | 11-K |
| Amendment Flag | false |
| Entity Central Index Key | 0000708781 |
| EBP 002 | |
| Document Information [Line Items] | |
| Entity Registrant Name | CASS INFORMATION SYSTEMS, INC. |
| Document Type | 11-K |
| Amendment Flag | false |
| Entity Central Index Key | 0000708781 |