v3.25.4
Capital Requirements and Regulatory Restrictions (Tables)
 12 Months Ended
Dec. 31, 2025
Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract]  
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations
The Company’s and the Bank’s actual and required capital amounts and ratios are as follows:
ActualCapital
Requirements		Requirement to be
Well-Capitalized
(In thousands)AmountRatioAmountRatioAmountRatio
At December 31, 2025
Total capital (to risk-weighted assets)
Cass Information Systems, Inc. $262,792 15.95 %$131,837 8.00 %$        N/AN/A %
Cass Commercial Bank 217,409 19.61 88,677 8.00 110,847 10.00 
Common Equity Tier I Capital (to risk-weighted assets)
Cass Information Systems, Inc. 248,776 15.10 74,158 4.50 N/AN/A
Cass Commercial Bank 203,943 18.40 49,881 4.50 72,050 6.50 
Tier I capital (to risk-weighted assets)
Cass Information Systems, Inc. 248,776 15.10 98,878 6.00 N/AN/A
Cass Commercial Bank 203,943 18.40 66,508 6.00 88,677 8.00 
Tier I capital (to average assets)
Cass Information Systems, Inc. 248,776 9.91 100,367 4.00 N/AN/A
Cass Commercial Bank 203,943 14.48 56,357 4.00 70,446 5.00 
At December 31, 2024
Total capital (to risk-weighted assets)
Cass Information Systems, Inc. $261,021 14.61 %$142,969 8.00 %$        N/AN/A %
Cass Commercial Bank 207,519 17.68 93,911 8.00 117,389 10.00 
Common Equity Tier I Capital (to risk-weighted assets)
Cass Information Systems, Inc. 247,354 13.84 80,420 4.50 N/AN/A
Cass Commercial Bank 194,446 16.56 52,825 4.50 76,303 6.50 
Tier I capital (to risk-weighted assets)
Cass Information Systems, Inc. 247,354 13.84 107,226 6.00 N/AN/A
Cass Commercial Bank 194,446 16.56 70,433 6.00 93,911 8.00 
Tier I capital (to average assets)
Cass Information Systems, Inc. 247,354 10.57 93,625 4.00 N/AN/A
Cass Commercial Bank 194,446 13.50 57,620 4.00 72,026 5.00