Capital Requirements and Regulatory Restrictions (Tables)

12 Months Ended

Dec. 31, 2013

Capital Requirements and Regulatory Restrictions [Abstract]

Schedule of Capital Amounts and Ratios

The Company's and the Bank's actual and required capital amounts and ratios as are as follows:

					Capital				Requirement to be
	Actual				Requirements				Well-Capitalized
(In thousands)	Amount		Ratio		Amount		Ratio		Amount		Ratio
At December 31, 2013
Total capital (to risk-weighted assets)
Cass Information Systems, Inc.	$	191,984	22.27	%	$	68,956	8.00	%	$	N/A	N/A	%
Cass Commercial Bank		83,168	15.38			43,256	8.00			54,071	10.00
Tier I capital (to risk-weighted assets)
Cass Information Systems, Inc.		181,198	21.02			34,478	4.00			N/A	N/A
Cass Commercial Bank		76,395	14.13			21,628	4.00			32,442	6.00
Tier I capital (to average assets)
Cass Information Systems, Inc.		181,198	13.12			41,438	3.00			N/A	N/A
Cass Commercial Bank		76,395	11.37			20,162	3.00			33,603	5.00
At December 31, 2012
Total capital (to risk-weighted assets)
Cass Information Systems, Inc.	$	175,802	19.87	%	$	70,767	8.00	%	$	N/A	N/A	%
Cass Commercial Bank		75,300	13.41			44,909	8.00			56,136	10.00
Tier I capital (to risk-weighted assets)
Cass Information Systems, Inc.		164,729	18.62			35,384	4.00			N/A	N/A
Cass Commercial Bank		68,261	12.16			22,454	4.00			33,682	6.00
Tier I capital (to average assets)
Cass Information Systems, Inc.		164,729	12.26			40,294	3.00			N/A	N/A
Cass Commercial Bank		68,261	10.64			19,238	3.00			32,063	5.00