Common Stock (Tables)

3 Months Ended

Mar. 31, 2012

Common Stock [Abstract]

Summary Of Components Used To Calculate Basic And Diluted Income Per Share

	For the Three Months Ended March 31
(In thousands, except per share data)	2012		2011
Basic income per common share:
Net income attributable to Commerce Bancshares, Inc.	$	65,799	$	60,453
Less income allocated to nonvested restricted stockholders	562		404
Net income available to common stockholders	$	65,237	$	60,049
Distributed income	$	20,247	$	19,907
Undistributed income	$	44,990	$	40,142
Weighted average common shares outstanding	88,221		90,791
Distributed income per share	$	.23	$	.22
Undistributed income per share	.51		.44
Basic income per common share	$	.74	$	.66
Diluted income per common share:
Net income attributable to Commerce Bancshares, Inc.	$	65,799	$	60,453
Less income allocated to nonvested restricted stockholders	561		403
Net income available to common stockholders	$	65,238	$	60,050
Distributed income	$	20,247	$	19,907
Undistributed income	$	44,991	$	40,143
Weighted average common shares outstanding	88,221		90,791
Net effect of the assumed exercise of stock-based awards - based on
the treasury stock method using the average market price for the respective periods	335		387
Weighted average diluted common shares outstanding	88,556		91,178
Distributed income per share	$	.23	$	.22
Undistributed income per share	.51		.44
Diluted income per common share	$	.74	$	.66