Common Stock (Tables)

3 Months Ended

Mar. 31, 2018

Common Stock [Abstract]

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

Presented below is a summary of the components used to calculate basic and diluted income per share. The Company applies the two-class method of computing income per share, as nonvested share-based awards that contain nonforfeitable rights to dividends are considered securities which participate in undistributed earnings with common stock. The two-class method requires the calculation of separate income per share amounts for the nonvested share-based awards and for common stock. Income per share attributable to common stock is shown in the table below. Nonvested share-based awards are further discussed in Note 12.

	For the Three Months Ended March 31
(In thousands, except per share data)	2018		2017
Basic income per common share:
Net income attributable to Commerce Bancshares, Inc.	$	100,984	$	71,504
Less preferred stock dividends	2,250		2,250
Net income available to common shareholders	98,734		69,254
Less income allocated to nonvested restricted stock	1,121		945
Net income allocated to common stock	$	97,613	$	68,309
Weighted average common shares outstanding	105,634		105,389
Basic income per common share	$	.92	$	.65
Diluted income per common share:
Net income available to common shareholders	$	98,734	$	69,254
Less income allocated to nonvested restricted stock	1,118		942
Net income allocated to common stock	$	97,616	$	68,312
Weighted average common shares outstanding	105,634		105,389
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	332		416
Weighted average diluted common shares outstanding	105,966		105,805
Diluted income per common share	$	.92	$	.65