Common and Preferred Stock (Tables)

12 Months Ended

Dec. 31, 2017

Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]

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

(In thousands, except per share data)	2017		2016		2015
Basic income per common share:
Net income attributable to Commerce Bancshares, Inc.	$	319,383	$	275,391	$	263,730
Less preferred stock dividends	9,000		9,000		9,000
Net income available to common shareholders	310,383		266,391		254,730
Less income allocated to nonvested restricted stock	3,848		3,698		3,548
Net income allocated to common stock	$	306,535	$	262,693	$	251,182
Weighted average common shares outstanding	105,555		105,243		108,016
Basic income per common share	$	2.90	$	2.50	$	2.33
Diluted income per common share:
Net income available to common shareholders	$	310,383	$	266,391	$	254,730
Less income allocated to nonvested restricted stock	3,838		3,692		3,541
Net income allocated to common stock	$	306,545	$	262,699	$	251,189
Weighted average common shares outstanding	105,555		105,243		108,016
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	372		281		336
Weighted average diluted common shares outstanding	105,927		105,524		108,352
Diluted income per common share	$	2.89	$	2.49	$	2.32

Schedule Of Activity In The Outstanding Shares Of The Company's Common Stock

The table below shows activity in the outstanding shares of the Company’s common stock during the past three years. Shares in the table below are presented on an historical basis and have not been restated for the annual 5% stock dividends.

	Years Ended December 31
(In thousands)	2017		2016		2015
Shares outstanding at January 1	101,461		97,226		96,327
Issuance of stock:
Awards and sales under employee and director plans	403		397		435
5% stock dividend	5,078		4,831		4,641
Purchases of treasury stock under accelerated share repurchase programs	—		—		(3,635	)
Other purchases of treasury stock	(315	)	(959	)	(535	)
Other	(12	)	(34	)	(7	)
Shares outstanding at December 31	106,615		101,461		97,226