Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 438,214	$ 319,900	$ 276,854
Other comprehensive income (loss):
Net unrealized gains (losses) on securities for which a portion of an other-than-temporary impairment has been recorded in earnings	(277)	412	(341)
Net unrealized gains (losses) on other securities	(55,631)	3,022	(22,422)
Change in pension loss	664	(301)	1,268
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	6,855	0	0
Other comprehensive income (loss)	(48,389)	3,133	(21,495)
Comprehensive income	389,825	323,033	255,359
Non-controlling interest expense	4,672	517	1,463
Comprehensive income attributable to Commerce Bancshares, Inc.	$ 385,153	$ 322,516	$ 253,896