Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 78,989	$ 69,808	$ 150,691	$ 135,330
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	76	0	171	(398)
Net unrealized gains (losses) on other securities	11,241	31,139	30,243	101,634
Pension loss amortization	341	356	681	718
Other comprehensive income (loss), net of tax	11,658	31,495	31,095	101,954
Comprehensive income	90,647	101,303	181,786	237,284
Non-controlling interest expense (income)	29	(85)	227	63
Comprehensive income attributable to Commerce Bancshares, Inc	$ 90,618	$ 101,388	$ 181,559	$ 237,221