Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 49,603	$ 97,055
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	0	41
Net unrealized gains (losses) on other securities	78,672	73,441
Pension loss amortization	356	389
Unrealized gains (losses) on cash flow hedge derivatives	63,664	2,779
Other comprehensive income (loss), net of tax	142,692	76,650
Comprehensive income	192,295	173,705
Non-controlling interest expense (income)	(2,254)	(83)
Comprehensive income attributable to Commerce Bancshares, Inc	$ 194,549	$ 173,788