Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 69,021	$ 68,445	$ 199,042	$ 195,292
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	(244)	(130)	(136)	887
Net unrealized gains (losses) on other securities	(24,062)	3,815	49,967	(112,632)
Pension loss amortization	223	476	669	1,426
Other comprehensive income (loss)	(24,083)	4,161	50,500	(110,319)
Comprehensive income	44,938	72,606	249,542	84,973
Non-controlling interest expense	836	221	13	246
Comprehensive income attributable to Commerce Bancshares, Inc	$ 44,102	$ 72,385	$ 249,529	$ 84,727