Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Statement of Other Comprehensive Income [Abstract]
Net income	$ 66,039	$ 71,236	$ 126,847	$ 138,050
Available for sale debt securities for which a portion of an other-than-temporary impairment (OTTI) has been recorded in earnings:
Net unrealized gains (losses) on OTTI securities	(120)	537	1,017	3,897
Other available for sale investment securities:
Net unrealized gains on other securities	(108,254)	17,686	(116,447)	21,392
Prepaid pension cost:
Pension loss amortization	475	453	950	905
Other comprehensive income	(107,899)	18,676	(114,480)	26,194
Comprehensive income	(41,860)	89,912	12,367	164,244
Non-controlling interest expense	(234)	(503)	(25)	(1,518)
Comprehensive income attributable to Commerce Bancshares, Inc	$ (42,094)	$ 89,409	$ 12,342	$ 162,726

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