Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 62,014us-gaap_ProfitLoss	$ 64,121us-gaap_ProfitLoss
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	(128)	166
Net unrealized gains (losses) on other securities	29,346	30,379
Pension loss amortization	406	223
Other comprehensive income (loss)	29,624	30,768
Comprehensive income	91,638	94,889
Non-controlling interest expense	959	(192)
Comprehensive income attributable to Commerce Bancshares, Inc	$ 90,679us-gaap_ComprehensiveIncomeNetOfTax	$ 95,081us-gaap_ComprehensiveIncomeNetOfTax

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income (loss) and other comprehensive income (loss), attributable to noncontrolling interests. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount after tax, before reclassification adjustments, of unrealized holding gain (loss) on available-for-sale securities.

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Amount after tax of other than temporary impairment (OTTI) loss on investments in available-for-sale and held-to-maturity debt securities, recognized in other comprehensive loss.

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The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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