v3.26.1
Common Stock (Summary Of Components Used To Calculate Basic And Diluted Income Per Share) (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]        
Basic income per common share $ 1.10 $ 1.09 $ 2.06 $ 2.02
Diluted income per common share $ 1.10 $ 1.09 $ 2.06 $ 2.02
Basic income per common share:        
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]        
Net income attributable to Commerce Bancshares, Inc. $ 159,790 $ 152,479 $ 301,413 $ 284,071
Less income allocated to nonvested restricted stock awards 1,405 1,461 2,719 2,720
Net Income (Loss) Available to Common Stockholders, Basic $ 158,385 $ 151,018 $ 298,694 $ 281,351
Weighted average common shares outstanding 144,215 139,077 144,996 139,319
Basic income per common share $ 1.10 $ 1.09 $ 2.06 $ 2.02
Diluted income per common share:        
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]        
Net income attributable to Commerce Bancshares, Inc. $ 159,790 $ 152,479 $ 301,413 $ 284,071
Less income allocated to nonvested restricted stock awards 1,405 1,460 2,718 2,718
Net Income (Loss) Available to Common Stockholders, Diluted $ 158,385 $ 151,019 $ 298,695 $ 281,353
Weighted average common shares outstanding 144,215 139,077 144,996 139,319
Net effect of the assumed exercise of stock-based awards - based on the treasury stock method using the average market price for the respective periods 94 135 83 148
Weighted average diluted common shares outstanding 144,309 139,212 145,079 139,467
Diluted income per common share $ 1.10 $ 1.09 $ 2.06 $ 2.02