Consolidated Statements Of Income - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
INTEREST INCOME
Interest and fees on loans		$ 984,397	$ 646,293	$ 570,549
Interest on loans held for sale		583	637	880
Interest on investment securities		278,755	313,892	236,278
Interest on federal funds sold		659	412	4
Interest on securities purchased under agreements to resell		13,649	22,647	37,377
Interest on deposits with banks		103,248	15,098	3,202
Total interest income		1,381,291	998,979	848,290
INTEREST EXPENSE
Savings, interest checking and money market		146,392	25,099	7,509
Certificates of deposit of less than $100,000		38,690	1,469	1,158
Certificates of deposit of $100,000 and over		61,057	3,898	2,577
Interest on federal funds purchased		25,265	1,836	16
Interest on securities sold under agreements to repurchase		73,164	24,022	1,630
Interest on other borrowings		38,594	470	(24)
Total interest expense		383,162	56,794	12,866
Net interest income		998,129	942,185	835,424
Provision for loan losses		35,451	28,071	(66,326)
Net interest income after provision for loan losses		962,678	914,114	901,750
NON-INTEREST INCOME
Bank card transaction fees		191,156	176,144	167,891
Trust fees		190,954	184,719	188,227
Deposit account charges and other fees		90,992	94,381	97,217
Consumer brokerage services		17,223	19,117	18,362
Capital market fees		14,100	14,231	15,943
Loan fees and sales		11,165	13,141	29,720
Other		57,455	44,802	43,033
Total non-interest income		573,045	546,535	560,393
INVESTMENT SECURITIES GAINS (LOSSES), NET
Investment securities gains (losses), net	[1]	14,985	20,506	30,059
NON-INTEREST EXPENSE
Salaries and employee benefits		584,063	554,047	525,248
Data processing and software		118,758	110,692	101,792
Net occupancy		53,629	49,117	48,185
Deposit insurance		33,163	10,583	9,094
Marketing		24,511	23,827	21,856
Equipment		19,548	19,359	18,089
Supplies and communication		19,420	18,101	17,118
Other		77,890	63,051	64,519
Total non-interest expense		930,982	848,777	805,901
Income before income taxes		619,726	632,378	686,301
Less income taxes		134,549	132,358	145,711
Net income		485,177	500,020	540,590
Less non-controlling interest expense (income)		8,117	11,621	9,825
NET INCOME ATTRIBUTABLE TO COMMERCE BANCSHARES, INC.		$ 477,060	$ 488,399	$ 530,765
Net income per common share - basic (in dollars per share)		$ 3.64	$ 3.68	$ 3.92
Net income per common share - diluted (in dollars per share)		$ 3.64	$ 3.67	$ 3.91

[1] Available for sale debt securities, equity securities, and other securities.