Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 570,699	$ 534,401	$ 485,177
Other comprehensive income (loss):
Net unrealized gains (losses) on other securities	257,855	172,075	209,914
Change in pension loss	2,436	1,537	3,590
Unrealized gains (losses) on cash flow hedge derivatives	(9,070)	(41,111)	(18,052)
Current period other comprehensive income (loss), net of tax	251,221	132,501	195,452
Comprehensive income (loss)	821,920	666,902	680,629
Non-controlling interest expense (income)	4,448	8,070	8,117
Comprehensive income (loss) attributable to Commerce Bancshares, Inc.	$ 817,472	$ 658,832	$ 672,512