Consolidated Statements of Earnings - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Interest and dividend revenue [Abstract]
Loans	$ 1,625,342	$ 1,760,774	$ 1,630,620
Residential mortgage loans held for sale	5,075	5,062	4,341
Trading securities	295,947	288,182	215,994
Investment securities	26,614	30,005	33,822
Available for sale securities	526,587	490,543	387,891
Fair value option securities	3,851	761	7,760
Restricted equity securities	25,213	32,903	29,683
Interest-bearing cash and cash equivalents	22,639	28,234	32,353
Total interest and dividend revenue	2,531,268	2,636,464	2,342,464
Interest Expense, Operating
Deposits	955,771	1,025,729	626,597
Borrowed funds	240,759	390,761	434,735
Subordinated debentures	7,394	9,216	8,952
Total interest expense	1,203,924	1,425,706	1,070,284
Net interest income	1,327,344	1,210,758	1,272,180
Provision for credit losses	2,000	18,000	46,000
Net interest and dividend income after provision for credit losses	1,325,344	1,192,758	1,226,180
Total fees and commissions revenue	800,740	810,023	781,118
Other gains, net	43,757	79,726	56,795
Gain (loss) on derivatives, net	12,281	(22,461)	(9,921)
Gain (loss) on fair value option securities, net	2,618	(256)	(4,292)
Change in fair value of mortgage servicing rights	(13,227)	18,437	(3,115)
Gain (loss) on available-for-sale securities, net	1,961	(45,828)	(30,636)
Total other operating revenue	848,130	839,641	789,949
Other operating expense [Abstract]
Personnel	877,969	811,239	766,610
Business promotion	39,433	33,274	31,796
Charitable contributions to BOKF Foundation	0	13,610	2,707
Professional fees and services	62,179	53,921	55,337
Net occupancy and equipment	131,382	125,328	121,502
FDIC and other insurance	26,406	31,105	30,780
FDIC special assessment	(10,688)	5,521	43,773
Data processing and communications	198,536	187,273	181,365
Printing, postage, and supplies	15,819	15,079	15,225
Amortization of intangible assets	10,620	11,612	13,882
Mortgage banking costs	35,731	34,638	30,524
Other expense	45,469	43,155	39,380
Total other operating expense	1,432,856	1,365,755	1,332,881
Net income before taxes	740,618	666,644	683,248
Federal and state income taxes	162,640	143,091	152,115
Net income	577,978	523,553	531,133
Net income (loss) attributable to Non-controlling interests	(12)	(16)	387
Net income attributable to BOK Financial Corporation shareholders	$ 577,990	$ 523,569	$ 530,746
Earnings per share: [Abstract]
Basic (in dollars per share)	$ 9.17	$ 8.14	$ 8.02
Diluted (in dollars per share)	$ 9.17	$ 8.14	$ 8.02
Average shares used in computation: [Abstract]
Basic (in shares)	62,622,386	63,745,088	65,651,569
Diluted (in shares)	62,622,386	63,745,088	65,651,569
Dividends declared per share (in dollars per share)	$ 2.34	$ 2.22	$ 2.17
Brokerage and trading revenue [Member]
Total fees and commissions revenue	$ 159,742	$ 218,092	$ 240,610
Transaction card revenue [Member]
Total fees and commissions revenue	117,680	108,865	106,858
Fiduciary and asset management revenue [Member]
Total fees and commissions revenue	257,161	230,860	207,318
Deposit service charges and fees [Member]
Total fees and commissions revenue	125,529	118,745	108,514
Mortgage banking revenue [Member]
Total fees and commissions revenue	77,585	74,107	55,698
Other revenue [Member]
Total fees and commissions revenue	$ 63,043	$ 59,354	$ 62,120