Consolidated Statements of Earnings - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Interest and dividend revenue [Abstract]
Loans	$ 769,357	$ 889,507	$ 1,123,791
Residential mortgage loans held for sale	5,465	6,397	7,105
Trading securities	155,989	67,689	61,595
Investment securities	10,430	11,943	13,426
Available for sale securities	230,383	261,196	254,031
Fair value option securities	1,542	18,475	32,936
Restricted equity securities	5,703	10,963	26,860
Interest-bearing cash and cash equivalents	1,060	2,830	12,214
Total interest revenue	1,179,929	1,269,000	1,531,958
Interest Expense [Abstract]
Deposits	33,484	89,996	175,538
Borrowed funds	17,877	56,616	228,428
Subordinated debentures	10,535	13,944	15,113
Total interest expense	61,896	160,556	419,079
Net interest and dividend revenue	1,118,033	1,108,444	1,112,879
Provision for credit losses	(100,000)	222,592	44,000
Net interest and dividend revenue after provision for credit losses	1,218,033	885,852	1,068,879
Total fees and commissions	668,309	810,320	702,201
Other gains, net	63,742	6,046	10,214
Gain (loss) on derivatives, net	(19,378)	42,320	14,951
Gain (loss) on fair value option securities, net	(2,239)	53,248	15,787
Change in fair value of mortgage servicing rights	41,637	(79,524)	(53,517)
Gain on available for sale securities, net	3,704	9,910	5,597
Total other operating revenue	755,775	842,320	695,233
Other operating expense [Abstract]
Personnel	695,382	688,474	660,565
Business promotion	16,289	14,511	35,662
Charitable contributions to BOKF Foundation	9,000	9,000	3,000
Professional fees and services	50,906	53,437	54,861
Net occupancy and equipment	108,587	112,722	110,275
Insurance	15,881	19,990	20,906
Data processing and communications	151,614	135,497	124,983
Printing, postage and supplies	14,218	15,061	16,517
Amortization of intangible assets	18,311	20,443	20,618
Mortgage banking costs	42,698	56,711	50,685
Other expense	54,822	38,462	35,172
Total other operating expense	1,177,708	1,164,308	1,133,244
Net income before taxes	796,100	563,864	630,868
Federal and state income taxes	179,775	128,793	130,183
Net income	616,325	435,071	500,685
Net income (loss) attributable to Non-controlling interests	(1,796)	41	(73)
Net income attributable to BOK Financial Corporation shareholders	$ 618,121	$ 435,030	$ 500,758
Earnings per share: [Abstract]
Basic (in dollars per share)	$ 8.95	$ 6.19	$ 7.03
Diluted (in dollars per share)	$ 8.95	$ 6.19	$ 7.03
Average shares used in computation: [Abstract]
Basic (in shares)	68,591,920	69,840,977	70,787,700
Diluted (in shares)	68,594,322	69,844,172	70,802,612
Dividends declared per share (in dollars per share)	$ 2.09	$ 2.05	$ 2.01
Brokerage and trading revenue [Member]
Total fees and commissions	$ 112,989	$ 221,833	$ 159,826
Transaction card revenue [Member]
Total fees and commissions	96,983	90,182	87,216
Fiduciary and asset management revenue [Member]
Total fees and commissions	178,274	167,445	177,025
Deposit service charges and fees [Member]
Total fees and commissions	104,217	96,805	112,485
Mortgage banking revenue [Member]
Total fees and commissions	105,896	182,360	107,541
Other revenue [Member]
Total fees and commissions	$ 69,950	$ 51,695	$ 58,108