Reportable Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Net interest and dividend revenue from external sources	$ 1,118,033	$ 1,108,444	$ 1,112,879
Net interest revenue (expense) from internal sources	0	0	0
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
Other operating revenue	755,775	842,320	695,233
Other operating expense	1,177,708	1,164,308	1,133,244
Net direct contribution	796,100	563,864	630,868
Gain (loss) on financial instruments, net	0	0	0
Change in fair value of mortgage servicing rights	0	0	0
Gain (loss) on repossessed assets, net	0	0	0
Corporate expense allocations	0	0	0
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 Corp. shareholders	618,121	435,030	500,758
Average assets	50,151,703	48,704,390	42,094,347
Operating Segments [Member] | Commercial [Member]
Segment Reporting Information [Line Items]
Net interest and dividend revenue from external sources	606,902	714,932	919,148
Net interest revenue (expense) from internal sources	(71,167)	(126,444)	(242,907)
Net interest and dividend revenue	535,735	588,488	676,241
Provision for credit losses	31,128	69,475	39,011
Net interest and dividend revenue after provision for credit losses	504,607	519,013	637,230
Other operating revenue	262,402	187,361	170,412
Other operating expense	281,089	258,903	252,459
Net direct contribution	485,920	447,471	555,183
Gain (loss) on financial instruments, net	154	193	106
Change in fair value of mortgage servicing rights	0	0	0
Gain (loss) on repossessed assets, net	13,001	(2,677)	331
Corporate expense allocations	49,941	24,862	43,055
Net income before taxes	449,134	420,125	512,565
Federal and state income taxes	120,618	114,120	137,759
Net income	328,516	306,005	374,806
Net income (loss) attributable to Non-controlling interests	0	0	0
Net income attributable to BOK Financial Corp. shareholders	328,516	306,005	374,806
Average assets	28,536,881	26,994,075	22,807,589
Operating Segments [Member] | Consumer [Member]
Segment Reporting Information [Line Items]
Net interest and dividend revenue from external sources	67,856	78,004	99,679
Net interest revenue (expense) from internal sources	35,671	69,000	95,775
Net interest and dividend revenue	103,527	147,004	195,454
Provision for credit losses	4,009	2,805	6,271
Net interest and dividend revenue after provision for credit losses	99,518	144,199	189,183
Other operating revenue	173,341	243,719	187,500
Other operating expense	209,596	230,402	226,346
Net direct contribution	63,263	157,516	150,337
Gain (loss) on financial instruments, net	(21,871)	95,344	30,375
Change in fair value of mortgage servicing rights	41,637	(79,524)	(53,517)
Gain (loss) on repossessed assets, net	85	276	496
Corporate expense allocations	46,010	42,155	46,926
Net income before taxes	37,104	131,457	80,765
Federal and state income taxes	9,461	33,483	20,572
Net income	27,643	97,974	60,193
Net income (loss) attributable to Non-controlling interests	0	0	0
Net income attributable to BOK Financial Corp. shareholders	27,643	97,974	60,193
Average assets	10,029,687	9,842,114	9,301,341
Operating Segments [Member] | Wealth Management [Member]
Segment Reporting Information [Line Items]
Net interest and dividend revenue from external sources	214,458	130,818	61,277
Net interest revenue (expense) from internal sources	(386)	(13,528)	38,815
Net interest and dividend revenue	214,072	117,290	100,092
Provision for credit losses	(223)	(209)	(308)
Net interest and dividend revenue after provision for credit losses	214,295	117,499	100,400
Other operating revenue	298,962	398,834	341,389
Other operating expense	320,357	325,627	277,267
Net direct contribution	192,900	190,706	164,522
Gain (loss) on financial instruments, net	0	4	2
Change in fair value of mortgage servicing rights	0	0	0
Gain (loss) on repossessed assets, net	0	0	0
Corporate expense allocations	40,301	35,331	36,239
Net income before taxes	152,599	155,379	128,285
Federal and state income taxes	39,049	39,765	32,954
Net income	113,550	115,614	95,331
Net income (loss) attributable to Non-controlling interests	0	0	0
Net income attributable to BOK Financial Corp. shareholders	113,550	115,614	95,331
Average assets	19,425,475	15,695,646	10,204,426
Funds Management and Other [Member]
Segment Reporting Information [Line Items]
Net interest and dividend revenue from external sources	228,817	184,690	32,775
Net interest revenue (expense) from internal sources	35,882	70,972	108,317
Net interest and dividend revenue	264,699	255,662	141,092
Provision for credit losses	(134,914)	150,521	(974)
Net interest and dividend revenue after provision for credit losses	399,613	105,141	142,066
Other operating revenue	21,070	12,406	(4,068)
Other operating expense	366,666	349,376	377,172
Net direct contribution	54,017	(231,829)	(239,174)
Gain (loss) on financial instruments, net	21,717	(95,541)	(30,483)
Change in fair value of mortgage servicing rights	(41,637)	79,524	53,517
Gain (loss) on repossessed assets, net	(13,086)	2,401	(827)
Corporate expense allocations	(136,252)	(102,348)	(126,220)
Net income before taxes	157,263	(143,097)	(90,747)
Federal and state income taxes	10,647	(58,575)	(61,102)
Net income	146,616	(84,522)	(29,645)
Net income (loss) attributable to Non-controlling interests	(1,796)	41	(73)
Net income attributable to BOK Financial Corp. shareholders	148,412	(84,563)	(29,572)
Average assets	$ (7,840,340)	$ (3,827,445)	$ (219,009)