Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting Information [Line Items]
Net interest revenue from external sources	$ 322,261	$ 274,018	$ 674,609	$ 542,429
Net interest revenue (expense) from internal sources	0	0	0	0
Net interest revenue	322,261	274,018	674,609	542,429
Net loans charged off and provisions for credit losses	17,000	0	33,000	0
Net interest revenue after provision for credit losses	305,261	274,018	641,609	542,429
Other operating revenue	209,049	168,617	386,914	256,473
Other operating expense	318,673	273,655	624,485	551,273
Net direct contribution	195,637	168,980	404,038	247,629
Gain (loss) on financial instruments, net	0	0	0	0
Change in fair value of mortgage servicing rights	0	0	0	0
Gain (loss) on repossessed assets, net	0	0	0	0
Corporate expense allocations	0	0	0	0
Net income before taxes	195,637	168,980	404,038	247,629
Federal and state income taxes	44,001	36,122	89,906	52,319
Net income	151,636	132,858	314,132	195,310
Net income (loss) attributable to non-controlling interests	328	12	456	(24)
Net income attributable to BOK Financial Corp. shareholders	151,308	132,846	313,676	195,334
Average assets	47,908,107	47,288,534	46,950,607	48,915,764
Operating Segments [Member] | Commercial [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	299,712	172,995	587,970	320,585
Net interest revenue (expense) from internal sources	(39,613)	(6,452)	(60,714)	(17,031)
Net interest revenue	260,099	166,543	527,256	303,554
Net loans charged off and provisions for credit losses	6,000	(1,502)	6,076	3,841
Net interest revenue after provision for credit losses	254,099	168,045	521,180	299,713
Other operating revenue	68,828	61,688	125,673	119,115
Other operating expense	77,479	69,631	150,613	134,521
Net direct contribution	245,448	160,102	496,240	284,307
Gain (loss) on financial instruments, net	231	61	173	(143)
Change in fair value of mortgage servicing rights	0	0	0	0
Gain (loss) on repossessed assets, net	408	(4,515)	1,267	(2,722)
Corporate expense allocations	21,404	16,617	39,122	32,847
Net income before taxes	224,683	139,031	458,558	248,595
Federal and state income taxes	54,504	33,916	111,073	60,951
Net income	170,179	105,115	347,485	187,644
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to BOK Financial Corp. shareholders	170,179	105,115	347,485	187,644
Average assets	28,170,869	29,269,712	28,166,923	29,545,278
Operating Segments [Member] | Consumer [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	17,828	16,784	38,974	33,699
Net interest revenue (expense) from internal sources	95,563	17,002	183,798	27,294
Net interest revenue	113,391	33,786	222,772	60,993
Net loans charged off and provisions for credit losses	1,129	1,196	2,313	2,308
Net interest revenue after provision for credit losses	112,262	32,590	220,459	58,685
Other operating revenue	32,277	30,089	62,887	64,050
Other operating expense	52,340	52,660	102,538	101,449
Net direct contribution	92,199	10,019	180,808	21,286
Gain (loss) on financial instruments, net	(10,257)	(15,860)	(14,930)	(73,755)
Change in fair value of mortgage servicing rights	9,261	17,485	3,202	66,595
Gain (loss) on repossessed assets, net	0	93	14	138
Corporate expense allocations	12,318	10,120	23,940	22,200
Net income before taxes	78,885	1,617	145,154	(7,936)
Federal and state income taxes	18,553	378	34,139	(1,858)
Net income	60,332	1,239	111,015	(6,078)
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to BOK Financial Corp. shareholders	60,332	1,239	111,015	(6,078)
Average assets	9,597,723	10,338,191	9,765,186	10,306,218
Operating Segments [Member] | Wealth Management [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	4,415	39,412	25,355	95,643
Net interest revenue (expense) from internal sources	44,937	(1,665)	78,103	(2,130)
Net interest revenue	49,352	37,747	103,458	93,513
Net loans charged off and provisions for credit losses	(45)	(60)	(69)	(131)
Net interest revenue after provision for credit losses	49,397	37,807	103,527	93,644
Other operating revenue	123,043	86,761	231,954	111,779
Other operating expense	84,859	76,393	166,898	151,012
Net direct contribution	87,581	48,175	168,583	54,411
Gain (loss) on financial instruments, net	0	0	0	0
Change in fair value of mortgage servicing rights	0	0	0	0
Gain (loss) on repossessed assets, net	0	0	0	0
Corporate expense allocations	12,574	12,503	24,934	24,575
Net income before taxes	75,007	35,672	143,649	29,836
Federal and state income taxes	17,690	8,385	33,885	7,070
Net income	57,317	27,287	109,764	22,766
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to BOK Financial Corp. shareholders	57,317	27,287	109,764	22,766
Average assets	12,949,258	16,902,721	12,309,730	19,101,045
Funds Management and Other [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	306	44,827	22,310	92,502
Net interest revenue (expense) from internal sources	(100,887)	(8,885)	(201,187)	(8,133)
Net interest revenue	(100,581)	35,942	(178,877)	84,369
Net loans charged off and provisions for credit losses	9,916	366	24,680	(6,018)
Net interest revenue after provision for credit losses	(110,497)	35,576	(203,557)	90,387
Other operating revenue	(15,099)	(9,921)	(33,600)	(38,471)
Other operating expense	103,995	74,971	204,436	164,291
Net direct contribution	(229,591)	(49,316)	(441,593)	(112,375)
Gain (loss) on financial instruments, net	10,026	15,799	14,757	73,898
Change in fair value of mortgage servicing rights	(9,261)	(17,485)	(3,202)	(66,595)
Gain (loss) on repossessed assets, net	(408)	4,422	(1,281)	2,584
Corporate expense allocations	(46,296)	(39,240)	(87,996)	(79,622)
Net income before taxes	(182,938)	(7,340)	(343,323)	(22,866)
Federal and state income taxes	(46,746)	(6,557)	(89,191)	(13,844)
Net income	(136,192)	(783)	(254,132)	(9,022)
Net income (loss) attributable to non-controlling interests	328	12	456	(24)
Net income attributable to BOK Financial Corp. shareholders	(136,520)	(795)	(254,588)	(8,998)
Average assets	$ (2,809,743)	$ (9,222,090)	$ (3,291,232)	$ (10,036,777)