Reportable Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Net interest and dividend revenue from external sources	$ 1,272,180	$ 1,211,380	$ 1,118,033
Net interest revenue (expense) from internal sources	0	0	0
Net interest and dividend revenue	1,272,180	1,211,380	1,118,033
Provision for credit losses	46,000	30,000	(100,000)
Net interest and dividend revenue after provision for credit losses	1,226,180	1,181,380	1,218,033
Other operating revenue	789,949	643,257	755,775
Other operating expense	1,332,881	1,164,480	1,177,708
Net direct contribution	683,248	660,157	796,100
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	683,248	660,157	796,100
Federal and state income taxes	152,115	139,864	179,775
Net income	531,133	520,293	616,325
Net income (loss) attributable to Non-controlling interests	387	20	(1,796)
Net income attributable to BOK Financial Corp. shareholders	530,746	520,273	618,121
Average assets	48,244,154	47,024,636	50,151,703
Operating Segments [Member] | Commercial [Member]
Segment Reporting Information [Line Items]
Net interest and dividend revenue from external sources	1,179,336	818,213	606,902
Net interest revenue (expense) from internal sources	(146,965)	(73,764)	(71,167)
Net interest and dividend revenue	1,032,371	744,449	535,735
Provision for credit losses	13,967	17,726	31,128
Net interest and dividend revenue after provision for credit losses	1,018,404	726,723	504,607
Other operating revenue	246,225	241,594	262,402
Other operating expense	312,794	289,243	279,571
Net direct contribution	951,835	679,074	487,438
Gain (loss) on financial instruments, net	378	1	154
Change in fair value of mortgage servicing rights	0	0	0
Gain (loss) on repossessed assets, net	398	(1,903)	13,001
Corporate expense allocations	74,976	67,278	54,146
Net income before taxes	877,635	609,894	446,447
Federal and state income taxes	213,174	148,358	119,934
Net income	664,461	461,536	326,513
Net income (loss) attributable to Non-controlling interests	0	0	0
Net income attributable to BOK Financial Corp. shareholders	664,461	461,536	326,513
Average assets	28,630,716	29,084,957	28,536,881
Operating Segments [Member] | Consumer [Member]
Segment Reporting Information [Line Items]
Net interest and dividend revenue from external sources	59,985	69,646	67,856
Net interest revenue (expense) from internal sources	389,791	88,603	35,671
Net interest and dividend revenue	449,776	158,249	103,527
Provision for credit losses	5,157	5,260	4,009
Net interest and dividend revenue after provision for credit losses	444,619	152,989	99,518
Other operating revenue	123,678	121,819	173,341
Other operating expense	212,114	209,210	209,596
Net direct contribution	356,183	65,598	63,263
Gain (loss) on financial instruments, net	(14,806)	(93,346)	(21,871)
Change in fair value of mortgage servicing rights	(3,115)	80,261	41,637
Gain (loss) on repossessed assets, net	36	139	85
Corporate expense allocations	48,565	44,965	46,010
Net income before taxes	289,733	7,687	37,104
Federal and state income taxes	68,143	1,798	9,461
Net income	221,590	5,889	27,643
Net income (loss) attributable to Non-controlling interests	0	0	0
Net income attributable to BOK Financial Corp. shareholders	221,590	5,889	27,643
Average assets	9,561,512	10,230,437	10,029,687
Operating Segments [Member] | Wealth Management [Member]
Segment Reporting Information [Line Items]
Net interest and dividend revenue from external sources	39,198	155,974	214,458
Net interest revenue (expense) from internal sources	142,340	5,623	(386)
Net interest and dividend revenue	181,538	161,597	214,072
Provision for credit losses	(50)	(175)	(223)
Net interest and dividend revenue after provision for credit losses	181,588	161,772	214,295
Other operating revenue	506,447	339,501	298,962
Other operating expense	352,540	312,377	320,726
Net direct contribution	335,495	188,896	192,531
Gain (loss) on financial instruments, net	0	4	0
Change in fair value of mortgage servicing rights	0	0	0
Gain (loss) on repossessed assets, net	0	0	0
Corporate expense allocations	53,463	50,241	40,341
Net income before taxes	282,032	138,659	152,190
Federal and state income taxes	66,549	32,639	38,944
Net income	215,483	106,020	113,246
Net income (loss) attributable to Non-controlling interests	0	0	0
Net income attributable to BOK Financial Corp. shareholders	215,483	106,020	113,246
Average assets	13,570,153	16,209,684	19,425,475
Funds Management and Other [Member]
Segment Reporting Information [Line Items]
Net interest and dividend revenue from external sources	(6,339)	167,547	228,817
Net interest revenue (expense) from internal sources	(385,166)	(20,462)	35,882
Net interest and dividend revenue	(391,505)	147,085	264,699
Provision for credit losses	26,926	7,189	(134,914)
Net interest and dividend revenue after provision for credit losses	(418,431)	139,896	399,613
Other operating revenue	(86,401)	(59,657)	21,070
Other operating expense	455,433	353,650	367,815
Net direct contribution	(960,265)	(273,411)	52,868
Gain (loss) on financial instruments, net	14,428	93,341	21,717
Change in fair value of mortgage servicing rights	3,115	(80,261)	(41,637)
Gain (loss) on repossessed assets, net	(434)	1,764	(13,086)
Corporate expense allocations	(177,004)	(162,484)	(140,497)
Net income before taxes	(766,152)	(96,083)	160,359
Federal and state income taxes	(195,751)	(42,931)	11,436
Net income	(570,401)	(53,152)	148,923
Net income (loss) attributable to Non-controlling interests	387	20	(1,796)
Net income attributable to BOK Financial Corp. shareholders	(570,788)	(53,172)	150,719
Average assets	$ (3,518,227)	$ (8,500,442)	$ (7,840,340)