Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Segment Reporting Information [Line Items]
Net interest revenue from external sources	$ 300,896	$ 316,325	$ 975,505	$ 858,754
Net interest revenue (expense) from internal sources	0	0	0	0
Net interest revenue	300,896	316,325	975,505	858,754
Net loans charged off and provisions for credit losses	7,000	15,000	40,000	15,000
Net interest revenue after provision for credit losses	293,896	301,325	935,505	843,754
Other operating revenue	198,152	189,698	585,066	446,171
Other operating expense	324,313	294,751	948,798	846,024
Net direct contribution	167,735	196,272	571,773	443,901
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	167,735	196,272	571,773	443,901
Federal and state income taxes	33,256	39,681	123,162	92,000
Net income	134,479	156,591	448,611	351,901
Net income (loss) attributable to non-controlling interests	(16)	81	440	57
Net income attributable to BOK Financial Corp. shareholders	134,495	156,510	448,171	351,844
Average assets	49,319,552	45,119,202	47,748,933	47,636,291
Operating Segments [Member] | Commercial [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	298,293	226,016	886,263	546,599
Net interest revenue (expense) from internal sources	(43,829)	(17,951)	(104,543)	(34,983)
Net interest revenue	254,464	208,065	781,720	511,616
Net loans charged off and provisions for credit losses	4,904	(526)	10,980	3,316
Net interest revenue after provision for credit losses	249,560	208,591	770,740	508,300
Other operating revenue	59,153	60,386	184,826	179,501
Other operating expense	81,751	75,490	232,364	210,012
Net direct contribution	226,962	193,487	723,202	477,789
Gain (loss) on financial instruments, net	(11)	4	162	(138)
Change in fair value of mortgage servicing rights	0	0	0	0
Gain (loss) on repossessed assets, net	(268)	(158)	999	(2,880)
Corporate expense allocations	17,834	16,438	56,956	49,285
Net income before taxes	208,849	176,895	667,407	425,486
Federal and state income taxes	50,919	42,761	161,992	103,711
Net income	157,930	134,134	505,415	321,775
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to BOK Financial Corp. shareholders	157,930	134,134	505,415	321,775
Average assets	28,849,597	28,890,429	28,396,982	29,324,596
Operating Segments [Member] | Consumer [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	11,386	17,482	50,360	51,183
Net interest revenue (expense) from internal sources	101,222	26,469	285,020	53,764
Net interest revenue	112,608	43,951	335,380	104,947
Net loans charged off and provisions for credit losses	(73)	1,408	2,240	3,716
Net interest revenue after provision for credit losses	112,681	42,543	333,140	101,231
Other operating revenue	30,716	30,186	93,603	94,236
Other operating expense	54,497	53,236	157,035	154,685
Net direct contribution	88,900	19,493	269,708	40,782
Gain (loss) on financial instruments, net	(9,183)	(21,395)	(24,113)	(95,150)
Change in fair value of mortgage servicing rights	8,039	16,570	11,241	83,165
Gain (loss) on repossessed assets, net	11	0	25	138
Corporate expense allocations	11,920	10,792	35,860	32,994
Net income before taxes	75,847	3,876	221,001	(4,059)
Federal and state income taxes	17,838	906	51,977	(950)
Net income	58,009	2,970	169,024	(3,109)
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to BOK Financial Corp. shareholders	58,009	2,970	169,024	(3,109)
Average assets	9,379,478	10,233,401	9,635,204	10,281,679
Operating Segments [Member] | Wealth Management [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	7,622	34,746	32,977	130,389
Net interest revenue (expense) from internal sources	28,815	(1,162)	106,918	(3,290)
Net interest revenue	36,437	33,584	139,895	127,099
Net loans charged off and provisions for credit losses	9	(22)	(60)	(153)
Net interest revenue after provision for credit losses	36,428	33,606	139,955	127,252
Other operating revenue	123,614	113,113	355,568	224,892
Other operating expense	89,367	79,151	256,265	230,166
Net direct contribution	70,675	67,568	239,258	121,978
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	14,331	12,934	39,265	37,508
Net income before taxes	56,344	54,634	199,993	84,470
Federal and state income taxes	13,315	12,826	47,200	19,897
Net income	43,029	41,808	152,793	64,573
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to BOK Financial Corp. shareholders	43,029	41,808	152,793	64,573
Average assets	14,740,641	13,818,299	13,128,925	17,320,779
Funds Management and Other [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	(16,405)	38,081	5,905	130,583
Net interest revenue (expense) from internal sources	(86,208)	(7,356)	(287,395)	(15,491)
Net interest revenue	(102,613)	30,725	(281,490)	115,092
Net loans charged off and provisions for credit losses	2,160	14,140	26,840	8,121
Net interest revenue after provision for credit losses	(104,773)	16,585	(308,330)	106,971
Other operating revenue	(15,331)	(13,987)	(48,931)	(52,458)
Other operating expense	98,698	86,874	303,134	251,161
Net direct contribution	(218,802)	(84,276)	(660,395)	(196,648)
Gain (loss) on financial instruments, net	9,194	21,391	23,951	95,288
Change in fair value of mortgage servicing rights	(8,039)	(16,570)	(11,241)	(83,165)
Gain (loss) on repossessed assets, net	257	158	(1,024)	2,742
Corporate expense allocations	(44,085)	(40,164)	(132,081)	(119,787)
Net income before taxes	(173,305)	(39,133)	(516,628)	(61,996)
Federal and state income taxes	(48,816)	(16,812)	(138,007)	(30,658)
Net income	(124,489)	(22,321)	(378,621)	(31,338)
Net income (loss) attributable to non-controlling interests	(16)	81	440	57
Net income attributable to BOK Financial Corp. shareholders	(124,473)	(22,402)	(379,061)	(31,395)
Average assets	$ (3,650,164)	$ (7,822,927)	$ (3,412,178)	$ (9,290,763)