Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Segment Reporting Information [Line Items]
Net interest revenue from external sources	$ 316,325	$ 280,227	$ 858,754	$ 840,956
Net interest revenue (expense) from internal sources	0	0	0	0
Net interest revenue	316,325	280,227	858,754	840,956
Provision for credit losses	15,000	(23,000)	15,000	(83,000)
Net interest revenue after provision for credit losses	301,325	303,227	843,754	923,956
Other operating revenue	189,698	229,832	446,171	598,332
Other operating expense	294,751	291,277	846,024	878,213
Net direct contribution	196,272	241,782	443,901	644,075
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	196,272	241,782	443,901	644,075
Federal and state income taxes	39,681	54,061	92,000	144,939
Net income	156,591	187,721	351,901	499,136
Net income (loss) attributable to non-controlling interests	81	(601)	57	(1,667)
Net income attributable to BOK Financial Corp. shareholders	156,510	188,322	351,844	500,803
Average assets	45,119,202	49,499,149	47,636,291	49,999,262
Operating Segments [Member] | Commercial [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	224,855	150,211	545,438	457,953
Net interest revenue (expense) from internal sources	(17,951)	(16,107)	(34,983)	(62,941)
Net interest revenue	206,904	134,104	510,455	395,012
Provision for credit losses	(526)	2,807	3,316	33,061
Net interest revenue after provision for credit losses	207,430	131,297	507,139	361,951
Other operating revenue	60,386	92,511	179,501	204,358
Other operating expense	75,872	68,301	210,995	206,630
Net direct contribution	191,944	155,507	475,645	359,679
Gain (loss) on financial instruments, net	4	44	(138)	111
Change in fair value of mortgage servicing rights	0	0	0	0
Gain (loss) on repossessed assets, net	(158)	(3,945)	(2,880)	12,355
Corporate expense allocations	16,451	11,769	49,331	37,015
Net income before taxes	175,339	139,837	423,296	335,130
Federal and state income taxes	42,398	37,143	103,198	90,130
Net income	132,941	102,694	320,098	245,000
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to BOK Financial Corp. shareholders	132,941	102,694	320,098	245,000
Average assets	28,890,429	28,474,132	29,324,596	28,228,824
Operating Segments [Member] | Consumer [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	17,482	16,967	51,183	51,205
Net interest revenue (expense) from internal sources	26,469	10,255	53,764	21,936
Net interest revenue	43,951	27,222	104,947	73,141
Provision for credit losses	1,408	928	3,716	2,489
Net interest revenue after provision for credit losses	42,543	26,294	101,231	70,652
Other operating revenue	30,186	44,401	94,236	134,396
Other operating expense	53,236	49,483	154,685	157,558
Net direct contribution	19,493	21,212	40,782	47,490
Gain (loss) on financial instruments, net	(21,395)	(5,949)	(95,150)	(18,427)
Change in fair value of mortgage servicing rights	16,570	12,945	83,165	33,778
Gain (loss) on repossessed assets, net	0	0	138	41
Corporate expense allocations	10,792	11,516	32,994	34,590
Net income before taxes	3,876	16,692	(4,059)	28,292
Federal and state income taxes	906	4,260	(950)	7,214
Net income	2,970	12,432	(3,109)	21,078
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to BOK Financial Corp. shareholders	2,970	12,432	(3,109)	21,078
Average assets	10,233,401	10,083,593	10,281,679	9,976,742
Operating Segments [Member] | Wealth Management [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	34,746	55,697	130,389	157,217
Net interest revenue (expense) from internal sources	(1,162)	(501)	(3,290)	(1,375)
Net interest revenue	33,584	55,196	127,099	155,842
Provision for credit losses	(22)	(70)	(153)	(153)
Net interest revenue after provision for credit losses	33,606	55,266	127,252	155,995
Other operating revenue	113,113	97,888	224,892	243,160
Other operating expense	79,151	87,498	230,166	245,685
Net direct contribution	67,568	65,656	121,978	153,470
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	12,934	10,110	37,508	30,358
Net income before taxes	54,634	55,546	84,470	123,112
Federal and state income taxes	12,826	14,207	19,897	31,488
Net income	41,808	41,339	64,573	91,624
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to BOK Financial Corp. shareholders	41,808	41,339	64,573	91,624
Average assets	13,818,299	19,109,704	17,320,779	18,987,236
Funds Management and Other [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	39,242	57,352	131,744	174,581
Net interest revenue (expense) from internal sources	(7,356)	6,353	(15,491)	42,380
Net interest revenue	31,886	63,705	116,253	216,961
Provision for credit losses	14,140	(26,665)	8,121	(118,397)
Net interest revenue after provision for credit losses	17,746	90,370	108,132	335,358
Other operating revenue	(13,987)	(4,968)	(52,458)	16,418
Other operating expense	86,492	85,995	250,178	268,340
Net direct contribution	(82,733)	(593)	(194,504)	83,436
Gain (loss) on financial instruments, net	21,391	5,905	95,288	18,316
Change in fair value of mortgage servicing rights	(16,570)	(12,945)	(83,165)	(33,778)
Gain (loss) on repossessed assets, net	158	3,945	2,742	(12,396)
Corporate expense allocations	(40,177)	(33,395)	(119,833)	(101,963)
Net income before taxes	(37,577)	29,707	(59,806)	157,541
Federal and state income taxes	(16,449)	(1,549)	(30,145)	16,107
Net income	(21,128)	31,256	(29,661)	141,434
Net income (loss) attributable to non-controlling interests	81	(601)	57	(1,667)
Net income attributable to BOK Financial Corp. shareholders	(21,209)	31,857	(29,718)	143,101
Average assets	$ (7,822,927)	$ (8,168,280)	$ (9,290,763)	$ (7,193,540)