Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash Flows From Operating Activities: [Abstract]
Net income	$ 523,553	$ 531,133	$ 520,293
Adjustments to reconcile net income to net cash provided by (used in) operating activities: [Abstract]
Provision for credit losses	18,000	46,000	30,000
Change in fair value of mortgage servicing rights due to market changes	(18,437)	3,115	(80,261)
Change in fair value of mortgage servicing rights due to principal payments	30,807	27,343	31,741
Net unrealized losses (gains) from derivative contracts	(173,247)	133,118	(52,214)
Share-based compensation	22,883	16,350	11,564
Depreciation and amortization	105,306	109,893	107,563
Net amortization of discounts and premiums	(45,069)	(19,985)	9,215
Net losses (gains) on financial instruments and other losses (gains), net	(33,898)	(26,162)	846
Net loss (gain) on mortgage loans held for sale	(7,625)	4,483	(2,948)
Mortgage loans originated for sale	(812,263)	(666,391)	(1,180,403)
Proceeds from sale of mortgage loans held for sale	800,376	679,389	1,295,588
Capitalized mortgage servicing rights	(14,976)	(12,141)	(18,215)
Charitable contributions to BOKF Foundation	13,610	0	0
Change in trading and fair value option securities	297,198	(453,340)	4,419,761
Change in receivables	321,945	(316,819)	(34,301)
Change in other assets	106,972	89,930	13,205
Change in other liabilities	295,319	(79,733)	50,836
Net cash provided by (used in) operating activities	1,430,454	66,183	5,122,270
Cash Flows From Investing Activities: [Abstract]
Proceeds from maturities or redemptions of investment securities	224,077	268,263	157,796
Proceeds from maturities or redemptions of available for sale securities	2,138,581	1,558,160	2,192,200
Purchases of investment securities	0	(2,504)	(10,000)
Purchases of available for sale securities	(3,467,059)	(2,951,422)	(4,533,892)
Proceeds from sales of available for sale securities	839,352	834,704	307,481
Change in amount receivable on unsettled available for sale securities transactions	100,758	(86,110)	9,629
Loans originated, net of principal collected	(195,624)	(1,349,900)	(2,348,586)
Net payments or proceeds on derivative asset contracts	12,204	154,602	(7,099)
Proceeds from sale of BOKF Insurance	0	32,601	0
Net change in restricted equity securities		123,448	216,538
Net change in restricted equity securities	16,921
Proceeds from disposition of assets	25,147	39,708	60,769
Purchases of assets	(171,589)	(165,918)	(215,046)
Net cash provided by (used in) investing activities	(477,232)	(1,791,264)	(4,603,286)
Cash Flows From Financing Activities: [Abstract]
Net change in demand deposits, transaction deposits and savings accounts	3,648,141	(2,011,184)	(6,518,868)
Net change in time deposits	523,388	1,550,180	(242,486)
Net change in other borrowed funds	(4,526,879)	1,802,549	4,609,824
Change in amount due on unsettled security purchases	(180,074)	190,085	(17,782)
Issuance of common and treasury stock, net	(3,764)	(4,941)	(4,907)
Net change in derivative margin accounts	(81,284)	631,433	519,797
Net payments or proceeds on derivative liability contracts	(13,477)	(166,275)	(1,569)
Repurchase of common stock	(89,856)	(176,819)	(154,887)
Dividends paid	(142,981)	(143,398)	(143,800)
Net cash provided by (used in) financing activities	(866,786)	1,671,630	(1,954,678)
Net increase (decrease) in cash and cash equivalents	86,436	(53,451)	(1,435,694)
Cash and cash equivalents at beginning of period	1,348,265	1,401,716	2,837,410
Cash and cash equivalents at end of period	1,434,701	1,348,265	1,401,716
Supplemental Cash Flow Information: [Abstract]
Cash paid for interest	1,428,059	1,044,950	176,081
Cash paid for taxes	100,512	173,916	79,532
Net loans and bank premises transferred to repossessed real estate and other assets	462	787	12,326
Transfer of available for sale securities to investment securities, Fair Value	0	0	2,454,273
Residential mortgage loans guaranteed by U.S. government agencies that became eligible for repurchase during the period	25,558	14,466	34,259
Conveyance of other real estate owned guaranteed by U.S. government agencies	3,848	5,534	8,451
Right-of-use assets obtained in exchange for operating lease liabilities	$ 19,100	$ 71,865	$ 22,059