Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
	Oct. 28, 2025	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Dividends declared (in dollars per share)		$ 0.57	$ 0.55	$ 1.71	$ 1.65
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, beginning of period		$ 5,893,356	$ 5,231,970	$ 5,550,957	$ 5,145,419
Net change in unrealized gain (loss)		73,209	341,185	333,866	263,436
Interest revenue, Investment securities		8,642	11,431	27,280	35,641
Loss (gain) on available-for-sale securities, net		(213)	691	(213)	45,828
Other comprehensive income, before income taxes		81,638	353,307	360,933	344,905
Federal and state income taxes		19,292	83,094	84,557	81,094
Other comprehensive income, net of income taxes		62,346	270,213	276,376	263,811
Balance, end of period		6,024,925	5,615,198	6,024,925	5,615,198
Accumulated Net Unrealized Gain (Loss) on Available for Sale Securities [Member]
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, beginning of period				(412,348)	(473,212)
Net change in unrealized gain (loss)				333,866	263,436
Interest revenue, Investment securities				0	0
Loss (gain) on available-for-sale securities, net				(213)	45,828
Other comprehensive income, before income taxes				333,653	309,264
Federal and state income taxes				78,244	72,711
Other comprehensive income, net of income taxes				255,409	236,553
Balance, end of period		(156,939)	(236,659)	(156,939)	(236,659)
AOCI, Accumulated Gain (Loss), Debt Securities, Investment Securities Transferred from Available-for-sale, Parent
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, beginning of period				(90,692)	(125,888)
Net change in unrealized gain (loss)				0	0
Interest revenue, Investment securities				27,280	35,641
Loss (gain) on available-for-sale securities, net				0	0
Other comprehensive income, before income taxes				27,280	35,641
Federal and state income taxes				6,313	8,383
Other comprehensive income, net of income taxes				20,967	27,258
Balance, end of period		(69,725)	(98,630)	(69,725)	(98,630)
Accumulated Other Comprehensive Income (Loss) [Member]
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, beginning of period		(289,010)	(605,502)	(503,040)	(599,100)
Net change in unrealized gain (loss)				333,866	263,436
Interest revenue, Investment securities				27,280	35,641
Loss (gain) on available-for-sale securities, net				(213)	45,828
Other comprehensive income, before income taxes				360,933	344,905
Federal and state income taxes				84,557	81,094
Other comprehensive income, net of income taxes		62,346	270,213	276,376	263,811
Balance, end of period		$ (226,664)	$ (335,289)	$ (226,664)	$ (335,289)
Subsequent Event [Member] \| O2025Q4DividendsMember
Dividends Payable, Date Declared	Oct. 28, 2025
Dividends Payable, Amount Per Share	$ 0.63
Dividends Payable, Date to be Paid	Nov. 26, 2025
Dividends Payable, Date of Record	Nov. 12, 2025

BOK FINANCIAL CORP 10-Q