Parent Company Only Financial Statements Parent Company Only Financial Statements, Condensed Income Statements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Condensed Income Statements, Captions [Line Items]
Interest expense	$ 1,070,284	$ 180,722	$ 61,896
Other operating expense	1,332,881	1,164,480	1,177,708
Other gains (losses), net	56,795	123	63,742
Federal and state income taxes	152,115	139,864	179,775
Net income attributable to BOK Financial Corp. shareholders	530,746	520,273	618,121
Parent Company [Member]
Condensed Income Statements, Captions [Line Items]
Total revenue	338,591	273,142	492,665
Interest expense	8,952	6,490	10,535
Other operating expense	5,674	3,005	2,914
Total expense	14,626	9,495	13,449
Net income before taxes, other losses, net, and equity in undistributed income of subsidiaries	323,965	263,647	479,216
Other gains (losses), net	32,656	(4,279)	(3,415)
Net income before taxes and equity in undistributed income of subsidiaries	356,621	259,368	475,801
Federal and state income taxes	5,410	(1,776)	(4,202)
Net income before equity in undistributed income of subsidiaries	351,211	261,144	480,003
Equity in undistributed income of bank subsidiaries	181,487	300,330	126,380
Equity in undistributed income of non-bank subsidiaries	(1,952)	(41,201)	11,738
Net income attributable to BOK Financial Corp. shareholders	530,746	520,273	618,121
Parent Company [Member] | Dividends, interest and fees received from bank susidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Total revenue	329,429	228,689	483,868
Parent Company [Member] | Dividends, interest and fees received from non-bank subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Total revenue	8,000	43,281	8,030
Parent Company [Member] | Other revenue [Member]
Condensed Income Statements, Captions [Line Items]
Total revenue	$ 1,162	$ 1,172	$ 767