Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020		Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 64,286	$ 137,780	$ 126,270		$ 248,045
Other Comprehensive Income (Loss), before Tax [Abstract]
Net change in unrealized gain (loss)	56,922	135,417	354,765		228,156
Reclassification Adjustments Included in Earnings [Abstract]
Gain on available for sale securities, net	(5,577)	(1,029)	(5,580)		(1,105)
Other comprehensive income before income taxes	51,345	134,388	349,185		227,051
Federal and state income taxes	12,321	32,288	83,792	[1]	55,897	[1]
Other comprehensive income, net of income taxes	39,024	102,100	265,393		171,154
Comprehensive income	103,310	239,880	391,663		419,199
Comprehensive income (loss) attributable to non-controlling interests	(407)	217	(502)		(130)
Comprehensive income attributable to BOK Financial Corp. shareholders	$ 103,717	$ 239,663	$ 392,165		$ 419,329

[1] Calculated using a 25 percent blended federal and state statutory tax rate.