Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017		Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 85,790	$ 75,112	$ 263,320		$ 182,372
Other comprehensive income (loss) before income taxes:
Net change in unrealized gain (loss)	512	(33,458)	33,881		133,108
Reclassification adjustments included in earnings:
Interest revenue, Investment securities, Taxable securities	0	0	0		(112)
Gain on available for sale securities, net	(2,487)	(2,394)	(4,916)		(11,684)
Other comprehensive income (loss) before income taxes	(1,975)	(35,852)	28,965		121,312
Federal and state income taxes	(768)	(13,947)	11,241	[1]	47,172	[1]
Other comprehensive income (loss), net of income taxes	(1,207)	(21,905)	17,724		74,140
Comprehensive income	84,583	53,207	281,044		256,512
Comprehensive income (loss) attributable to non-controlling interests	141	835	1,168		(270)
Comprehensive income attributable to BOK Financial Corp. shareholders	$ 84,442	$ 52,372	$ 279,876		$ 256,782

[1] Calculated using a 39 percent effective tax rate.