Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 75,094		$ 77,043
Other comprehensive income (loss) before income taxes: [Abstract]
Net change in unrealized gain (loss)	59,387		54,613
Reclassification adjustments included in earnings [Abstract]
Interest revenue, Investment securities, Taxable securities	(179)		(403)
Interest expense, Subordinated debentures	65		83
Net impairment losses recognized in earnings	92		0
Gain on available for sale securities, net	(4,327)		(1,240)
Other comprehensive income before income taxes	55,038		53,053
Federal and state income taxes	21,408	[1]	20,635	[1]
Other comprehensive income, net of income taxes	33,630		32,418
Comprehensive income	108,724		109,461
Comprehensive income attributable to non-controlling interests	251		453
Comprehensive income attributable to BOK Financial Corp. shareholders	$ 108,473		$ 109,008

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