Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Numerator: [Abstract]
Net income attributable to BOK Financial Corp. shareholders	$ 74,277	$ 74,891	$ 182,642	$ 228,964
Less: Earnings allocated to participating securities	916	894	2,275	2,652
Numerator for basic earnings per share – income available to common shareholders	73,361	73,997	180,367	226,312
Effect of reallocating undistributed earnings of participating securities	1	1	1	2
Numerator for diluted earnings per share – income available to common shareholders	$ 73,362	$ 73,998	$ 180,368	$ 226,314
Denominator: [Abstract]
Weighted average shares outstanding (in shares)	65,895,430	68,486,376	66,031,497	68,800,419
Less: Participating securities included in weighted average shares (in shares)	810,038	818,300	822,723	795,911
Denominator for basic earnings per common share (in shares)	65,085,392	67,668,076	65,208,774	68,004,508
Dilutive effect of employee stock compensation plans (in shares)	72,449	94,407	54,792	99,509
Denominator for diluted earnings per common share (in shares)	65,157,841	67,762,483	65,263,566	68,104,017
Basic earnings per share (per share)	$ 1.13	$ 1.09	$ 2.77	$ 3.33
Diluted earnings per share (per share)	$ 1.13	$ 1.09	$ 2.76	$ 3.32
1 Excludes employee stock options with exercise prices greater than current market price.	0	0	0	0