Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Numerator: [Abstract]
Net income attributable to BOK Financial Corp. shareholders	$ 65,801	$ 79,230	$ 108,365	$ 154,073
Less: Earnings allocated to participating securities	821	944	1,359	1,758
Numerator for basic earnings per share - income available to common shareholders	64,980	78,286	107,006	152,315
Effect of reallocating undistributed earnings of participating securities	0	1	0	2
Numerator for diluted earnings per share - income available to common shareholders	$ 64,980	$ 78,287	$ 107,006	$ 152,317
Denominator: [Abstract]
Weighted average shares outstanding (in shares)	66,069,392	68,917,977	66,100,279	68,960,043
Less: Participating securities included in weighted average shares (in shares)	823,505	821,636	829,065	784,716
Denominator for basic earnings per common share (in shares)	65,245,887	68,096,341	65,271,214	68,175,327
Dilutive effect of employee stock compensation plans (in shares)	57,039	114,012	45,963	102,059
Denominator for diluted earnings per common share (in shares)	65,302,926	68,210,353	65,317,177	68,277,386
Basic earnings per share (per share)	$ 1.00	$ 1.15	$ 1.64	$ 2.23
Diluted earnings per share (per share)	$ 1.00	$ 1.15	$ 1.64	$ 2.23
Excludes employee stock options with exercise prices greater than current market price.	0	0	145,247	0