Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Numerator: [Abstract]
Net income attributable to BOK Financial Corporation shareholders	$ 75,895	$ 79,931	$ 152,485	$ 167,895
Less: Earnings allocated to participating securities	884	854	1,579	1,825
Numerator for basic earnings per share - income available to common shareholders	75,011	79,077	150,906	166,070
Effect of reallocating undistributed earnings of participating securities	1	2	2	4
Numerator for diluted earnings per share - income available to common shareholders	$ 75,012	$ 79,079	$ 150,908	$ 166,074
Denominator: [Abstract]
Weighted average shares outstanding (in shares)	69,162,724	68,719,694	69,031,961	68,645,247
Less: Participating securities included in weighted average shares (in shares)	802,779	725,872	713,272	740,648
Denominator for basic earnings per common share (in shares)	68,359,945	67,993,822	68,318,689	67,904,599
Dilutive effect of employee stock compensation plans (in shares)	151,433	218,675	157,113	222,152
Denominator for diluted earnings per common share (in shares)	68,511,378	68,212,497	68,475,802	68,126,751
Basic earnings per share (per share)	$ 1.10	$ 1.16	$ 2.21	$ 2.45
Diluted earnings per share (per share)	$ 1.10	$ 1.16	$ 2.20	$ 2.44
Excludes employee stock options with exercise prices greater than current market price.	0	0	0	0