Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Numerator: [Abstract]
Net income attributable to BOK Financial Corporation shareholders	$ 76,590	$ 87,964
Earnings allocated to participating securities	698	971
Numerator for basic earnings per share - income available to common shareholders	75,892	86,993
Effect of reallocating undistributed earnings of participating securities	1	5
Numerator for diluted earnings per share - income available to common shareholders	$ 75,893	$ 86,998
Denominator: [Abstract]
Weighted average shares outstanding (in shares)	68,899,746	68,569,475
Less: Participating securities included in weighted average shares (in shares)	626,061	754,925
Denominator for basic earnings per common share (in shares)	68,273,685	67,814,550
Dilutive effect of employee stock compensation plans (in shares)	162,793	225,630
Denominator for diluted earnings per common share (in shares)	68,436,478	68,040,180
Basic earnings per share (per share)	$ 1.11	$ 1.28
Diluted earnings per share (per share)	$ 1.11	$ 1.28
Excludes employee stock options with exercise prices greater than current market price.	0	87,377