Federal and State Income Taxes (Tables)

9 Months Ended

Sep. 30, 2014

Income Tax Disclosure [Abstract]

Reconciliation of income (loss) to income tax expense

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2014			2013			2014			2013
Amount:
Federal statutory tax	$	37,802		$	38,333		$	117,778		$	128,446
Tax exempt revenue	(2,164		)	(1,860		)	(6,254		)	(5,405		)
Effect of state income taxes, net of federal benefit	2,328			2,072			7,655			8,572
Utilization of tax credits	(2,746		)	(1,669		)	(8,213		)	(5,217		)
Bank-owned life insurance	(806		)	(871		)	(2,358		)	(2,749		)
Reduction of tax accrual	(2,281		)	(1,400		)	(2,281		)	(1,400		)
Charitable contributions to BOKF Foundation	—			(1,115		)	(427		)	(1,115		)
Other, net	(254		)	(29		)	710			848
Total	$	31,879		$	33,461		$	106,610		$	121,980

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2014		2013		2014		2013
Percent of pretax income:
Federal statutory tax	35	%	35	%	35	%	35	%
Tax exempt revenue	(2	)	(2	)	(2	)	(1	)
Effect of state income taxes, net of federal benefit	3		2		3		2
Utilization of tax credits	(3	)	(1	)	(2	)	(1	)
Bank-owned life insurance	(1	)	(1	)	(1	)	(1	)
Reduction of tax accrual	(2	)	(1	)	(1	)	(1	)
Charitable contributions to BOKF Foundation	—		(1	)	—		—
Other, net	—		—		—		—
Total	30	%	31	%	32	%	33	%