Fair Value Measurements, Measured On Recurring Basis Significant Unobservable Inputs (Details) - Fair Value, Measurements, Recurring [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Available-for-sale securities [Member] | Municipal and other tax-exempt securities [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance, beginning of period	$ 9,623	$ 15,523	$ 10,093	$ 17,805
Transfer to Level 3 from Level 2	0	0	0	0
Purchases and capital calls	0	0	0	0
Proceeds from sales	0		0
Redemptions and distributions	0	(5,165)	(500)	(7,487)
Other comprehensive gain (loss)	(6)	244	24	362
Balance, end of period	9,617	10,445	9,617	10,445
Available-for-sale securities [Member] | Municipal and other tax-exempt securities [Member] | Mortgage banking revenue [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0		0
Available-for-sale securities [Member] | Municipal and other tax-exempt securities [Member] | Gain (loss) on assets [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0	0	0	0
Available-for-sale securities [Member] | Municipal and other tax-exempt securities [Member] | Gain on available for sale securities, net [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings		(157)		(235)
Available-for-sale securities [Member] | Municipal and other tax-exempt securities [Member] | Charitable contributions to BOKF Foundation [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings		0		0
Available-for-sale securities [Member] | Other debt securities [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance, beginning of period	4,150	4,712	4,150	4,712
Transfer to Level 3 from Level 2	0	0	0	0
Purchases and capital calls	0	0	0	0
Proceeds from sales	0		0
Redemptions and distributions	0	(500)	0	(500)
Other comprehensive gain (loss)	0	19	0	19
Balance, end of period	4,150	4,231	4,150	4,231
Available-for-sale securities [Member] | Other debt securities [Member] | Mortgage banking revenue [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0		0
Available-for-sale securities [Member] | Other debt securities [Member] | Gain (loss) on assets [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0	0	0	0
Available-for-sale securities [Member] | Other debt securities [Member] | Gain on available for sale securities, net [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings		0		0
Available-for-sale securities [Member] | Other debt securities [Member] | Charitable contributions to BOKF Foundation [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings		0		0
Available-for-sale securities [Member] | Equity securities and mutual funds [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance, beginning of period		0		4,207
Transfer to Level 3 from Level 2		0		0
Purchases and capital calls		0		0
Redemptions and distributions		0		0
Other comprehensive gain (loss)		0		(1,787)
Balance, end of period		0		0
Available-for-sale securities [Member] | Equity securities and mutual funds [Member] | Gain (loss) on assets [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings		0		0
Available-for-sale securities [Member] | Equity securities and mutual funds [Member] | Gain on available for sale securities, net [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings		0		0
Available-for-sale securities [Member] | Equity securities and mutual funds [Member] | Charitable contributions to BOKF Foundation [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings		0		(2,420)
Residential mortgage loans held for sale [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance, beginning of period	6,870		11,856
Transfer to Level 3 from Level 2	944		1,187
Purchases and capital calls	0		0
Proceeds from sales	0		(5,288)
Redemptions and distributions	0		0
Other comprehensive gain (loss)	0		0
Balance, end of period	7,973		7,973
Residential mortgage loans held for sale [Member] | Mortgage banking revenue [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	159		218
Residential mortgage loans held for sale [Member] | Gain (loss) on assets [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0		0
Other assets [Member] | Private equity funds [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance, beginning of period	25,565	27,466	25,627	27,341
Transfer to Level 3 from Level 2	0	0	0	0
Purchases and capital calls	218	220	598	425
Proceeds from sales	0		0
Redemptions and distributions	(2,656)	(2,075)	(3,350)	(3,180)
Other comprehensive gain (loss)	0	0	0	0
Balance, end of period	24,399	27,834	24,399	27,834
Other assets [Member] | Private equity funds [Member] | Mortgage banking revenue [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0		0
Other assets [Member] | Private equity funds [Member] | Gain (loss) on assets [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	$ 1,272	2,223	$ 1,524	3,248
Other assets [Member] | Private equity funds [Member] | Gain on available for sale securities, net [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings		0		0
Other assets [Member] | Private equity funds [Member] | Charitable contributions to BOKF Foundation [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings		$ 0		$ 0