Fair Value Measurements, Measured On Recurring Basis Significant Unobservable Inputs (Details) (Fair Value, Inputs, Level 3 [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 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	$ 10,093	$ 17,805
Transfer to Level 3 from Level 2	0	0
Purchases and capital calls	0	0
Proceeds from sales	0
Redemptions and distributions	(500)	(2,322)
Other comprehensive gain (loss)	30	118
Balance, end of period	9,623	15,523
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
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
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		(78)
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
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
Transfer to Level 3 from Level 2	0	0
Purchases and capital calls	0	0
Proceeds from sales	0
Redemptions and distributions	0	0
Other comprehensive gain (loss)	0	0
Balance, end of period	4,150	4,712
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
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
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
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
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		4,207
Transfer to Level 3 from Level 2		0
Purchases and capital calls		0
Redemptions and distributions		0
Other comprehensive gain (loss)		(1,787)
Balance, end of period		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
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
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		(2,420)
Residential mortgage loans held for sale [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance, beginning of period	11,856
Transfer to Level 3 from Level 2	243
Purchases and capital calls	0
Proceeds from sales	(5,288)
Redemptions and distributions	0
Other comprehensive gain (loss)	0
Balance, end of period	6,870
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	59
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
Other assets [Member] | Private equity funds [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance, beginning of period	25,627	27,341
Transfer to Level 3 from Level 2	0	0
Purchases and capital calls	380	205
Proceeds from sales	0
Redemptions and distributions	(694)	(1,105)
Other comprehensive gain (loss)	0	0
Balance, end of period	25,565	27,466
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
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	252	1,025
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
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