Consolidated Statements of Changes in Equity (Unaudited) (USD $) In Thousands, except Share data	Common Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Total shareholders' Equity [Member]	Non-Controlling Interest [Member]	Total
Balances at Dec. 31, 2009	$ 4	$ (10,740)	$ 758,723	$ 1,563,683	$ (105,857)	$ 2,205,813	$ 19,561	$ 2,225,374
Balances (in shares) at Dec. 31, 2009	70,312,000				2,509,000
Comprehensive income:
Net income attributable to BOKF	0	0	0	187,922	0	187,922	0	187,922
Net income attributable to non-controlling interest	0	0	0	0	0	0	1,266	1,266
Other comprehensive income, net of tax	0	149,781	0	0	0	149,781	0	149,781
Comprehensive income						337,703	1,266	338,969
Exercise of stock options (in shares)	315,000				27,000
Exercise of stock options	0	0	6,900	0	(3,641)	3,259	0	3,259
Tax benefit on exercise of stock options	0	0	340	0	0	340	0	340
Stock-based compensation	0	0	6,231	0	0	6,231	0	6,231
Cash dividends on common stock	0	0	0	(49,696)	0	(49,696)	0	(49,696)
Capital calls and distributions, net	0	0	0	0	0	0	(489)	(489)
Balances at Sep. 30, 2010	4	139,041	772,194	1,701,909	(109,498)	2,503,650	20,338	2,523,988
Balances (in shares) at Sep. 30, 2010	70,627,000				2,536,000
Balances at Dec. 31, 2010	4	107,839	782,805	1,743,880	(112,802)	2,521,726	22,152	2,543,878
Balances (in shares) at Dec. 31, 2010	70,816,000				2,608,000
Comprehensive income:
Net income attributable to BOKF	0	0	0	218,882	0	218,882	0	218,882
Net income attributable to non-controlling interest	0	0	0	0	0	0	3,038	3,038
Other comprehensive income, net of tax	0	55,732	0	0	0	55,732	0	55,732
Comprehensive income						274,614	3,038	277,652
Treasury stock purchases (in shares)	0				492,000
Treasury stock purchases	0	0	0	0	(22,866)	(22,866)	0	(22,866)
Exercise of stock options (in shares)	338,000				48,000
Exercise of stock options	0	0	8,842	0	(3,161)	5,681	0	5,681
Tax benefit on exercise of stock options	0	0	494	0	0	494	0	494
Stock-based compensation	0	0	7,131	0	0	7,131	0	7,131
Cash dividends on common stock	0	0	0	(54,188)	0	(54,188)	0	(54,188)
Capital calls and distributions, net	0	0	0	0	0	0	9,768	9,768
Balances at Sep. 30, 2011	$ 4	$ 163,571	$ 799,272	$ 1,908,574	$ (138,829)	$ 2,732,592	$ 34,958	$ 2,767,550
Balances (in shares) at Sep. 30, 2011	71,154,000				3,148,000