Consolidated Statements of Earnings (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Interest revenue [Abstract]
Loans	$ 122,471	$ 125,113
Residential mortgage loans held for sale	1,590	1,792
Trading securities	411	478
Taxable securities	3,282	3,798
Tax-exempt securities	1,504	1,028
Total investment securities	4,786	4,826
Taxable securities	47,255	55,007
Tax-exempt securities	494	604
Total available for sale securities	47,749	55,611
Fair value option securities	851	1,177
Restricted equity securities	997	865
Interest-bearing cash and cash equivalents	265	184
Total interest revenue	179,120	190,046
Interest expense [Abstract]
Deposits	12,986	14,881
Borrowed funds	1,334	1,554
Subordinated debentures	2,158	2,159
Total interest expense	16,478	18,594
Net interest revenue	162,642	171,452
Provision for credit losses	0	(8,000)
Net interest revenue after provision for credit losses	162,642	179,452
Other operating revenue [Abstract]
Brokerage and trading revenue	29,516	31,751
Transaction card revenue	29,134	27,692
Fiduciary and asset management revenue	25,722	22,313
Deposit service charges and fees	22,689	22,966
Mortgage banking revenue	22,844	39,976
Bank-owned life insurance	2,106	3,226
Other revenue	8,852	9,140
Total fees and commissions	140,863	157,064
Gain (loss) on assets, net	(4,264)	467
Gain (loss) on derivatives, net	968	(941)
Gain (loss) on fair value option securities, net	2,660	(3,171)
Change in fair value of mortgage servicing rights	(4,461)	2,658
Gain on available for sale securities, net	1,240	4,855
Total other-than-temporary impairment losses	0	0
Portion of loss recognized in (reclassified from) other comprehensive income	0	(247)
Net impairment losses recognized in earnings	0	(247)
Total other operating revenue	137,006	160,685
Other operating expense [Abstract]
Personnel	104,433	125,654
Business promotion	5,841	5,453
Charitable contributions to BOKF Foundation	2,420	0
Professional fees and services	7,565	6,985
Net occupancy and equipment	16,896	16,481
Insurance	4,541	3,745
Data processing and communications	27,135	25,450
Printing, postage and supplies	3,541	3,674
Net losses and operating expenses of repossessed assets	1,432	1,246
Amortization of intangible assets	816	876
Mortgage banking costs	3,634	7,354
Other expense	6,850	7,064
Total other operating expense	185,104	203,982
Net income before taxes	114,544	136,155
Federal and state income taxes	37,501	47,096
Net income	77,043	89,059
Net income attributable to non-controlling interest	453	1,095
Net income attributable to BOK Financial Corporation shareholders	$ 76,590	$ 87,964
Earnings per share: [Abstract]
Basic (in dollars per share)	$ 1.11	$ 1.28
Diluted (in dollars per share)	$ 1.11	$ 1.28
Average shares used in computation: [Abstract]
Basic (in shares)	68,273,685	67,814,550
Diluted (in shares)	68,436,478	68,040,180
Dividends declared per share (in dollars per share)	$ 0.40	$ 0.38