Consolidated Statements of Earnings (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Interest revenue
Loans	$ 513,429	$ 504,989	$ 522,559
Residential mortgage loans held for sale	8,185	6,492	9,261
Trading securities	1,419	1,836	2,172
Investment securities, Taxable securities	16,848	12,581	7,229
Investment securities, Tax-exempt securities	3,577	4,768	6,402
Total investment securities	20,425	17,349	13,631
Available for sale securities, Taxable securities	237,235	259,871	283,583
Available for sale securities, Tax-exempt securities	2,487	2,394	2,446
Total available for sale securities	239,722	262,265	286,029
Fair value option securities	8,456	18,649	17,403
Funds sold and resell agreements	12	15	27
Total interest revenue	791,648	811,595	851,082
Interest expense
Deposits	67,013	88,890	106,265
Borrowed funds	6,531	8,826	13,334
Subordinated debentures	13,778	22,385	22,431
Total interest expense	87,322	120,101	142,030
Net interest revenue	704,326	691,494	709,052
Provision for credit losses	(22,000)	(6,050)	105,139
Net interest revenue after provision for credit losses	726,326	697,544	603,913
Other operating revenue
Brokerage and trading revenue	126,930	104,181	101,471
Transaction card revenue	107,985	116,757	112,302
Trust fees and commissions	80,053	73,290	68,976
Deposit service charges and fees	98,917	95,872	103,611
Mortgage banking revenue	169,302	91,643	87,600
Bank-owned life insurance	11,089	11,280	12,066
Other revenue	37,827	35,620	30,368
Total fees and commissions	632,103	528,643	516,394
Gain (loss) on assets, net	(1,415)	4,156	(4,011)
Gain (loss) on derivatives, net	(301)	2,686	4,271
Gain on fair value option securities, net	9,230	24,413	7,331
Gain on available for sale securities, net	33,845	34,144	21,882
Total other-than-temporary impairment losses	(1,144)	(10,578)	(29,960)
Portion of loss recognized in (reclassified from) other comprehensive income	(6,207)	(12,929)	2,151
Net impairment losses recognized in earnings	(7,351)	(23,507)	(27,809)
Total other operating revenue	666,111	570,535	518,058
Other operating expense
Personnel	491,033	429,986	401,864
Business promotion	23,338	20,549	17,726
Contribution to BOKF Foundation	2,062	4,000	0
Professional fees and services	34,015	28,798	30,217
Net occupancy and equipment	66,726	64,611	63,969
Insurance	15,356	16,799	24,320
Data processing and communications	98,904	97,976	87,752
Printing, postage and supplies	14,228	14,085	13,665
Net losses and expenses of repossessed assets	20,528	23,715	34,483
Amortization of intangible assets	2,927	3,583	5,336
Mortgage banking costs	44,334	37,621	43,172
Change in fair value of mortgage servicing rights	9,210	40,447	(3,661)
Other expense	26,912	37,574	31,477
Total other operating expense	849,573	819,744	750,320
Income before taxes	542,864	448,335	371,651
Federal and state income tax	188,740	158,511	123,357
Net income	354,124	289,824	248,294
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	2,933	3,949	1,540
Net income attributable to non-controlling interest	2,933	3,949	1,540
Net income attributable to BOK Financial Corp. shareholders	$ 351,191	$ 285,875	$ 246,754
Earnings per share:
Basic (in dollars per share)	$ 5.15	$ 4.18	$ 3.63
Diluted (in dollars per share)	$ 5.13	$ 4.17	$ 3.61
Average shares used in computation:
Basic (in shares)	67,684,043	67,787,676	67,627,735
Diluted (in shares)	67,964,940	68,038,763	67,831,734
Dividends declared per share (in dollars per share)	$ 2.47	$ 1.13	$ 0.99