Other Borrowings (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Other Borrowings [Line Items]
Balance	$ 3,053,854,000		$ 2,769,748,000		$ 3,516,059,000
Average balance	3,104,724,000		2,678,641,000		4,251,467,000
Weighted Average Interest Rate During Period	0.65%		1.07%		0.98%
Repurchase Agreements, Security Sold/Maturity [Abstract]
Amortized Cost	1,213,593,000		1,583,958,000
Market Value	1,242,314,000		1,628,547,000
Repurchase Liability	877,382,000	[1]	1,231,426,000	[1]
Average Rate (in hundredths)	0.07%		0.09%
Overnight [Member]
Repurchase Agreements, Security Sold/Maturity [Abstract]
Amortized Cost	1,213,593,000		1,583,958,000
Market Value	1,242,314,000		1,628,547,000
Repurchase Liability	877,382,000	[1]	1,231,426,000	[1]
Average Rate (in hundredths)	0.07%		0.09%
Long-term [Member]
Repurchase Agreements, Security Sold/Maturity [Abstract]
Amortized Cost	0		0
Market Value	0		0
Repurchase Liability	0	[1]	0	[1]
Average Rate (in hundredths)	0.00%		0.00%
Parent Company and other non-bank subsidiaries [Member]
Other Borrowings [Line Items]
Balance	10,500,000		0		7,217,000
Average balance	394,000		7,093,000		7,217,000
Weighted Average Interest Rate During Period	1.11%		0.00%		6.42%
Other borrowings, Maturities [Abstract]
Other borrowings, Maturities, 2013	10,500,000
Other borrowings, Maturities, 2014	0
Other borrowings, Maturities, 2015	0
Other borrowings, Maturities, 2016	0
Other borrowings, Maturities, 2017	0
Other borrowings, Maturities, Thereafter	0
Senior Unsecured Revolving Credit Facility [Abstract]
Senior unsecured revolving credit facility, revolving period	364
Parent Company and other non-bank subsidiaries [Member] | Senior Unsecured Revolving Credit Facility [Member]
Other Borrowings [Line Items]
Balance	0		0
Other borrowings, Other Disclosures [Abstract]
Maturity date	Jun. 07, 2013
Senior Unsecured Revolving Credit Facility [Abstract]
Senior unsecured revolving credit facility, borrowing capacity	100,000,000
Senior unsecured revolving credit facility, interest rate description	defined base rate minus 1.25% or LIBOR plus 1.25% based upon the Company’s option
Senior unsecured revolving credit facility, Term loan, interest rate description	defined base rate minus 1.25% or LIBOR plus 1.50%
Senior unsecured revolving credit facility, unused capacity, commitment fee percentage	0.20%
Parent Company and other non-bank subsidiaries [Member] | Trust Preferred Debt [Member]
Other Borrowings [Line Items]
Balance	0		0		7,217,000
Weighted Average Interest Rate	0.00%		0.00%		6.54%
Average balance	0		7,093,000		7,217,000
Weighted Average Interest Rate During Period	0.00%		0.00%		6.42%
Maximum Outstanding At Any Month End	0		8,763,000		7,217,000
Parent Company and other non-bank subsidiaries [Member] | Other [Member]
Other Borrowings [Line Items]
Balance	10,500,000		0		0
Weighted Average Interest Rate	1.50%		0.00%		0.00%
Average balance	394,000		0		0
Weighted Average Interest Rate During Period	1.11%		0.00%		0.00%
Maximum Outstanding At Any Month End	10,500,000		0		0
Subsidiary Bank [Member]
Other Borrowings [Line Items]
Balance	3,043,354,000		2,769,748,000		3,508,842,000
Average balance	3,104,330,000		2,671,548,000		4,244,250,000
Weighted Average Interest Rate During Period	0.65%		1.06%		0.95%
Other borrowings, Maturities [Abstract]
Other borrowings, Maturities, 2013	2,679,914,000
Other borrowings, Maturities, 2014	525,000
Other borrowings, Maturities, 2015	121,829,000
Other borrowings, Maturities, 2016	525,000
Other borrowings, Maturities, 2017	525,000
Other borrowings, Maturities, Thereafter	240,036,000
Subsidiary Bank [Member] | Other [Member]
Other Borrowings [Line Items]
Balance	16,332,000		16,566,000		24,564,000
Weighted Average Interest Rate	5.10%		5.10%		1.75%
Average balance	16,577,000		28,777,000		22,364,000
Weighted Average Interest Rate During Period	2.91%		3.23%		0.46%
Maximum Outstanding At Any Month End	16,761,000		45,366,000		25,326,000
Subsidiary Bank [Member] | Funds Purchased [Member]
Other Borrowings [Line Items]
Balance	1,167,416,000		1,063,318,000		1,025,018,000
Weighted Average Interest Rate	0.05%		0.03%		0.11%
Average balance	1,512,711,000		1,046,114,000		1,185,742,000
Weighted Average Interest Rate During Period	0.14%		0.07%		0.11%
Maximum Outstanding At Any Month End	1,810,793,000		1,706,893,000		1,465,983,000
Other borrowings, Other Disclosures [Abstract]
Number of days to maturity, minimum	1 day
Number of days to maturity, maximum	90 days
Subsidiary Bank [Member] | Repurchase Agreements [Member]
Other Borrowings [Line Items]
Balance	887,030,000		1,233,064,000		1,258,762,000
Weighted Average Interest Rate	0.07%		0.09%		0.78%
Average balance	1,072,650,000		1,096,615,000		1,130,082,000
Weighted Average Interest Rate During Period	0.09%		0.12%		0.59%
Maximum Outstanding At Any Month End	1,272,151,000		1,393,237,000		1,258,762,000
Other borrowings, Other Disclosures [Abstract]
Number of days to maturity, maximum	90 days
Accrued interest payable	0		0
Subsidiary Bank [Member] | Federal Home Loan Bank Advances [Member]
Other Borrowings [Line Items]
Balance	604,897,000		4,837,000		801,797,000
Weighted Average Interest Rate	0.23%		0.27%		0.13%
Average balance	104,925,000		45,110,000		1,446,482,000
Weighted Average Interest Rate During Period	0.31%		0.38%		0.14%
Maximum Outstanding At Any Month End	604,897,000		201,674,000		2,277,977,000
Other borrowings, Other Disclosures [Abstract]
Unused credit available pursuant to the FHLB's collateral policies	685,000,000
Federal Home Loan Banks, Letters of Credit Issued to Secure Public Funds	411,000,000
Subsidiary Bank [Member] | Federal Reserve Advances [Member]
Other Borrowings [Line Items]
Balance					0
Weighted Average Interest Rate					0.00%
Average balance					60,961,000
Weighted Average Interest Rate During Period					0.00%
Maximum Outstanding At Any Month End					400,000,000
Subsidiary Bank [Member] | Subordinated Debentures [Member]
Other Borrowings [Line Items]
Balance	347,633,000		398,881,000		398,701,000
Weighted Average Interest Rate	2.40%		5.47%		5.47%
Average balance	363,699,000		398,790,000		398,619,000
Weighted Average Interest Rate During Period	3.79%		5.74%		5.78%
Maximum Outstanding At Any Month End	398,897,000		398,881,000		398,701,000
Subsidiary Bank [Member] | Subordinated Debentures, 2007 Issuance [Member]
Other Borrowings [Line Items]
Balance	227,000,000		250,000,000
Other borrowings, Other Disclosures [Abstract]
Amount of debt issuance	250,000,000
Maturity date	May 15, 2017
Interest rate description	fixed rate of 5.75% through May 14, 2012 and is based on a floating rate of three-month LIBOR plus 0.69% thereafter
Subsidiary Bank [Member] | Subordinated Debentures, 2005 Issuance [Member]
Other Borrowings [Line Items]
Balance	122,000,000		150,000,000
Weighted Average Interest Rate	5.56%
Other borrowings, Other Disclosures [Abstract]
Amount of debt issuance	150,000,000
Maturity date	Jun. 01, 2015
Subsidiary Bank [Member] | GNMA Repurchase Liability [Member]
Other Borrowings [Line Items]
Balance	20,046,000		53,082,000		0
Weighted Average Interest Rate	5.44%		6.18%		0.00%
Average balance	33,768,000		56,142,000		0
Weighted Average Interest Rate During Period	5.41%		5.79%		0.00%
Maximum Outstanding At Any Month End	$ 47,840,000		$ 118,595,000		$ 0

[1] 1 BOK Financial maintains control over the securities underlying overnight repurchase agreements and generally transfers control over securities underlying longer-term dealer repurchase agreements to the respective counterparty.