Loans and Allowances for Credit Losses Part 2 (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011	Dec. 31, 2010
Allowance for loan losses [Roll Forward]
Beginning balance	$ 253,481,000		$ 292,971,000	$ 292,095,000
Provision for loan losses	(14,654,000)		(1,040,000)	105,256,000
Loans charged off	(42,138,000)		(56,800,000)	(123,988,000)
Recoveries	18,818,000		18,350,000	19,608,000
Ending balance	215,507,000		253,481,000	292,971,000
Accrual for off-balance sheet credit losses [Roll Forward]
Beginning balance	9,261,000		14,271,000	14,388,000
Provision for off-balance sheet credit losses	(7,346,000)		(5,010,000)	(117,000)
Ending balance	1,915,000		9,261,000	14,271,000
Total provision for credit losses	(22,000,000)		(6,050,000)	105,139,000
Negative recovery related to invalidated settlement agreement	7,100,000
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	12,177,046,000		11,093,254,000
Individually measured for impairment, recorded investment	134,410,000		176,489,000
Total	12,311,456,000		11,269,743,000
Related allowance [Abstract]
Collectively measured for impairment, related allowance	167,087,000		201,355,000
Individually measured for impairment, related allowance	(4,233,000)		(5,776,000)
Total measured for impairment, related allowance	(215,507,000)		(253,481,000)	(292,971,000)
Commercial [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	83,443,000		104,631,000	121,320,000
Provision for loan losses	(14,950,000)		(13,830,000)	1,688,000
Loans charged off	(9,341,000)		(14,836,000)	(27,640,000)
Recoveries	6,128,000	[1]	7,478,000	9,263,000
Ending balance	65,280,000		83,443,000	104,631,000
Accrual for off-balance sheet credit losses [Roll Forward]
Beginning balance	7,906,000		13,456,000	12,344,000
Provision for off-balance sheet credit losses	(7,431,000)		(5,550,000)	1,112,000
Ending balance	475,000		7,906,000	13,456,000
Total provision for credit losses	(22,381,000)		(19,380,000)	2,800,000
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	7,617,445,000		6,486,311,000
Individually measured for impairment, recorded investment	24,467,000		68,759,000
Total	7,641,912,000		6,555,070,000
Related allowance [Abstract]
Collectively measured for impairment, related allowance	65,050,000		81,907,000
Individually measured for impairment, related allowance	(230,000)		(1,536,000)
Total measured for impairment, related allowance	(65,280,000)		(83,443,000)	(104,631,000)
Commercial Real Estate [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	67,034,000		98,709,000	104,208,000
Provision for loan losses	(6,214,000)		(18,482,000)	51,284,000
Loans charged off	(11,642,000)		(15,973,000)	(59,962,000)
Recoveries	5,706,000		2,780,000	3,179,000
Ending balance	54,884,000		67,034,000	98,709,000
Accrual for off-balance sheet credit losses [Roll Forward]
Beginning balance	1,250,000		443,000	1,404,000
Provision for off-balance sheet credit losses	103,000		807,000	(961,000)
Ending balance	1,353,000		1,250,000	443,000
Total provision for credit losses	(6,111,000)		(17,675,000)	50,323,000
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	2,168,373,000		2,192,110,000
Individually measured for impairment, recorded investment	60,626,000		99,193,000
Total	2,228,999,000		2,291,303,000
Related allowance [Abstract]
Collectively measured for impairment, related allowance	51,775,000		63,092,000
Individually measured for impairment, related allowance	(3,109,000)		(3,942,000)
Total measured for impairment, related allowance	(54,884,000)		(67,034,000)	(98,709,000)
Residential Mortgage [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	46,476,000		50,281,000	27,863,000
Provision for loan losses	3,346,000		7,968,000	41,573,000
Loans charged off	(10,047,000)		(14,107,000)	(20,056,000)
Recoveries	1,928,000		2,334,000	901,000
Ending balance	41,703,000		46,476,000	50,281,000
Accrual for off-balance sheet credit losses [Roll Forward]
Beginning balance	91,000		131,000	222,000
Provision for off-balance sheet credit losses	(13,000)		(40,000)	(91,000)
Ending balance	78,000		91,000	131,000
Total provision for credit losses	3,333,000		7,928,000	41,482,000
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	1,998,432,000		1,967,086,000
Individually measured for impairment, recorded investment	46,608,000		7,441,000
Total	2,045,040,000		1,974,527,000
Related allowance [Abstract]
Collectively measured for impairment, related allowance	40,934,000		46,178,000
Individually measured for impairment, related allowance	(769,000)		(298,000)
Total measured for impairment, related allowance	(41,703,000)		(46,476,000)	(50,281,000)
Consumer [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	10,178,000		12,614,000	20,452,000
Provision for loan losses	5,327,000		3,690,000	2,227,000
Loans charged off	(11,108,000)		(11,884,000)	(16,330,000)
Recoveries	5,056,000		5,758,000	6,265,000
Ending balance	9,453,000		10,178,000	12,614,000
Accrual for off-balance sheet credit losses [Roll Forward]
Beginning balance	14,000		241,000	418,000
Provision for off-balance sheet credit losses	(5,000)		(227,000)	(177,000)
Ending balance	9,000		14,000	241,000
Total provision for credit losses	5,322,000		3,463,000	2,050,000
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	392,796,000		447,747,000
Individually measured for impairment, recorded investment	2,709,000		1,096,000
Total	395,505,000		448,843,000
Related allowance [Abstract]
Collectively measured for impairment, related allowance	9,328,000		10,178,000
Individually measured for impairment, related allowance	(125,000)		0
Total measured for impairment, related allowance	(9,453,000)		(10,178,000)	(12,614,000)
Segment Allocations [Member]
Allowance for loan losses [Roll Forward]
Ending balance	171,320,000		207,131,000
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	12,177,046,000		11,093,254,000
Individually measured for impairment, recorded investment	134,410,000		176,489,000
Total	12,311,456,000		11,269,743,000
Related allowance [Abstract]
Collectively measured for impairment, related allowance	167,087,000		201,355,000
Individually measured for impairment, related allowance	(4,233,000)		(5,776,000)
Total measured for impairment, related allowance	(171,320,000)		(207,131,000)
Unallocated Financing Receivables [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	46,350,000		26,736,000	18,252,000
Provision for loan losses	(2,163,000)		19,614,000	8,484,000
Loans charged off	0		0	0
Recoveries	0		0	0
Ending balance	44,187,000		46,350,000	26,736,000
Accrual for off-balance sheet credit losses [Roll Forward]
Beginning balance	0		0	0
Provision for off-balance sheet credit losses	0		0	0
Ending balance	0		0	0
Total provision for credit losses	(2,163,000)		19,614,000	8,484,000
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	0		0
Individually measured for impairment, recorded investment	0		0
Total	0		0
Related allowance [Abstract]
Collectively measured for impairment, related allowance	0		0
Individually measured for impairment, related allowance	0		0
Total measured for impairment, related allowance	$ (44,187,000)		$ (46,350,000)	$ (26,736,000)

[1] Includes $7.1 million of negative recovery related to a refund of a settlement between BOK Financial and the City of Tulsa invalidated by the Oklahoma Supreme Court.