Fair Value Measurements (Details) (USD $)																																																6 Months Ended							3 Months Ended		6 Months Ended				3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Jun. 30, 2012 Significant Unobservable Inputs Level 3 Maximum	Jun. 30, 2012 Measured on a Recurring Basis	Dec. 31, 2011 Measured on a Recurring Basis	Jun. 30, 2012 Measured on a Recurring Basis Fair Value	Dec. 31, 2011 Measured on a Recurring Basis Fair Value	Jun. 30, 2012 Measured on a Recurring Basis Fair Value U.S. Treasury	Dec. 31, 2011 Measured on a Recurring Basis Fair Value U.S. Treasury	Jun. 30, 2012 Measured on a Recurring Basis Fair Value Federal agency - Debt	Dec. 31, 2011 Measured on a Recurring Basis Fair Value Federal agency - Debt	Jun. 30, 2012 Measured on a Recurring Basis Fair Value Federal agency - MBS	Dec. 31, 2011 Measured on a Recurring Basis Fair Value Federal agency - MBS	Jun. 30, 2012 Measured on a Recurring Basis Fair Value CMOs - Federal agency	Dec. 31, 2011 Measured on a Recurring Basis Fair Value CMOs - Federal agency	Jun. 30, 2012 Measured on a Recurring Basis Fair Value CMOs - Non-agency	Dec. 31, 2011 Measured on a Recurring Basis Fair Value CMOs - Non-agency	Jun. 30, 2012 Measured on a Recurring Basis Fair Value State and municipal	Dec. 31, 2011 Measured on a Recurring Basis Fair Value State and municipal	Jun. 30, 2012 Measured on a Recurring Basis Fair Value Other debt securities	Dec. 31, 2011 Measured on a Recurring Basis Fair Value Other debt securities	Jun. 30, 2012 Measured on a Recurring Basis Fair Value Equity securities and mutual funds	Dec. 31, 2011 Measured on a Recurring Basis Fair Value Equity securities and mutual funds	Jun. 30, 2012 Measured on a Recurring Basis Quoted Prices in Active Markets Level 1	Dec. 31, 2011 Measured on a Recurring Basis Quoted Prices in Active Markets Level 1	Jun. 30, 2012 Measured on a Recurring Basis Quoted Prices in Active Markets Level 1 U.S. Treasury	Dec. 31, 2011 Measured on a Recurring Basis Quoted Prices in Active Markets Level 1 U.S. Treasury	Jun. 30, 2012 Measured on a Recurring Basis Quoted Prices in Active Markets Level 1 Equity securities and mutual funds	Dec. 31, 2011 Measured on a Recurring Basis Quoted Prices in Active Markets Level 1 Equity securities and mutual funds	Jun. 30, 2012 Measured on a Recurring Basis Significant Other Observable Inputs Level 2	Dec. 31, 2011 Measured on a Recurring Basis Significant Other Observable Inputs Level 2	Jun. 30, 2012 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 Federal agency - Debt	Dec. 31, 2011 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 Federal agency - Debt	Jun. 30, 2012 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 Federal agency - MBS	Dec. 31, 2011 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 Federal agency - MBS	Jun. 30, 2012 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 CMOs - Federal agency	Dec. 31, 2011 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 CMOs - Federal agency	Jun. 30, 2012 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 CMOs - Non-agency	Dec. 31, 2011 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 CMOs - Non-agency	Jun. 30, 2012 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 State and municipal	Dec. 31, 2011 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 State and municipal	Jun. 30, 2012 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 Other debt securities	Dec. 31, 2011 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 Other debt securities	Jun. 30, 2012 Measured on a Recurring Basis Significant Unobservable Inputs Level 3 Y	Dec. 31, 2011 Measured on a Recurring Basis Significant Unobservable Inputs Level 3	Jun. 30, 2012 Measured on a Recurring Basis Significant Unobservable Inputs Level 3 State and municipal	Jun. 30, 2012 Measured on a Recurring Basis Significant Unobservable Inputs Level 3 Other debt securities	Dec. 31, 2011 Measured on a Recurring Basis Significant Unobservable Inputs Level 3 Other debt securities	Jun. 30, 2012 Measured on a Recurring Basis Level 1 or Level 2	Dec. 31, 2011 Measured on a Recurring Basis Level 1 or Level 2	Jun. 30, 2012 Measured on a Nonrecurring Basis	Jun. 30, 2011 Measured on a Nonrecurring Basis	Jun. 30, 2012 Measured on a Nonrecurring Basis	Jun. 30, 2011 Measured on a Nonrecurring Basis	Jun. 30, 2012 Measured on a Nonrecurring Basis Commercial	Jun. 30, 2011 Measured on a Nonrecurring Basis Commercial	Jun. 30, 2012 Measured on a Nonrecurring Basis Commercial real estate mortgages	Jun. 30, 2011 Measured on a Nonrecurring Basis Commercial real estate mortgages	Jun. 30, 2012 Measured on a Nonrecurring Basis Commercial real estate mortgages	Jun. 30, 2011 Measured on a Nonrecurring Basis Commercial real estate mortgages	Jun. 30, 2012 Measured on a Nonrecurring Basis Residential mortgage	Jun. 30, 2011 Measured on a Nonrecurring Basis Residential mortgage	Jun. 30, 2012 Measured on a Nonrecurring Basis Residential mortgage	Jun. 30, 2011 Measured on a Nonrecurring Basis Residential mortgage	Jun. 30, 2012 Measured on a Nonrecurring Basis Real estate construction	Jun. 30, 2011 Measured on a Nonrecurring Basis Real estate construction	Jun. 30, 2012 Measured on a Nonrecurring Basis Real estate construction	Jun. 30, 2011 Measured on a Nonrecurring Basis Real estate construction	Jun. 30, 2012 Measured on a Nonrecurring Basis Equity lines of credit	Jun. 30, 2011 Measured on a Nonrecurring Basis Equity lines of credit	Jun. 30, 2012 Measured on a Nonrecurring Basis Equity lines of credit	Jun. 30, 2011 Measured on a Nonrecurring Basis Equity lines of credit	Jun. 30, 2011 Measured on a Nonrecurring Basis Installment loan	Jun. 30, 2012 Measured on a Nonrecurring Basis Installment loan	Jun. 30, 2011 Measured on a Nonrecurring Basis Installment loan	Jun. 30, 2012 Measured on a Nonrecurring Basis Other real estate owned	Jun. 30, 2011 Measured on a Nonrecurring Basis Other real estate owned	Jun. 30, 2012 Measured on a Nonrecurring Basis Other real estate owned	Jun. 30, 2011 Measured on a Nonrecurring Basis Other real estate owned	Jun. 30, 2012 Measured on a Nonrecurring Basis Private equity and alternative investments	Jun. 30, 2011 Measured on a Nonrecurring Basis Private equity and alternative investments	Jun. 30, 2012 Measured on a Nonrecurring Basis Private equity and alternative investments	Jun. 30, 2011 Measured on a Nonrecurring Basis Private equity and alternative investments	Jun. 30, 2012 Measured on a Nonrecurring Basis Fair Value	Dec. 31, 2011 Measured on a Nonrecurring Basis Fair Value	Jun. 30, 2012 Measured on a Nonrecurring Basis Fair Value Commercial	Dec. 31, 2011 Measured on a Nonrecurring Basis Fair Value Commercial	Jun. 30, 2012 Measured on a Nonrecurring Basis Fair Value Commercial real estate mortgages	Dec. 31, 2011 Measured on a Nonrecurring Basis Fair Value Commercial real estate mortgages	Jun. 30, 2012 Measured on a Nonrecurring Basis Fair Value Residential mortgage	Dec. 31, 2011 Measured on a Nonrecurring Basis Fair Value Residential mortgage	Jun. 30, 2012 Measured on a Nonrecurring Basis Fair Value Real estate construction	Dec. 31, 2011 Measured on a Nonrecurring Basis Fair Value Real estate construction	Jun. 30, 2012 Measured on a Nonrecurring Basis Fair Value Equity lines of credit	Dec. 31, 2011 Measured on a Nonrecurring Basis Fair Value Equity lines of credit	Jun. 30, 2012 Measured on a Nonrecurring Basis Fair Value Installment loan	Dec. 31, 2011 Measured on a Nonrecurring Basis Fair Value Installment loan	Jun. 30, 2012 Measured on a Nonrecurring Basis Fair Value Other real estate owned	Dec. 31, 2011 Measured on a Nonrecurring Basis Fair Value Other real estate owned	Jun. 30, 2012 Measured on a Nonrecurring Basis Fair Value Private equity and alternative investments	Dec. 31, 2011 Measured on a Nonrecurring Basis Fair Value Private equity and alternative investments	Jun. 30, 2012 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2	Dec. 31, 2011 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2	Jun. 30, 2012 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2 Commercial real estate mortgages	Dec. 31, 2011 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2 Commercial real estate mortgages	Jun. 30, 2012 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2 Residential mortgage	Dec. 31, 2011 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2 Residential mortgage	Dec. 31, 2011 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2 Real estate construction	Dec. 31, 2011 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2 Equity lines of credit	Jun. 30, 2012 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2 Installment loan	Dec. 31, 2011 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2 Installment loan	Jun. 30, 2012 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2 Other real estate owned	Dec. 31, 2011 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2 Other real estate owned	Jun. 30, 2012 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3	Dec. 31, 2011 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3	Jun. 30, 2012 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Commercial	Dec. 31, 2011 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Commercial	Jun. 30, 2012 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Commercial real estate mortgages	Jun. 30, 2012 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Residential mortgage	Dec. 31, 2011 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Residential mortgage	Jun. 30, 2012 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Real estate construction	Dec. 31, 2011 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Real estate construction	Jun. 30, 2012 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Equity lines of credit	Dec. 31, 2011 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Equity lines of credit	Jun. 30, 2012 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Other real estate owned	Dec. 31, 2011 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Other real estate owned	Jun. 30, 2012 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Private equity and alternative investments	Dec. 31, 2011 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Private equity and alternative investments
Assets
Securities available-for-sale												$ 17,208,000	$ 19,182,000	$ 999,207,000	$ 1,973,862,000	$ 691,672,000	$ 681,044,000	$ 4,477,264,000	$ 4,326,907,000	$ 65,466,000	$ 69,001,000	$ 383,650,000	$ 401,604,000	$ 229,908,000	$ 99,074,000	$ 1,506,000	$ 1,227,000			$ 17,208,000	$ 19,182,000	$ 1,506,000	$ 1,227,000			$ 999,207,000	$ 1,973,862,000	$ 691,672,000	$ 681,044,000	$ 4,477,264,000	$ 4,326,907,000	$ 65,466,000	$ 69,001,000	$ 336,483,000	$ 401,604,000	$ 210,724,000	$ 79,491,000			$ 47,167,000	$ 19,184,000	$ 19,583,000
Trading securities										62,585,000	61,975,000																	55,034,000	61,922,000					7,551,000	53,000
Mark-to-market derivatives asset										66,659,000	62,230,000																	3,177,000	2,552,000					63,482,000	59,678,000
Collateral dependent impaired loans																																																																																										1,671,000	2,484,000	13,238,000	6,830,000	7,899,000	5,555,000	7,499,000	18,528,000	790,000	3,471,000	550,000	675,000							12,565,000	6,830,000	7,435,000	5,084,000	9,680,000	2,588,000	550,000	675,000					1,671,000	2,484,000	673,000	464,000	471,000	7,499,000	8,848,000	790,000	883,000
Collateral dependent impaired covered loans																																																																																											422,000																														422,000
Other real estate owned	117,501,000	107,530,000	129,340,000	162,541,000	178,164,000	178,183,000
Covered other real estate owned	82,834,000		98,550,000
Total assets at fair value										6,995,125,000	7,696,106,000																	76,925,000	84,883,000					6,851,849,000	7,591,640,000													66,351,000	19,583,000																																							83,652,000	111,360,000													48,550,000	66,837,000	3,455,000	6,558,000	58,415,000	81,755,000									37,865,000	56,898,000	25,237,000	29,605,000										10,685,000	9,939,000	3,455,000	6,558,000
Percent of total assets							1.00%	28.00%	33.00%																																																																															0.30%	0.50%
Prepayment rate (as a percent)																																																2.00%
Default rate of performing collateral (as a percent)																																																0.75%
Recovery Rate (as a percent)																																																15.00%
Recovery Rate lag time (in years)																																																2
Liabilities
Mark-to-market derivatives liabilities										61,400,000	52,881,000																	1,690,000	1,542,000					59,710,000	51,339,000
Other liabilities										417,000	263,000																							417,000	263,000
Total liabilities at fair value										61,817,000	53,144,000																	1,690,000	1,542,000					60,127,000	51,602,000																		61,800,000	53,100,000
Net (losses) gains recognized for assets measured at fair value on nonrecurring basis
Collateral dependent impaired loans:																																																											(367,000)	(606,000)	(1,572,000)	340,000	(1,937,000)	7,454,000	(540,000)	(47,000)	(1,122,000)	(189,000)	(281,000)	(3,417,000)	(6,753,000)	(1,199,000)	(115,000)	(546,000)	(62,000)	(510,000)	197,000	(107,000)	(4,317,000)
Total net losses recognized																																																							(6,541,000)	(20,542,000)	(22,973,000)	(25,558,000)																						(3,700,000)	(16,869,000)	(12,165,000)	(25,991,000)	(333,000)	(200,000)	(460,000)	(200,000)
Total net losses recognized on covered assets																																																																																$ 3,500,000	$ 14,600,000	$ 11,000,000	$ 22,800,000