Fair Value Measurements (Details) (USD $)																																														3 Months Ended						3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011	Dec. 31, 2010	Mar. 31, 2012 Significant Unobservable Inputs Level 3	Mar. 31, 2012 Measured on a Recurring Basis	Dec. 31, 2011 Measured on a Recurring Basis	Mar. 31, 2012 Measured on a Recurring Basis Fair Value	Dec. 31, 2011 Measured on a Recurring Basis Fair Value	Mar. 31, 2012 Measured on a Recurring Basis Fair Value U.S. Treasury	Dec. 31, 2011 Measured on a Recurring Basis Fair Value U.S. Treasury	Mar. 31, 2012 Measured on a Recurring Basis Fair Value Federal agency - Debt	Dec. 31, 2011 Measured on a Recurring Basis Fair Value Federal agency - Debt	Mar. 31, 2012 Measured on a Recurring Basis Fair Value Federal agency - MBS	Dec. 31, 2011 Measured on a Recurring Basis Fair Value Federal agency - MBS	Mar. 31, 2012 Measured on a Recurring Basis Fair Value CMOs - Federal agency	Dec. 31, 2011 Measured on a Recurring Basis Fair Value CMOs - Federal agency	Mar. 31, 2012 Measured on a Recurring Basis Fair Value CMOs - Non-agency	Dec. 31, 2011 Measured on a Recurring Basis Fair Value CMOs - Non-agency	Mar. 31, 2012 Measured on a Recurring Basis Fair Value State and municipal	Dec. 31, 2011 Measured on a Recurring Basis Fair Value State and municipal	Mar. 31, 2012 Measured on a Recurring Basis Fair Value Other debt securities	Dec. 31, 2011 Measured on a Recurring Basis Fair Value Other debt securities	Mar. 31, 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	Mar. 31, 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	Mar. 31, 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	Mar. 31, 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	Mar. 31, 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	Mar. 31, 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	Mar. 31, 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	Mar. 31, 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	Mar. 31, 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	Mar. 31, 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	Mar. 31, 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	Mar. 31, 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	Mar. 31, 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	Mar. 31, 2012 Measured on a Recurring Basis Level 1 or Level 2	Dec. 31, 2011 Measured on a Recurring Basis Level 1 or Level 2	Mar. 31, 2012 Measured on a Nonrecurring Basis	Mar. 31, 2011 Measured on a Nonrecurring Basis	Mar. 31, 2012 Measured on a Nonrecurring Basis Commercial	Mar. 31, 2011 Measured on a Nonrecurring Basis Commercial	Mar. 31, 2012 Measured on a Nonrecurring Basis Commercial real estate mortgages	Mar. 31, 2011 Measured on a Nonrecurring Basis Commercial real estate mortgages	Mar. 31, 2012 Measured on a Nonrecurring Basis Residential mortgage	Mar. 31, 2011 Measured on a Nonrecurring Basis Residential mortgage	Mar. 31, 2012 Measured on a Nonrecurring Basis Real estate construction	Mar. 31, 2011 Measured on a Nonrecurring Basis Real estate construction	Mar. 31, 2012 Measured on a Nonrecurring Basis Equity lines of credit	Mar. 31, 2011 Measured on a Nonrecurring Basis Equity lines of credit	Mar. 31, 2012 Measured on a Nonrecurring Basis Installment loan	Mar. 31, 2011 Measured on a Nonrecurring Basis Installment loan	Mar. 31, 2012 Measured on a Nonrecurring Basis Other real estate owned	Mar. 31, 2011 Measured on a Nonrecurring Basis Other real estate owned	Mar. 31, 2012 Measured on a Nonrecurring Basis Private equity and alternative investments	Mar. 31, 2012 Measured on a Nonrecurring Basis Fair Value	Dec. 31, 2011 Measured on a Nonrecurring Basis Fair Value	Mar. 31, 2012 Measured on a Nonrecurring Basis Fair Value Commercial	Dec. 31, 2011 Measured on a Nonrecurring Basis Fair Value Commercial	Mar. 31, 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	Mar. 31, 2012 Measured on a Nonrecurring Basis Fair Value Residential mortgage	Dec. 31, 2011 Measured on a Nonrecurring Basis Fair Value Residential mortgage	Mar. 31, 2012 Measured on a Nonrecurring Basis Fair Value Real estate construction	Dec. 31, 2011 Measured on a Nonrecurring Basis Fair Value Real estate construction	Mar. 31, 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	Mar. 31, 2012 Measured on a Nonrecurring Basis Fair Value Installment loan	Dec. 31, 2011 Measured on a Nonrecurring Basis Fair Value Installment loan	Mar. 31, 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	Mar. 31, 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	Mar. 31, 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	Mar. 31, 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	Mar. 31, 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	Mar. 31, 2012 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 Real estate construction	Dec. 31, 2011 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2 Equity lines of credit	Mar. 31, 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	Mar. 31, 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	Mar. 31, 2012 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3	Dec. 31, 2011 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3	Mar. 31, 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	Mar. 31, 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	Mar. 31, 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	Mar. 31, 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	Mar. 31, 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	Mar. 31, 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										$ 19,202,000	$ 19,182,000	$ 1,051,348,000	$ 1,973,862,000	$ 720,590,000	$ 681,044,000	$ 4,400,318,000	$ 4,326,907,000	$ 68,587,000	$ 69,001,000	$ 395,723,000	$ 401,604,000	$ 181,792,000	$ 99,074,000	$ 1,150,000	$ 1,227,000			$ 19,202,000	$ 19,182,000	$ 1,150,000	$ 1,227,000			$ 1,051,348,000	$ 1,973,862,000	$ 720,590,000	$ 681,044,000	$ 4,400,318,000	$ 4,326,907,000	$ 68,587,000	$ 69,001,000	$ 395,723,000	$ 401,604,000	$ 162,783,000	$ 79,491,000			$ 19,009,000	$ 19,583,000
Trading securities								82,589,000	61,975,000																	80,527,000	61,922,000					2,062,000	53,000
Mark-to-market derivatives asset								57,891,000	62,230,000																	3,239,000	2,552,000					54,652,000	59,678,000
Collateral dependent impaired loans																																																																							1,878,000	2,484,000	3,170,000	6,830,000	5,988,000	5,555,000	14,300,000	18,528,000	904,000	3,471,000	550,000	675,000							3,170,000	6,830,000	5,525,000	5,084,000	7,500,000	9,680,000	2,588,000	550,000	675,000					1,878,000	2,484,000	463,000	471,000	6,800,000	8,848,000	904,000	883,000
Collateral dependent impaired covered loans																																																																								422,000																															422,000
Other real estate owned	107,530,000	129,340,000	178,164,000	178,183,000
Covered other real estate owned	78,456,000	98,550,000
Total assets at fair value								6,979,190,000	7,696,106,000																	104,118,000	84,883,000					6,856,063,000	7,591,640,000													19,009,000	19,583,000																						54,395,000	111,360,000													27,347,000	66,837,000	258,000	6,558,000	40,014,000	81,755,000										23,269,000	56,898,000	14,381,000	29,605,000									4,078,000	9,939,000	258,000	6,558,000
Percent of total assets					1.00%	29.00%	33.00%																																																														0.20%	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								49,384,000	52,881,000																	1,574,000	1,542,000					47,810,000	51,339,000
Other liabilities								290,000	263,000																							290,000	263,000
Total liabilities at fair value								49,674,000	53,144,000																	1,574,000	1,542,000					48,100,000	51,602,000																	49,700,000	53,100,000
Net (losses) gains recognized for assets measured at fair value on nonrecurring basis
Collateral dependent impaired loans:																																																						(368,000)	(606,000)	(365,000)	7,114,000	(582,000)	(142,000)	(6,472,000)	2,217,000	54,000	36,000	(107,000)	(4,514,000)
Total net losses recognized																																																				(16,432,000)	(5,017,000)													(8,465,000)	(9,122,000)	(127,000)
Total net losses recognized on covered assets																																																																		$ (7,600,000)	$ (8,200,000)