Fair Value Measurements (Details) (USD $)	3 Months Ended																																														3 Months Ended						3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Mar. 31, 2013 Significant Other Observable Inputs Level 2 Maximum	Mar. 31, 2013 Significant Unobservable Inputs Level 3 Maximum	Dec. 31, 2012 Significant Unobservable Inputs Level 3 Maximum	Mar. 31, 2013 Measured on a Recurring Basis Fair Value	Dec. 31, 2012 Measured on a Recurring Basis Fair Value	Mar. 31, 2012 Measured on a Recurring Basis Fair Value	Dec. 31, 2011 Measured on a Recurring Basis Fair Value	Mar. 31, 2013 Measured on a Recurring Basis Fair Value U.S. Treasury	Dec. 31, 2012 Measured on a Recurring Basis Fair Value U.S. Treasury	Mar. 31, 2013 Measured on a Recurring Basis Fair Value Federal agency - Debt	Dec. 31, 2012 Measured on a Recurring Basis Fair Value Federal agency - Debt	Mar. 31, 2013 Measured on a Recurring Basis Fair Value Federal agency - MBS	Dec. 31, 2012 Measured on a Recurring Basis Fair Value Federal agency - MBS	Mar. 31, 2013 Measured on a Recurring Basis Fair Value CMOs - Federal agency	Dec. 31, 2012 Measured on a Recurring Basis Fair Value CMOs - Federal agency	Mar. 31, 2013 Measured on a Recurring Basis Fair Value CMOs - Non-agency	Dec. 31, 2012 Measured on a Recurring Basis Fair Value CMOs - Non-agency	Mar. 31, 2013 Measured on a Recurring Basis Fair Value State and municipal	Dec. 31, 2012 Measured on a Recurring Basis Fair Value State and municipal	Mar. 31, 2013 Measured on a Recurring Basis Fair Value Other debt securities	Dec. 31, 2012 Measured on a Recurring Basis Fair Value Other debt securities	Mar. 31, 2013 Measured on a Recurring Basis Fair Value Equity securities and mutual funds	Dec. 31, 2012 Measured on a Recurring Basis Fair Value Equity securities and mutual funds	Mar. 31, 2013 Measured on a Recurring Basis Quoted Prices in Active Markets Level 1	Dec. 31, 2012 Measured on a Recurring Basis Quoted Prices in Active Markets Level 1	Mar. 31, 2013 Measured on a Recurring Basis Quoted Prices in Active Markets Level 1 U.S. Treasury	Dec. 31, 2012 Measured on a Recurring Basis Quoted Prices in Active Markets Level 1 U.S. Treasury	Mar. 31, 2013 Measured on a Recurring Basis Quoted Prices in Active Markets Level 1 Equity securities and mutual funds	Dec. 31, 2012 Measured on a Recurring Basis Quoted Prices in Active Markets Level 1 Equity securities and mutual funds	Mar. 31, 2013 Measured on a Recurring Basis Significant Other Observable Inputs Level 2	Dec. 31, 2012 Measured on a Recurring Basis Significant Other Observable Inputs Level 2	Mar. 31, 2013 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 Federal agency - Debt	Dec. 31, 2012 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 Federal agency - Debt	Mar. 31, 2013 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 Federal agency - MBS	Dec. 31, 2012 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 Federal agency - MBS	Mar. 31, 2013 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 CMOs - Federal agency	Dec. 31, 2012 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 CMOs - Federal agency	Mar. 31, 2013 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 CMOs - Non-agency	Dec. 31, 2012 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 CMOs - Non-agency	Mar. 31, 2013 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 State and municipal	Dec. 31, 2012 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 State and municipal	Mar. 31, 2013 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 Other debt securities	Dec. 31, 2012 Measured on a Recurring Basis Significant Other Observable Inputs Level 2 Other debt securities	Mar. 31, 2013 Measured on a Recurring Basis Significant Unobservable Inputs Level 3	Dec. 31, 2012 Measured on a Recurring Basis Significant Unobservable Inputs Level 3	Mar. 31, 2013 Measured on a Recurring Basis Significant Unobservable Inputs Level 3 State and municipal	Dec. 31, 2012 Measured on a Recurring Basis Significant Unobservable Inputs Level 3 State and municipal	Mar. 31, 2013 Measured on a Recurring Basis Significant Unobservable Inputs Level 3 Other debt securities	Dec. 31, 2012 Measured on a Recurring Basis Significant Unobservable Inputs Level 3 Other debt securities	Mar. 31, 2012 Measured on a Nonrecurring Basis Commercial	Mar. 31, 2013 Measured on a Nonrecurring Basis Commercial real estate mortgages	Mar. 31, 2012 Measured on a Nonrecurring Basis Commercial real estate mortgages	Mar. 31, 2013 Measured on a Nonrecurring Basis Residential mortgage	Mar. 31, 2012 Measured on a Nonrecurring Basis Residential mortgage	Mar. 31, 2012 Measured on a Nonrecurring Basis Real estate construction	Mar. 31, 2013 Measured on a Nonrecurring Basis Home equity loans and lines of credit	Mar. 31, 2012 Measured on a Nonrecurring Basis Home equity loans and lines of credit	Mar. 31, 2013 Measured on a Nonrecurring Basis Installment loan	Mar. 31, 2012 Measured on a Nonrecurring Basis Installment loan	Mar. 31, 2013 Measured on a Nonrecurring Basis Other real estate owned	Mar. 31, 2012 Measured on a Nonrecurring Basis Other real estate owned	Mar. 31, 2013 Measured on a Nonrecurring Basis Private equity and alternative investments	Mar. 31, 2012 Measured on a Nonrecurring Basis Private equity and alternative investments	Mar. 31, 2013 Measured on a Nonrecurring Basis Fair Value	Dec. 31, 2012 Measured on a Nonrecurring Basis Fair Value	Mar. 31, 2013 Measured on a Nonrecurring Basis Fair Value Maximum	Dec. 31, 2012 Measured on a Nonrecurring Basis Fair Value Maximum	Dec. 31, 2012 Measured on a Nonrecurring Basis Fair Value Commercial	Mar. 31, 2013 Measured on a Nonrecurring Basis Fair Value Commercial real estate mortgages	Dec. 31, 2012 Measured on a Nonrecurring Basis Fair Value Commercial real estate mortgages	Dec. 31, 2012 Measured on a Nonrecurring Basis Fair Value Residential mortgage	Dec. 31, 2012 Measured on a Nonrecurring Basis Fair Value Real estate construction	Dec. 31, 2012 Measured on a Nonrecurring Basis Fair Value Home equity loans and lines of credit	Dec. 31, 2012 Measured on a Nonrecurring Basis Fair Value Installment loan	Mar. 31, 2013 Measured on a Nonrecurring Basis Fair Value Other real estate owned	Dec. 31, 2012 Measured on a Nonrecurring Basis Fair Value Other real estate owned	Mar. 31, 2013 Measured on a Nonrecurring Basis Fair Value Private equity and alternative investments	Dec. 31, 2012 Measured on a Nonrecurring Basis Fair Value Private equity and alternative investments	Mar. 31, 2013 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2	Dec. 31, 2012 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2	Dec. 31, 2012 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2 Commercial real estate mortgages	Dec. 31, 2012 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2 Installment loan	Mar. 31, 2013 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2 Other real estate owned	Dec. 31, 2012 Measured on a Nonrecurring Basis Significant Other Observable Inputs Level 2 Other real estate owned	Mar. 31, 2013 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3	Dec. 31, 2012 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3	Dec. 31, 2012 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Commercial	Mar. 31, 2013 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Commercial real estate mortgages	Dec. 31, 2012 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Commercial real estate mortgages	Dec. 31, 2012 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Residential mortgage	Dec. 31, 2012 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Real estate construction	Dec. 31, 2012 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Home equity loans and lines of credit	Mar. 31, 2013 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Other real estate owned	Dec. 31, 2012 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Other real estate owned	Mar. 31, 2013 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Private equity and alternative investments	Dec. 31, 2012 Measured on a Nonrecurring Basis Significant Unobservable Inputs Level 3 Private equity and alternative investments
Fair Value Measurements
Fair value of assets transfers from Level 1 to Level 2	$ 0
Fair value of assets transfers from Level 2 to Level 1	0
Fair value of liabilities transfers from Level 1 to Level 2	0
Fair value of liabilities transfers from Level 2 to Level 1	0
Assets
Securities available-for-sale											30,370,000	20,397,000	1,114,603,000	2,349,202,000	645,480,000	693,032,000	5,139,231,000	5,318,253,000	50,776,000	61,513,000	445,170,000	454,474,000	309,392,000	307,417,000	3,029,000	1,701,000			30,370,000	20,397,000	3,029,000	1,701,000			1,114,603,000	2,349,202,000	645,480,000	693,032,000	5,139,231,000	5,318,253,000	50,776,000	61,513,000	398,960,000	407,429,000	294,117,000	289,275,000			46,210,000	47,045,000	15,275,000	18,142,000
Trading securities							53,526,000	115,059,000																			50,783,000	113,010,000					2,743,000	2,049,000
Mark-to-market derivatives asset	59,055,000																										382,000						58,673,000
Collateral dependent impaired loans																																																																							2,655,000	7,300,000	10,963,000	1,811,000	7,918,000	780,000	550,000							3,950,000	550,000					2,655,000	7,300,000	7,013,000	1,811,000	7,918,000	780,000
Total assets at fair value							7,850,632,000	9,388,544,000																			84,564,000	135,326,000					7,704,583,000	9,188,031,000													61,485,000	65,187,000																			21,323,000	75,251,000										13,337,000	44,396,000	686,000	6,178,000	11,218,000	39,124,000			11,218,000	34,624,000	10,105,000	36,127,000							2,119,000	9,772,000	686,000	6,178,000
Percent of total assets				1.00%	1.00%	1.00%	29.00%	33.00%																																																													1.00%	1.00%
Fair value of senior notes																																															15,300,000
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																																															2 years
Assets purchases measured on fair value of Level 3 on a recurring basis	0	0
Assets sales measured on fair value of Level 3 on a recurring basis	0	0
Fair value of assets transfers out of Level 3	0	0
Liabilities
Mark-to-market derivatives liabilities							57,862,000	64,432,000																									57,862,000	64,432,000
Contingent consideration liability							48,273,000	47,724,000	(8,719,000)	(8,102,000)																																					48,273,000	47,724,000
FDIC clawback liability							10,765,000	9,970,000																																							10,765,000	9,970,000
Other liabilities							344,000	368,000																									344,000	368,000
Total liabilities at fair value							117,244,000	122,494,000																									58,206,000	64,800,000													59,038,000	57,694,000
Redeemable noncontrolling interest	41,113,000		41,112,000				41,113,000	41,112,000																																							41,113,000	41,112,000
Net (losses) gains recognized for assets measured at fair value on nonrecurring basis
Collateral dependent impaired loans:																																																					(368,000)	145,000	(365,000)	9,000	(582,000)	(6,472,000)	116,000	54,000	(138,000)	(107,000)
Total net losses recognized	(3,120,000)	(16,432,000)																																																													(2,853,000)	(8,465,000)	(399,000)	(127,000)
Total net losses recognized on covered assets																																																															$ 2,800,000	$ 7,600,000