Fair Value Measurement (Recurring and Nonrecurring Table) (Details) (USD $)	Jun. 30, 2014		Dec. 31, 2013		Jun. 30, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral Dependant Impaired and Non Accrual Loans Carrying Amount	$ 56,000,000		$ 47,900,000		$ 52,600,000
Recurring Fair Value Measurements
Available-for-sale	3,478,420,000		3,273,174,000		3,299,392,000
Residential loans held for sale	21,632,000		11,622,000		22,855,000
Loans held for sale	21,632,000		11,622,000		22,855,000
Derivative Asset, Fair Value, Gross Asset	50,550,000		47,902,000		53,158,000
Total Assets, Fair Value Disclosure, Recurring	3,550,602,000		3,332,698,000		3,375,405,000
Derivative Liability, Fair Value, Gross Liability	57,544,000		58,201,000		62,217,000
True Up Liability	12,581,000		11,463,000		10,937,000
Total liabilities at fair value on a recurring basis	70,125,000	[1]	69,664,000	[1]	73,154,000
Nonrecurring Fair Value Measurements [Abstract]
Fair Value of Mortgage Servicing Rights	21,987,000	[2]	23,041,000	[2]	22,529,000
Impaired and Non Accrual Loans Fair Value Disclosure	56,006,000	[3]	47,870,000	[3]	52,606,000
Other Real Estate, Non Covered	17,052,000	[4]	10,018,000	[4]	16,825,000
Other Real Estate Covered by Loss Share	22,782,000	[5]	8,754,000	[5]	18,338,000
Nonrecurring Fair Value	117,827,000		89,683,000		110,298,000
Level 1
Recurring Fair Value Measurements
Available-for-sale	2,935,000		3,036,000		3,213,000
Residential loans held for sale	0		0		0
Derivative Asset, Fair Value, Gross Asset	0		0		0
Total Assets, Fair Value Disclosure, Recurring	2,935,000		3,036,000		3,213,000
Derivative Liability, Fair Value, Gross Liability	0		0		0
True Up Liability	0		0		0
Total liabilities at fair value on a recurring basis	0	[1]	0	[1]	0
Nonrecurring Fair Value Measurements [Abstract]
Fair Value of Mortgage Servicing Rights	0	[2]	0	[2]	0
Impaired and Non Accrual Loans Fair Value Disclosure	0	[3]	0	[3]	0
Other Real Estate, Non Covered	0	[4]	0	[4]	0
Other Real Estate Covered by Loss Share	0	[5]	0	[5]	0
Nonrecurring Fair Value	0		0		0
Level 2
Recurring Fair Value Measurements
Available-for-sale	3,124,752,000		2,922,527,000		3,083,667,000
Residential loans held for sale			11,622,000		22,855,000
Loans held for sale	21,632,000
Derivative Asset, Fair Value, Gross Asset	50,550,000		47,902,000		53,158,000
Total Assets, Fair Value Disclosure, Recurring	3,196,934,000		2,982,051,000		3,159,680,000
Derivative Liability, Fair Value, Gross Liability	57,544,000		58,201,000		62,217,000
True Up Liability	0		0		0
Total liabilities at fair value on a recurring basis	57,544,000	[1]	58,201,000	[1]	62,217,000
Nonrecurring Fair Value Measurements [Abstract]
Fair Value of Mortgage Servicing Rights	0	[2]	0	[2]	0
Impaired and Non Accrual Loans Fair Value Disclosure	0	[3]	0	[3]	0
Other Real Estate, Non Covered	0	[4]	0	[4]	0
Other Real Estate Covered by Loss Share	0	[5]	0	[5]	0
Nonrecurring Fair Value	0		0		0
Level 3
Recurring Fair Value Measurements
Available-for-sale	350,733,000		347,611,000		212,512,000
Residential loans held for sale	0		0		0
Derivative Asset, Fair Value, Gross Asset	0		0		0
Total Assets, Fair Value Disclosure, Recurring	350,733,000		347,611,000		212,512,000
Derivative Liability, Fair Value, Gross Liability	0		0		0
True Up Liability	12,581,000		11,463,000		10,937,000
Total liabilities at fair value on a recurring basis	12,581,000	[1]	11,463,000	[1]	10,937,000
Nonrecurring Fair Value Measurements [Abstract]
Fair Value of Mortgage Servicing Rights	21,987,000	[2]	23,041,000		22,529,000
Impaired and Non Accrual Loans Fair Value Disclosure	56,006,000		47,870,000		52,606,000
Other Real Estate, Non Covered	17,052,000	[4]	10,018,000	[4]	16,825,000
Other Real Estate Covered by Loss Share	22,782,000	[5]	8,754,000	[5]	18,338,000
Nonrecurring Fair Value	117,827,000		89,683,000		110,298,000
Equity Securities
Recurring Fair Value Measurements
Available-for-sale	2,935,000		3,036,000		3,213,000
Equity Securities | Level 1
Recurring Fair Value Measurements
Available-for-sale	2,935,000		3,036,000		3,213,000
Equity Securities | Level 2
Recurring Fair Value Measurements
Available-for-sale	0		0		0
Equity Securities | Level 3
Recurring Fair Value Measurements
Available-for-sale	0		0		0
Non-marketable Equity Securities [Member]
Recurring Fair Value Measurements
Available-for-sale	3,281,000		3,281,000		3,281,000
Non-marketable Equity Securities [Member] | Level 1
Recurring Fair Value Measurements
Available-for-sale	0		0
Non-marketable Equity Securities [Member] | Level 2
Recurring Fair Value Measurements
Available-for-sale	10,000		10,000		10,000
Non-marketable Equity Securities [Member] | Level 3
Recurring Fair Value Measurements
Available-for-sale	3,271,000		3,271,000		3,271,000
U.S. States and political subdivisions debt securities
Recurring Fair Value Measurements
Available-for-sale	240,805,000		262,367,000		277,934,000
U.S. States and political subdivisions debt securities | Level 1
Recurring Fair Value Measurements
Available-for-sale	0		0		0
U.S. States and political subdivisions debt securities | Level 2
Recurring Fair Value Measurements
Available-for-sale	240,805,000		262,367,000		277,934,000
U.S. States and political subdivisions debt securities | Level 3
Recurring Fair Value Measurements
Available-for-sale	0		0		0
Residential Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Recurring Fair Value Measurements
Available-for-sale	1,018,174,000		969,922,000		1,075,928,000
Residential Mortgage Backed Securities Issued by US Government Sponsored Enterprises | Level 1
Recurring Fair Value Measurements
Available-for-sale	0		0		0
Residential Mortgage Backed Securities Issued by US Government Sponsored Enterprises | Level 2
Recurring Fair Value Measurements
Available-for-sale	1,018,174,000		969,922,000		1,075,928,000
Residential Mortgage Backed Securities Issued by US Government Sponsored Enterprises | Level 3
Recurring Fair Value Measurements
Available-for-sale	0		0		0
Commercial Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Recurring Fair Value Measurements
Available-for-sale	85,698,000		69,567,000		56,497,000
Commercial Mortgage Backed Securities Issued by US Government Sponsored Enterprises | Level 1
Recurring Fair Value Measurements
Available-for-sale	0		0		0
Commercial Mortgage Backed Securities Issued by US Government Sponsored Enterprises | Level 2
Recurring Fair Value Measurements
Available-for-sale	85,698,000		69,567,000		56,497,000
Commercial Mortgage Backed Securities Issued by US Government Sponsored Enterprises | Level 3
Recurring Fair Value Measurements
Available-for-sale	0		0		0
Residential Collateralized Mortgage-Backed Securities Issued by US Government Sponsored Enterprises
Recurring Fair Value Measurements
Available-for-sale	1,598,031,000		1,518,393,000		1,566,728,000
Residential Collateralized Mortgage-Backed Securities Issued by US Government Sponsored Enterprises | Level 1
Recurring Fair Value Measurements
Available-for-sale	0		0		0
Residential Collateralized Mortgage-Backed Securities Issued by US Government Sponsored Enterprises | Level 2
Recurring Fair Value Measurements
Available-for-sale	1,598,031,000		1,518,393,000		1,566,728,000
Residential Collateralized Mortgage-Backed Securities Issued by US Government Sponsored Enterprises | Level 3
Recurring Fair Value Measurements
Available-for-sale	0		0		0
Residential Collateralized Mortgage-Backed Securities Issued by Non-US Government Agency
Recurring Fair Value Measurements
Available-for-sale	8,000		9,000		10,000
Residential Collateralized Mortgage-Backed Securities Issued by Non-US Government Agency | Level 1
Recurring Fair Value Measurements
Available-for-sale	0		0		0
Residential Collateralized Mortgage-Backed Securities Issued by Non-US Government Agency | Level 2
Recurring Fair Value Measurements
Available-for-sale	1,000		0		2,000
Residential Collateralized Mortgage-Backed Securities Issued by Non-US Government Agency | Level 3
Recurring Fair Value Measurements
Available-for-sale	7,000		9,000		8,000
Commercial Collateralized Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Recurring Fair Value Measurements
Available-for-sale	182,033,000		102,268,000		106,568,000
Commercial Collateralized Mortgage Backed Securities Issued by US Government Sponsored Enterprises | Level 1
Recurring Fair Value Measurements
Available-for-sale	0		0		0
Commercial Collateralized Mortgage Backed Securities Issued by US Government Sponsored Enterprises | Level 2
Recurring Fair Value Measurements
Available-for-sale	182,033,000		102,268,000		106,568,000
Commercial Collateralized Mortgage Backed Securities Issued by US Government Sponsored Enterprises | Level 3
Recurring Fair Value Measurements
Available-for-sale	0		0		0
Corporate debt securities
Recurring Fair Value Measurements
Available-for-sale	53,490,000		50,644,000		51,138,000
Corporate debt securities | Level 1
Recurring Fair Value Measurements
Available-for-sale	0		0		0
Corporate debt securities | Level 2
Recurring Fair Value Measurements
Available-for-sale	0		0		0
Corporate debt securities | Level 3
Recurring Fair Value Measurements
Available-for-sale	53,490,000		50,644,000		51,138,000
Collateralized Loan Obligations
Recurring Fair Value Measurements
Available-for-sale	293,965,000		293,687,000		158,095,000
Collateralized Loan Obligations | Level 1
Recurring Fair Value Measurements
Available-for-sale	0		0		0
Collateralized Loan Obligations | Level 2
Recurring Fair Value Measurements
Available-for-sale	0		0		0
Collateralized Loan Obligations | Level 3
Recurring Fair Value Measurements
Available-for-sale	293,965,000		293,687,000		158,095,000
Not Designated as Hedging Instrument
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	50,550,000	[6]	47,902,000	[6]	53,158,000	[6]
Derivative Liability, Fair Value, Gross Liability	48,555,000		46,627,000		47,898,000
Credit Risk Contract | Not Designated as Hedging Instrument
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0	[6]	0	[6]	0	[6]
Derivative Liability, Fair Value, Gross Liability	10,000		0		0
Interest Rate Swap | Designated as Hedging Instrument
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0	[6]	0	[6]	0	[6]
Derivative Liability, Fair Value, Gross Liability	8,989,000		11,574,000		14,319,000
Interest Rate Swap | Designated as Hedging Instrument | Level 1
Recurring Fair Value Measurements
Derivative Liability, Fair Value, Gross Liability	0		0		0
Interest Rate Swap | Designated as Hedging Instrument | Level 2
Recurring Fair Value Measurements
Derivative Liability, Fair Value, Gross Liability			11,574,000		14,319,000
Interest Rate Swap | Designated as Hedging Instrument | Level 3
Recurring Fair Value Measurements
Derivative Liability, Fair Value, Gross Liability	0		0		0
Interest Rate Swap | Not Designated as Hedging Instrument
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	47,952,000	[6]	46,577,000	[6]	47,804,000	[6]
Derivative Liability, Fair Value, Gross Liability	47,952,000		46,577,000		47,804,000
Interest Rate Swap | Not Designated as Hedging Instrument | Level 1
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0		0		0
Derivative Liability, Fair Value, Gross Liability	0		0		0
Interest Rate Swap | Not Designated as Hedging Instrument | Level 2
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset			46,577,000		47,804,000
Derivative Liability, Fair Value, Gross Liability			46,577,000		47,804,000
Interest Rate Swap | Not Designated as Hedging Instrument | Level 3
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0		0		0
Derivative Liability, Fair Value, Gross Liability	0		0		0
Mortgage Loan Commitments | Not Designated as Hedging Instrument
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	2,491,000	[6]	891,000	[6]	779,000	[6]
Derivative Liability, Fair Value, Gross Liability	0		0		0
Mortgage Loan Commitments | Not Designated as Hedging Instrument | Level 1
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0		0		0
Mortgage Loan Commitments | Not Designated as Hedging Instrument | Level 2
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset			891,000		779,000
Mortgage Loan Commitments | Not Designated as Hedging Instrument | Level 3
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0		0		0
Forward sales contracts | Not Designated as Hedging Instrument
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0	[6]	384,000	[6]	4,458,000	[6]
Derivative Liability, Fair Value, Gross Liability	545,000		0		0
Forward sales contracts | Not Designated as Hedging Instrument | Level 1
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0		0		0
Derivative Liability, Fair Value, Gross Liability	0
Forward sales contracts | Not Designated as Hedging Instrument | Level 2
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset			384,000		4,458,000
Forward sales contracts | Not Designated as Hedging Instrument | Level 3
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0		0		0
Derivative Liability, Fair Value, Gross Liability	0
Foreign Exchange | Not Designated as Hedging Instrument
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	107,000	[6]	50,000	[6]	117,000	[6]
Derivative Liability, Fair Value, Gross Liability	48,000		50,000		94,000
Foreign Exchange | Not Designated as Hedging Instrument | Level 1
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0		0		0
Derivative Liability, Fair Value, Gross Liability	0		0		0
Foreign Exchange | Not Designated as Hedging Instrument | Level 2
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset			50,000		117,000
Derivative Liability, Fair Value, Gross Liability			50,000		94,000
Foreign Exchange | Not Designated as Hedging Instrument | Level 3
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0		0		0
Derivative Liability, Fair Value, Gross Liability	0		0		0
Other Contract | Not Designated as Hedging Instrument
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0	[6]	0	[6]	0	[6]
Derivative Liability, Fair Value, Gross Liability	0		0		0
Other Contract | Not Designated as Hedging Instrument | Level 1
Recurring Fair Value Measurements
Derivative Liability, Fair Value, Gross Liability	0
Other Contract | Not Designated as Hedging Instrument | Level 3
Recurring Fair Value Measurements
Derivative Liability, Fair Value, Gross Liability	$ 0

[1] (a) - There were no transfers between levels 1 and 2 of the fair value hierarchy during the three months ended June 30, 2014.

[2] (b) - MSRs with a recorded investment of $22.2 million were reduced by a specific valuation allowance totaling $0.6 million to a reported carrying value of $21.6 million resulting in recognition of $0.1 million in expense included in loans sales and servicing income in the three months ended June 30, 2014.

[3] (c) - Collateral dependent impaired loans with a recorded investment of $62.2 million were reduced by specific valuation allowance allocations totaling $6.2 million to a reported net carrying value of $56.0 million.

[4] (d) - Amounts do not include assets held at cost at June 30, 2014. During the three months ended June 30, 2014, the re-measurement of foreclosed assets at fair value subsequent to initial recognition resulted in losses of $0.7 million included in noninterest expense.

[5] (e) - Amounts do not include assets held at cost at June 30, 2014. During the three months ended June 30, 2014, the re-measurement of covered foreclosed assets at fair value subsequent to initial recognition resulted in losses $0.7 million included in noninterest expense.

[6] (a) Included in "Other assets" on the Consolidated Balance Sheets(b) Included in "Other liabilities" on the Consolidated Balance Sheets