Fair Value Measurement (Recurring and Nonrecurring Table) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012		Jun. 30, 2012
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	$ 3,299,392		$ 2,920,971		$ 3,216,365
Residential loans held for sale	22,855		23,683		19,018
Derivative Asset, Fair Value, Gross Asset	53,158		63,231		66,619
Total Assets, Fair Value Disclosure, Recurring	3,375,405		3,007,885		3,302,002
Derivative Liability, Fair Value, Gross Liability	62,217		77,968		85,803
True Up Liability	10,937		12,259		11,820
Total liabilities at fair value on a recurring basis	73,154	[1]	90,227	[1]	97,623
Nonrecurring Fair Value Measurements [Abstract]
Fair Value of Mortgage Servicing Rights	22,529	[2]	18,833	[2]	17,913
Impaired and Non Accrual Loans Fair Value Disclosure	52,606	[3]	54,491	[3]	73,110
Other Real Estate, Non Covered	16,825	[4]	7,540	[4]	10,839
Other Real Estate Covered by Loss Share	18,338	[5]	12,631	[5]	51,557
Nonrecurring Fair Value	110,298		93,495		153,419
Level 1 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	3,213		3,241		3,340
Residential loans held for sale	0		0		0
Derivative Asset, Fair Value, Gross Asset	0		0		0
Total Assets, Fair Value Disclosure, Recurring	3,213		3,241		3,340
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 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	3,083,667		2,868,069		3,164,929
Residential loans held for sale	22,855		23,683		19,018
Derivative Asset, Fair Value, Gross Asset	53,158		63,231		66,619
Total Assets, Fair Value Disclosure, Recurring	3,159,680		2,954,983		3,250,566
Derivative Liability, Fair Value, Gross Liability	62,217		77,968		85,803
True Up Liability	0		0		0
Total liabilities at fair value on a recurring basis	62,217	[1]	77,968	[1]	85,803
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 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	212,512		49,661		48,096
Residential loans held for sale	0		0		0
Derivative Asset, Fair Value, Gross Asset	0		0		0
Total Assets, Fair Value Disclosure, Recurring	212,512		49,661		48,096
Derivative Liability, Fair Value, Gross Liability	0		0		0
True Up Liability	10,937		12,259		11,820
Total liabilities at fair value on a recurring basis	10,937	[1]	12,259	[1]	11,820
Nonrecurring Fair Value Measurements [Abstract]
Fair Value of Mortgage Servicing Rights	22,529	[2]	18,833		17,913
Impaired and Non Accrual Loans Fair Value Disclosure	52,606		54,491		73,110
Other Real Estate, Non Covered	16,825	[4]	7,540	[4]	10,839
Other Real Estate Covered by Loss Share	18,338	[5]	12,631	[5]	51,557
Nonrecurring Fair Value	110,298		93,495		153,419
Equity Securities [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure			3,241		3,340
Equity Securities [Member] | Level 1 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure			3,241		3,340
Equity Securities [Member] | Level 2 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure			0		0
Equity Securities [Member] | Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure			0		0
Marketable equity securities [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	3,213
Marketable equity securities [Member] | Level 1 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	3,213
Marketable equity securities [Member] | Level 2 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	0
Marketable equity securities [Member] | Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	0
Equity Securities, Other [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	3,281
Equity Securities, Other [Member] | Level 1 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	0
Equity Securities, Other [Member] | Level 2 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	10
Equity Securities, Other [Member] | Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	3,271
US Government Agency Debentures [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure					35,297
US Government Agency Debentures [Member] | Level 1 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure					0
US Government Agency Debentures [Member] | Level 2 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure					35,297
US Government Agency Debentures [Member] | Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure					0
U.S. States and political subdivisions [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	277,934		268,204		265,124
U.S. States and political subdivisions [Member] | Level 1 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	0		0		0
U.S. States and political subdivisions [Member] | Level 2 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	277,934		268,204		265,124
U.S. States and political subdivisions [Member] | Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	0		0		0
Residential Mortgage Backed Securities Issued by US Government Sponsored Enterprises [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	1,075,928		1,107,063		1,382,813
Residential Mortgage Backed Securities Issued by US Government Sponsored Enterprises [Member] | Level 1 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	0		0		0
Residential Mortgage Backed Securities Issued by US Government Sponsored Enterprises [Member] | Level 2 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	1,075,928		1,107,063		1,382,813
Residential Mortgage Backed Securities Issued by US Government Sponsored Enterprises [Member] | Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	0		0		0
Commercial Mortgage Backed Securities Issued by US Government Sponsored Enterprises [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	56,497		52,036		38,428
Commercial Mortgage Backed Securities Issued by US Government Sponsored Enterprises [Member] | Level 1 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	0		0		0
Commercial Mortgage Backed Securities Issued by US Government Sponsored Enterprises [Member] | Level 2 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	56,497		52,036		38,428
Commercial Mortgage Backed Securities Issued by US Government Sponsored Enterprises [Member] | Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	0		0		0
Residential Collateralized Mortgage-Backed Securities Issued by US Government Sponsored Enterprises [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	1,566,728		1,329,421		1,277,378
Residential Collateralized Mortgage-Backed Securities Issued by US Government Sponsored Enterprises [Member] | Level 1 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	0		0		0
Residential Collateralized Mortgage-Backed Securities Issued by US Government Sponsored Enterprises [Member] | Level 2 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	1,566,728		1,329,421		1,277,378
Residential Collateralized Mortgage-Backed Securities Issued by US Government Sponsored Enterprises [Member] | Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	0		0		0
Residential Collateralized Mortgage-Backed Securities Issued by Non-US Government Agency [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	10		11		13
Residential Collateralized Mortgage-Backed Securities Issued by Non-US Government Agency [Member] | Level 1 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	0		0		0
Residential Collateralized Mortgage-Backed Securities Issued by Non-US Government Agency [Member] | Level 2 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	2		2		2
Residential Collateralized Mortgage-Backed Securities Issued by Non-US Government Agency [Member] | Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	8		9		11
Commercial Collateralized Mortgage Backed Securities Issued by US Government Sponsored Enterprises [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	106,568		111,343		68,545
Commercial Collateralized Mortgage Backed Securities Issued by US Government Sponsored Enterprises [Member] | Level 1 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	0		0		0
Commercial Collateralized Mortgage Backed Securities Issued by US Government Sponsored Enterprises [Member] | Level 2 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	106,568		111,343		68,545
Commercial Collateralized Mortgage Backed Securities Issued by US Government Sponsored Enterprises [Member] | Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	0		0		0
Corporate debt securities [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	51,138		49,652		145,427
Corporate debt securities [Member] | Level 1 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	0		0		0
Corporate debt securities [Member] | Level 2 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	0		0		97,342
Corporate debt securities [Member] | Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	51,138		49,652		48,085
Collateralized Loan Obligations [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	158,095
Collateralized Loan Obligations [Member] | Level 1 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	0
Collateralized Loan Obligations [Member] | Level 2 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	0
Collateralized Loan Obligations [Member] | Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale Securities, Fair Value Disclosure	158,095
Not Designated as Hedging Instrument [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	53,158	[6]	63,231	[6]	66,619	[6]
Derivative Liability, Fair Value, Gross Liability	47,898	[7]	58,888	[7]	62,574	[7]
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0	[6]	0	[6]	0	[6]
Derivative Liability, Fair Value, Gross Liability	14,319	[7]	19,080	[7]	23,229	[7]
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member] | Level 1 [Member]
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 [Member] | Designated as Hedging Instrument [Member] | Level 2 [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0		0		0
Derivative Liability, Fair Value, Gross Liability	14,319		19,080		23,229
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member] | Level 3 [Member]
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 [Member] | Not Designated as Hedging Instrument [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	47,804	[6]	58,769	[6]	61,319	[6]
Derivative Liability, Fair Value, Gross Liability	47,804	[7]	58,769	[7]	61,319	[7]
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member] | Level 1 [Member]
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 [Member] | Not Designated as Hedging Instrument [Member] | Level 2 [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	47,804		58,769		61,319
Derivative Liability, Fair Value, Gross Liability	47,804		58,769		61,319
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member] | Level 3 [Member]
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 [Member] | Not Designated as Hedging Instrument [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	779	[6]	4,400	[6]	5,248	[6]
Derivative Liability, Fair Value, Gross Liability	0	[7]	0	[7]	0	[7]
Mortgage Loan Commitments [Member] | Not Designated as Hedging Instrument [Member] | Level 1 [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0		0		0
Mortgage Loan Commitments [Member] | Not Designated as Hedging Instrument [Member] | Level 2 [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	779		4,400		5,248
Mortgage Loan Commitments [Member] | Not Designated as Hedging Instrument [Member] | Level 3 [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0		0		0
Forward Contracts [Member] | Not Designated as Hedging Instrument [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	4,458	[6]	0	[6]	0	[6]
Derivative Liability, Fair Value, Gross Liability	0	[7]	62	[7]	1,201	[7]
Forward Contracts [Member] | Not Designated as Hedging Instrument [Member] | Level 1 [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0		0		0
Derivative Liability, Fair Value, Gross Liability			0		0
Forward Contracts [Member] | Not Designated as Hedging Instrument [Member] | Level 2 [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	4,458		0		0
Derivative Liability, Fair Value, Gross Liability			62		1,201
Forward Contracts [Member] | Not Designated as Hedging Instrument [Member] | Level 3 [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0		0		0
Derivative Liability, Fair Value, Gross Liability			0		0
Foreign Exchange [Member] | Not Designated as Hedging Instrument [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	117	[6]	62	[6]	52	[6]
Derivative Liability, Fair Value, Gross Liability	94	[7]	57	[7]	54	[7]
Foreign Exchange [Member] | Not Designated as Hedging Instrument [Member] | Level 1 [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0		0		0
Derivative Liability, Fair Value, Gross Liability	0		0		0
Foreign Exchange [Member] | Not Designated as Hedging Instrument [Member] | Level 2 [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	117		62		52
Derivative Liability, Fair Value, Gross Liability	94		57		54
Foreign Exchange [Member] | Not Designated as Hedging Instrument [Member] | Level 3 [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0		0		0
Derivative Liability, Fair Value, Gross Liability	0		0		0
Other Contract [Member] | Not Designated as Hedging Instrument [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0	[6]	0	[6]	0	[6]
Derivative Liability, Fair Value, Gross Liability	0	[7]	0	[7]	0	[7]
Other Contract [Member] | Not Designated as Hedging Instrument [Member] | Level 1 [Member]
Recurring Fair Value Measurements
Derivative Liability, Fair Value, Gross Liability	0		0		0
Other Contract [Member] | Not Designated as Hedging Instrument [Member] | Level 2 [Member]
Recurring Fair Value Measurements
Derivative Liability, Fair Value, Gross Liability	0		0		0
Other Contract [Member] | Not Designated as Hedging Instrument [Member] | Level 3 [Member]
Recurring Fair Value Measurements
Derivative Liability, Fair Value, Gross Liability	$ 0		$ 0		$ 0

[1] (a) - There were no transfers between levels 1 and 2 of the fair value hierarchy during the three months ended June 30, 2013.

[2] (b) - MSRs with a recorded investment of $22.6 million were reduced by a specific valuation allowance totaling $0.5 million to a reported carrying value of $22.1 million resulting in recognition of $0.8 million in recoveries included in loans sales and servicing income in the three months ended June 30, 2013.

[3] (c) - Collateral dependent impaired loans with a recorded investment of $58.1 million were reduced by specific valuation allowance allocations totaling $5.5 million to a reported net carrying value of $52.6 million.

[4] (d) - Amounts do not include assets held at cost at June 30, 2013. During the three months ended June 30, 2013, the re-measurement of foreclosed assets at fair value subsequent to initial recognition resulted in losses of $0.3 million included in noninterest expense.

[5] (e) - Amounts do not include assets held at cost at June 30, 2013. During the three months ended June 30, 2013, the re-measurement of covered foreclosed assets at fair value subsequent to initial recognition resulted in losses $0.6 million included in noninterest expense.

[6] (a) Included in Other Assets on the Consolidated Balance Sheet

[7] (b) Included in Other Liabilities on the Consolidated Balance Sheet