Loans and Allowance for Loan Losses (Loan Portfolio Credit Exposure) (Details) (USD $)	Jun. 30, 2013		Dec. 31, 2012		Jun. 30, 2012
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 19,632,050,000	[1]	$ 19,562,063,000	[2]	$ 19,693,445,000
Nonaccrual substandard loans	437,300,000		518,100,000
Deferred fees and costs, net	23,800,000		20,400,000		13,300,000
Home Equity Lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,507,738,000		1,542,397,000
Consumer Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,451,212,000		1,411,561,000
Credit Cards [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	251,788,000		263,561,000
Small Business [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	568,881,000		516,349,000
Other Retail Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	278,603,000		277,229,000
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	9,231,499,000		9,101,514,000
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,342,329,000		6,449,452,000
Investment Properties [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,392,523,000		4,376,118,000
1-4 Family Properties [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,197,487,000		1,279,105,000
Land Acquisition [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	752,319,000		794,229,000
Retail [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,058,222,000		4,011,097,000
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	17,495,214,000		16,969,188,000
Pass [Member] | Home Equity Lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,477,367,000		1,511,729,000
Pass [Member] | Consumer Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,415,981,000		1,372,957,000
Pass [Member] | Credit Cards [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	249,969,000		260,194,000
Pass [Member] | Small Business [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	559,000,000		504,503,000
Pass [Member] | Other Retail Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	275,348,000		271,619,000
Pass [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,343,695,000		8,069,049,000
Pass [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,173,854,000		4,979,137,000
Pass [Member] | Investment Properties [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,866,906,000		3,659,102,000
Pass [Member] | 1-4 Family Properties [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	881,870,000		903,213,000
Pass [Member] | Land Acquisition [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	425,078,000		416,822,000
Pass [Member] | Retail [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,977,665,000		3,921,002,000
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,043,928,000		1,376,956,000
Special Mention [Member] | Home Equity Lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0		0
Special Mention [Member] | Consumer Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0		0
Special Mention [Member] | Credit Cards [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0		0
Special Mention [Member] | Small Business [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0		0
Special Mention [Member] | Other Retail Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0		0
Special Mention [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	443,765,000		572,591,000
Special Mention [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	600,163,000		804,365,000
Special Mention [Member] | Investment Properties [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	296,474,000		463,532,000
Special Mention [Member] | 1-4 Family Properties [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	173,155,000		197,148,000
Special Mention [Member] | Land Acquisition [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	130,534,000		143,685,000
Special Mention [Member] | Retail [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0		0
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,046,742,000	[3]	1,190,707,000	[3]
Substandard [Member] | Home Equity Lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	26,746,000	[3]	29,094,000	[3]
Substandard [Member] | Consumer Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	33,431,000	[3]	38,023,000	[3]
Substandard [Member] | Credit Cards [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	656,000	[3]	1,776,000	[3]
Substandard [Member] | Small Business [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	9,011,000	[3]	10,563,000	[3]
Substandard [Member] | Other Retail Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,157,000	[3]	5,379,000	[3]
Substandard [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	424,333,000	[3]	447,955,000	[3]
Substandard [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	549,408,000	[3]	657,917,000	[3]
Substandard [Member] | Investment Properties [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	226,339,000	[3]	253,484,000	[3]
Substandard [Member] | 1-4 Family Properties [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	129,788,000	[3]	176,672,000	[3]
Substandard [Member] | Land Acquisition [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	193,281,000	[3]	227,761,000	[3]
Substandard [Member] | Retail [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	73,001,000	[3]	84,835,000	[3]
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	38,515,000	[4]	19,733,000	[4]
Doubtful [Member] | Home Equity Lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	[4]	0	[4]
Doubtful [Member] | Consumer Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	[4]	0	[4]
Doubtful [Member] | Credit Cards [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	[4]	0	[4]
Doubtful [Member] | Small Business [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	[4]	0	[4]
Doubtful [Member] | Other Retail Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	[4]	0	[4]
Doubtful [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	19,611,000	[4]	11,819,000	[4]
Doubtful [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	18,904,000	[4]	7,914,000	[4]
Doubtful [Member] | Investment Properties [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,804,000	[4]	0	[4]
Doubtful [Member] | 1-4 Family Properties [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	12,674,000	[4]	1,953,000	[4]
Doubtful [Member] | Land Acquisition [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,426,000	[4]	5,961,000	[4]
Doubtful [Member] | Retail [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	[4]	0	[4]
Loss [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,651,000		5,479,000
Loss [Member] | Home Equity Lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,625,000	[4],[5]	1,574,000	[4],[5]
Loss [Member] | Consumer Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,800,000	[4],[5]	581,000	[4],[5]
Loss [Member] | Credit Cards [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,163,000	[5]	1,591,000	[5]
Loss [Member] | Small Business [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	870,000	[4],[5]	1,283,000	[4],[5]
Loss [Member] | Other Retail Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	98,000	[4],[5]	231,000	[4],[5]
Loss [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	95,000	[4],[6]	100,000
Loss [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0		119,000
Loss [Member] | Investment Properties [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0		0
Loss [Member] | 1-4 Family Properties [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0		119,000	[4],[6]
Loss [Member] | Land Acquisition [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0		0
Loss [Member] | Retail [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 7,556,000		$ 5,260,000

[1] Total before net deferred fees and costs of $23.8 million

[2] Total before net deferred fees and costs of $20.4 million

[3] Includes $437.3 million and $518.1 million of non-accrual Substandard loans at June 30, 2013 and December 31, 2012, respectively.

[4] The loans within these risk grades are on non-accrual status.

[5] Represent amounts that were 120 days past due. These credits are downgraded to the Loss category with an allowance for loan losses equal to the full loan amount and are charged off in the subsequent quarter.

[6] Amount was fully reserved and was charged-off in the subsequent quarter.