Loans and Credit Quality Loans and Credit Quality (Details 5) (NonCovered [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Schedule Of Non Accrual and Performing Restructured Impaired Financing Receivables [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 139,334	$ 83,621
Impaired Financing Receivable Performing Restructured Loans	35,975	35,244
Impaired Financing Receivable, Recorded Investment	175,309	118,865
Mortgage Loans on Real Estate [Member]
Schedule Of Non Accrual and Performing Restructured Impaired Financing Receivables [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	37,335	37,612
Impaired Financing Receivable Performing Restructured Loans	22,398	20,245
Impaired Financing Receivable, Recorded Investment	59,733	57,857
Real Estate Construction [Member]
Schedule Of Non Accrual and Performing Restructured Impaired Financing Receivables [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	832	1,559
Impaired Financing Receivable Performing Restructured Loans	7,807	8,996
Impaired Financing Receivable, Recorded Investment	8,639	10,555
Commercial Portfolio Segment [Member]
Schedule Of Non Accrual and Performing Restructured Impaired Financing Receivables [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	97,693	40,965
Impaired Financing Receivable Performing Restructured Loans	5,515	5,744
Impaired Financing Receivable, Recorded Investment	103,208	46,709
Consumer Portfolio Segment [Member]
Schedule Of Non Accrual and Performing Restructured Impaired Financing Receivables [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	3,474	3,485
Impaired Financing Receivable Performing Restructured Loans	255	259
Impaired Financing Receivable, Recorded Investment	$ 3,729	$ 3,744