Loans and Credit Quality (Details 8) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012
Purchased Credit Impaired Loans Composition [Line Items]
Non-PCI nonaccrual loans	$ 88,948		$ 46,774
Loans and Leases Receivable, Net Reported Amount, Covered	332,564		361,003
Purchased Credit Impaired Loans and Leases [Member]
Purchased Credit Impaired Loans Composition [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	393,591		428,251
Loan Discounts	(42,212)		(45,455)
Loans and Leases Receivable, Allowance, Covered	(18,815)	(16,626)	(21,793)	(23,235)	(27,397)	(26,069)
Loans and Leases Receivable, Net Reported Amount, Covered	332,564		361,003
Mortgage Loans on Real Estate [Member]
Purchased Credit Impaired Loans Composition [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	356,151		412,791
Real Estate Construction [Member]
Purchased Credit Impaired Loans Composition [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	8,506		12,015
Commercial Portfolio Segment [Member]
Purchased Credit Impaired Loans Composition [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	28,532		3,021
Consumer Portfolio Segment [Member]
Purchased Credit Impaired Loans Composition [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	$ 402		$ 424