Loans and Credit Quality (Details 8) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Purchased Credit Impaired Loans Composition [Line Items]
Loans and Leases Receivable, Net Reported Amount, Covered	$ 241,587	$ 276,792
Purchased Credit Impaired Loans and Leases [Member]
Purchased Credit Impaired Loans Composition [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	302,828	340,639
Loan Discounts	(48,543)	(49,848)
Loans and Leases Receivable, Allowance, Covered	(12,698)	(13,999)	(21,200)	(21,793)
Loans and Leases Receivable, Net Reported Amount, Covered	241,587	276,792
Mortgage Loans on Real Estate [Member]
Purchased Credit Impaired Loans Composition [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	268,777	299,660
Real Estate Construction [Member]
Purchased Credit Impaired Loans Composition [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	2,540	7,743
Commercial Portfolio Segment [Member]
Purchased Credit Impaired Loans Composition [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	31,185	32,904
Consumer Portfolio Segment [Member]
Purchased Credit Impaired Loans Composition [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	$ 326	$ 332