Loans and the Allowance for Loan and Lease Losses (Details) - Aging analysis (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	$ 10,431	$ 12,848
60-89 Days Past Due	5,647	849
90 Days or Greater Past Due	11,016	9,823
Total Past Due	27,094	23,519
Current	2,615,429	2,516,012
Total Loans Receivable	2,642,523	2,539,531
Loans Receivable > 90 Days Past Due and Accruing	638	1,211
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	5,562	6,060
60-89 Days Past Due	554
90 Days or Greater Past Due	3,899	662
Total Past Due	10,015	6,722
Current	552,916	493,094
Total Loans Receivable	562,931	499,816
Loans Receivable > 90 Days Past Due and Accruing	638	45
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	2,567	4,937
60-89 Days Past Due	5,092	638
90 Days or Greater Past Due	4,180	5,961
Total Past Due	11,839	11,535
Current	1,656,471	1,622,975
Total Loans Receivable	1,668,310	1,634,510
Loans Receivable > 90 Days Past Due and Accruing		609
Construction Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	375
Total Past Due	375
Current	180,681	167,359
Total Loans Receivable	181,056	167,359
Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	1,925	1,821
60-89 Days Past Due		210
90 Days or Greater Past Due	2,937	3,200
Total Past Due	4,862	5,231
Current	221,783	229,736
Total Loans Receivable	226,645	234,967
Loans Receivable > 90 Days Past Due and Accruing		557
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	2	30
60-89 Days Past Due	1	1
Total Past Due	3	31
Current	3,578	2,848
Total Loans Receivable	$ 3,581	$ 2,879