Loans and the Allowance for Loan and Lease Losses (Details) - Credit quality indicators - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	$ 2,767,215	$ 2,539,531
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	2,682,004	2,477,674
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	44,096	19,305
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	40,851	42,263
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	264	289
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	568,969	499,816
Commercial Portfolio Segment [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	533,287	481,638
Commercial Portfolio Segment [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	22,608	3,686
Commercial Portfolio Segment [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	12,810	14,203
Commercial Portfolio Segment [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	264	289
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	1,751,391	1,634,510
Commercial Real Estate Portfolio Segment [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	1,707,191	1,596,606
Commercial Real Estate Portfolio Segment [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	21,488	14,140
Commercial Real Estate Portfolio Segment [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	22,712	23,764
Construction Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	220,267	167,359
Construction Loans [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	218,788	165,880
Construction Loans [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount		1,479
Construction Loans [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	1,479
Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	224,134	234,967
Residential Portfolio Segment [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	220,376	230,772
Residential Portfolio Segment [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	3,758	4,195
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	2,454	2,879
Consumer Portfolio Segment [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	2,362	2,778
Consumer Portfolio Segment [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	$ 92	$ 101