Loans - (Loan Portfolio Composition Including Carrying Value by Segment of Loans Accounted for under ASC Topic 310-30) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016
Loans [Line Items]
Total Loans	$ 3,087,945	$ 2,860,921	$ 2,738,504
% of Total	100.00%	100.00%
Commercial Loan [Member]
Loans [Line Items]
Total Loans	$ 1,775,454	$ 1,560,430
% of Total	57.50%	54.60%
Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	$ 557,020	$ 526,792
% of Total	18.00%	18.40%
Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	$ 728,511	$ 744,885
% of Total	23.60%	26.00%
Consumer [Member]
Loans [Line Items]
Total Loans	$ 26,960	$ 28,814
% of Total	0.90%	1.00%
ASC 310-30 [Member]
Loans [Line Items]
Total Loans	$ 134,427	$ 145,852
ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total Loans	35,978	39,280
ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	83,785	89,150
ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	14,012	16,524
ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total Loans	652	898
Non ASC 310-30 [Member]
Loans [Line Items]
Total Loans	2,953,518	2,715,069
Non ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total Loans	1,739,476	1,521,150
Non ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	473,235	437,642
Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	714,499	728,361
Non ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total Loans	$ 26,308	$ 27,916