Loans - (Loan Portfolio Composition Including Carrying Value by Segment of Loans Accounted for under ASC Topic 310-30) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Loans [Line Items]
Total Loans	$ 2,953,655	$ 2,860,921	$ 2,592,047
% of Total	100.00%	100.00%
Commercial Loan [Member]
Loans [Line Items]
Total Loans	$ 1,641,596	$ 1,560,430
% of Total	55.60%	54.60%
Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	$ 537,993	$ 526,792
% of Total	18.20%	18.40%
Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	$ 746,455	$ 744,885
% of Total	25.30%	26.00%
Consumer [Member]
Loans [Line Items]
Total Loans	$ 27,611	$ 28,814
% of Total	0.90%	1.00%
ASC 310-30 [Member]
Loans [Line Items]
Total Loans	$ 140,064	$ 145,852	$ 179,507
ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total Loans	36,935	39,280
ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	86,842	89,150
ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	15,470	16,524
ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total Loans	817	898
Non ASC 310-30 [Member]
Loans [Line Items]
Total Loans	2,813,591	2,715,069
Non ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total Loans	1,604,661	1,521,150
Non ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	451,151	437,642
Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	730,985	728,361
Non ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total Loans	$ 26,794	$ 27,916