Business Combinations (Narrative) (Details)		12 Months Ended
	Oct. 01, 2016 USD ($) $ / shares shares	Dec. 31, 2016 USD ($)
Business Acquisition [Line Items]
Goodwill		$ 15,590,000
East River Bank (“ERB”) [Member]
Business Acquisition [Line Items]
Business acquisition date of acquisition agreement		Apr. 04, 2016
Business acquisition effective date of acquisition		Oct. 01, 2016
Business combination shares conversion ratio	0.6562
Business acquisition share price | $ / shares	$ 18.65
Business combination number of outstanding common stock shares to be exchanged | shares	2,085,662
Business combination percentage of outstanding common stock	85.30%
Aggregate cash consideration payable to ERB shareholders	$ 6,700,000
Goodwill	15,590,000
Core deposit and other intangible	508,000
Loans receivable with a gross amortized cost basis	312,279,000
Merger related costs incurred	4,700,000
East River Bank (“ERB”) [Member] | Interest Rate Fair Value Adjustment on Pools of Homogeneous Loan [Member]
Business Acquisition [Line Items]
Fair value discount amount	200,000
East River Bank (“ERB”) [Member] | Credit Fair Value Adjustment on Pools of Homogeneous Loans [Member]
Business Acquisition [Line Items]
Fair value discount amount	$ 4,846,000
East River Bank (“ERB”) [Member] | Options to Purchase ERB Common Stock Outstanding Shares [Member]
Business Acquisition [Line Items]
Business combination number of common stock shares acquired | shares	248,000
Cash paid in business combination	$ 1,900,000
East River Bank (“ERB”) [Member] | Payment in Lieu Of Fractional Shares [Member]
Business Acquisition [Line Items]
Cash paid in business combination	$ 2,399
East River Bank (“ERB”) [Member] | Core Deposit Intangible [Member]
Business Acquisition [Line Items]
Intangible assets amortization period		10 years
Amortization expense in 2017		$ 90,000
Amortization expense in 2018		81,000
Amortization expense in 2019		72,000
Amortization expense in 2020		62,000
Amortization expense in 2021		53,000
Amortization expense after 2021		$ 127,000