Loans - Narrative (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016 USD ($) contract	Sep. 30, 2015 contract	Sep. 30, 2016 USD ($) contract	Sep. 30, 2015 contract	Dec. 31, 2015 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchased credit-impaired (PCI) loans held-for-investment	$ 32,793,000		$ 32,793,000		$ 33,115,000
Investment in non accrual loans	8,800,000		$ 8,800,000		8,800,000
Criteria days for delinquent status			90 days
Impairment of loans	7,200,000		$ 7,200,000		6,700,000
Principal balance of loans on non accrual status	500,000		500,000
Loans on non accrual status with principal balances below threshold definition of an impaired loan	1,600,000		1,600,000		2,100,000
90 Days or More Past Due and Accruing	1,800,000		1,800,000		15,000
Carrying balances of loans not written down	$ 13,400,000		$ 13,400,000		14,500,000
Number of relationships (contract) | contract	0	1	0	9
Troubled debt restructurings	$ 25,400,000		$ 25,400,000		$ 26,600,000
Number of TDR loans restructured that subsequently defaulted (contract) | contract			3	0
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of Purchase Credit Impaired Loans			36.50%		27.90%
Loan to value ratio (percent)	35.00%		35.00%
Number of TDR loans restructured that subsequently defaulted (contract) | contract			1
Commercial real estate | 90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment of subsequently defaulted loans			$ 1,800,000
Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of Purchase Credit Impaired Loans			44.00%		52.40%
One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan to value ratio (percent)	60.00%		60.00%
Number of TDR loans restructured that subsequently defaulted (contract) | contract			2
One-to-four family residential mortgage | 90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment of subsequently defaulted loans			$ 361,000
Hopewell Valley Community Bank
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchased credit-impaired (PCI) loans held-for-investment					$ 4,900,000