Loans - Narrative (Details)	3 Months Ended
	Mar. 31, 2017 USD ($) contract	Mar. 31, 2016 USD ($) contract	Dec. 31, 2016 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructurings (TDRs)	$ 5,900,000		$ 200,000
Troubled debt restructurings specific reserve	1,300,000
TDR loans on nonaccrual status	5,900,000		100,000
Financing Receivable, modifications, accrual status	20,000		20,000
Financing receivable, modifications	5,781,000	$ 0
Loans classified as impaired	$ 8,858,000		2,887,000
Number of Loans | contract	3	0
Performing financial instruments
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans classified as impaired	$ 900,000		$ 1,300,000
Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Modifications, reduction of stated interest rate, period	6 months
Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Modifications, reduction of stated interest rate, period	16 months