Derivatives - Narrative (Details)	9 Months Ended
	Sep. 30, 2017 USD ($) derivative_swap	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Derivatives, Fair Value [Line Items]
Collateral requirement threshold	$ 250,000
Collateral posted	300,000		$ 301,000
Derivative notional amount	$ 13,000,000		18,900,000
Number of derivatives | derivative_swap	2
Derivative fee income	$ 26,000	$ 0
Residential Mortgage Holding Company
Derivatives, Fair Value [Line Items]
Commitments to originate mortgage loans held for sale	68,600,000		$ 62,400,000
Variable to Fixed
Derivatives, Fair Value [Line Items]
Derivative notional amount	$ 6,500,000
Number of derivatives | derivative_swap	1
Fixed to Variable
Derivatives, Fair Value [Line Items]
Derivative notional amount	$ 6,500,000
Number of derivatives | derivative_swap	1
Subordinated Debt
Derivatives, Fair Value [Line Items]
Junior subordinated debenture	$ 10,000,000.0
Junior subordinated debenture, interest rate	3.72%
Designated as Hedging Instrument | Interest rate swaps
Derivatives, Fair Value [Line Items]
Variable interest rate	2.69%
Cash pledged to collateralize fair value exposure on interest rate swap	$ 300,000
Unrealized gain on interest rate swap	$ 127,000
Designated as Hedging Instrument | LIBOR | Interest rate swaps
Derivatives, Fair Value [Line Items]
Basis spread on variable rate	1.37%