Derivatives - Narrative (Details)	6 Months Ended
	Jun. 30, 2017 USD ($) derivative_swap	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Derivatives, Fair Value [Line Items]
Collateral requirement threshold	$ 250,000
Collateral posted	300,000		$ 301,000
Derivative notional amount	$ 17,700,000		18,900,000
Number of derivatives | derivative_swap	4
Derivative fee income	$ 16,000	$ 0
Residential Mortgage Holding Company
Derivatives, Fair Value [Line Items]
Commitments to originate mortgage loans held for sale	80,100,000		$ 62,400,000
Variable to Fixed
Derivatives, Fair Value [Line Items]
Derivative notional amount	$ 8,800,000
Number of derivatives | derivative_swap	2
Fixed to Variable
Derivatives, Fair Value [Line Items]
Derivative notional amount	$ 8,800,000
Number of derivatives | derivative_swap	2