Derivative Instruments - Narrative (Details)	1 Months Ended
	Jun. 30, 2014 USD ($) derivative_instrument	Jun. 30, 2018 USD ($)	Apr. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)	Apr. 30, 2012 USD ($) derivative_instrument
Interest rate contracts with corporate customers
Derivative Instruments (Textual) [Abstract]
Notional amount		$ 219,738,000
Offsetting interest rate contracts with other financial institutions
Derivative Instruments (Textual) [Abstract]
Notional amount		219,738,000
Interest rate swaps
Derivative Instruments (Textual) [Abstract]
Number of instruments held | derivative_instrument	2
Floating rate liability at the bank level, derivative one
Derivative Instruments (Textual) [Abstract]
Notional amount	$ 15,000,000
Term of contract	4 years
Floating rate liability at the bank level, derivative two
Derivative Instruments (Textual) [Abstract]
Notional amount	$ 15,000,000
Term of contract	5 years
Cash flow hedging
Derivative Instruments (Textual) [Abstract]
Notional amount			$ 30,000,000		$ 32,000,000
Number of instruments held | derivative_instrument					2
Commitments to fund fixed-rate residential mortgage loans
Derivative Instruments (Textual) [Abstract]
Notional amount		196,667,000		$ 131,000,000
Commitments to sell residential mortgage loans
Derivative Instruments (Textual) [Abstract]
Notional amount		$ 374,000,000		$ 199,000,000