Derivative Financial Instruments - Narrative (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($) interest_rate_swap interest_rate_cap instrument	Dec. 31, 2017 USD ($) interest_rate_swap interest_rate_cap
Derivative [Line Items]
Estimated amount to be transferred from accumulated other comprehensive income to earnings	$ 315
Termination value of derivatives in a net liability position	557
Derivative collateral posted	3,315
Not Designated as Hedging Instrument
Derivative [Line Items]
Notional amount of interest rate derivatives	$ 416,506
Federal Home Loan Bank Advances
Derivative [Line Items]
Number of debt instruments held | instrument	3
Cash Flow Hedging | Interest Rate Swap
Derivative [Line Items]
Number of interest rate derivatives held | interest_rate_swap	5	5
Notional amount of interest rate derivatives	$ 56,000	$ 56,000
Cash Flow Hedging | Interest Rate Swap | Trust Preferred Debt
Derivative [Line Items]
Notional amount of interest rate derivatives	26,000
Cash Flow Hedging | Interest Rate Swap | Federal Home Loan Bank Advances
Derivative [Line Items]
Notional amount of interest rate derivatives	$ 30,000
Cash Flow Hedging | Interest Rate Cap
Derivative [Line Items]
Number of interest rate derivatives held | interest_rate_cap	1	1
Notional amount of interest rate derivatives	$ 13,000	$ 13,000
Cash Flow Hedging | Interest Rate Cap | Trust Preferred Debt
Derivative [Line Items]
Notional amount of interest rate derivatives	$ 13,000