Derivatives - Additional Information (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017 USD ($) InterestRateSwap	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($) InterestRateSwap	Dec. 31, 2017 USD ($)
Derivative [Line Items]
Notional amount	$ 100,000		$ 100,000
Interest rate swap maturity date		Jun. 30, 2024
Other Assets
Derivative [Line Items]
Derivative contracts collateral amount		$ 10,913		$ 4,309
Designated as Hedging
Derivative [Line Items]
Notional amount		30,000		130,000
Subordinated Debentures
Derivative [Line Items]
Number of derivative instruments | InterestRateSwap	2		2
Long-term debt	$ 30,930		$ 30,930
Interest Rate Swaps
Derivative [Line Items]
Number of derivative instruments | InterestRateSwap	3		3
Other comprehensive income to be accreted		1,510
Interest Rate Swaps | Designated as Hedging
Derivative [Line Items]
Fair value of interest rate swap				1,127
Gain on cancellation of swaps, tax-adjusted amount		1,564
Interest Rate Swaps | Subordinated Debentures
Derivative [Line Items]
Notional amount	$ 30,000		$ 30,000
Fair value of interest rate swap		$ 1,519		$ 305
Interest Rate Swaps Three
Derivative [Line Items]
Notional amount	$ 30,000		$ 30,000
Derivative notional amount maturity period	3 years		3 years
Interest Rate Swaps Four
Derivative [Line Items]
Notional amount	$ 35,000		$ 35,000
Derivative notional amount maturity period	4 years		4 years
Interest Rate Swaps Five
Derivative [Line Items]
Notional amount	$ 35,000		$ 35,000
Derivative notional amount maturity period	5 years		5 years
Maximum
Derivative [Line Items]
Lock in period for interest rates		45 days