Derivatives - Narrative (Details)	12 Months Ended
	Dec. 31, 2017 USD ($) derivative_instrument	Dec. 31, 2016 USD ($)
Derivative [Line Items]
Notional Amount	$ 9,886,000
Fair value of derivative asset	420,000	$ 993,000
Interest Rate Cap
Derivative [Line Items]
Notional Amount	$ 10,000,000
Number of positions | derivative_instrument	1
Premium Paid	$ 70,000
Derivative cap interest rate (as a percent)	2.00%
Fair value of derivative asset	$ 1,000
Designated as Hedging Instrument | Interest Rate Swap One
Derivative [Line Items]
Pay Rate (as a percent)	2.59%
Notional Amount	$ 5,155,000
Number of positions | derivative_instrument	1
Designated as Hedging Instrument | Interest Rate Swap Two
Derivative [Line Items]
Pay Rate (as a percent)	1.43%
Notional Amount	$ 10,000,000
Number of positions | derivative_instrument	1
Designated as Hedging Instrument | Interest Rate Swap
Derivative [Line Items]
Amounts included in accumulated other comprehensive income as unrealized losses	$ 8,000
Designated as Hedging Instrument | Operating Expense
Derivative [Line Items]
Hedge ineffectiveness identified	0
Not Designated as Hedging Instrument | Other Operating Income (Expense) | Interest Rate Cap
Derivative [Line Items]
Change in fair value of derivative asset	$ 6,000
Cash Flow Hedging | Designated as Hedging Instrument | Interest Rate Swap One
Derivative [Line Items]
Pay Rate (as a percent)	2.59%
Notional Amount	$ 5,200,000.0
Derivative term	10 years
Collateral reserved for swap	$ 400,000
Cash Flow Hedging | Designated as Hedging Instrument | Interest Rate Swap Two
Derivative [Line Items]
Pay Rate (as a percent)	1.43%
Notional Amount	$ 10,000,000.0
Derivative term	5 years
Collateral reserved for swap	$ 600,000