Derivative Instruments (Details) $ in Thousands	12 Months Ended
Dec. 31, 2017 USD ($) contract	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Interest Rate Derivatives
Number of interest rate swaps \| contract	3
Aggregate notional amount	$ 96,200	$ 98,900
Termination value of interest rate swap, including accrued interest	2,300
Interest Rate Cash Flow Hedges
Fair value of swaps in other liabilities	2,200	4,900
Amount to be reclassified from accumulated other comprehensive income to increase interest expense over next twelve months	77
Interest Rate Swap [Member] \| Other Comprehensive Income (Loss) [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member]
Interest Rate Cash Flow Hedges
Amount of gain (loss) related to the effective portion recognized in other comprehensive income (loss)	176	(648)	$ (1,884)
Interest Rate Swap [Member] \| Interest Expense [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member]
Interest Rate Cash Flow Hedges
Amount of loss related to the effective portion reclassified to interest expense	(453)	(1,069)	(1,396)
Amount of gain (loss) related to the ineffective portion recognized in interest expense	$ 168	$ (48)	$ (91)

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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The aggregate fair value of assets needed to immediately settle the derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-Subparagraph (f)
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The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
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The effective portion of loss reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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The net gain (loss) during the reporting period due to ineffectiveness in interest rate cash flow hedges. Recognized in earnings.

+ References

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The estimated net amount of unrealized gains or losses on interest rate cash flow hedges as of the balance sheet date expected to be reclassified to earnings within the next twelve months.

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Fair value as of the balance sheet date of all interest rate derivative liabilities designated as cash flow hedging instruments.

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Number of interest rate derivative instruments held by the entity at the reporting date.

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