Derivatives - Effect On Condensed Consolidated Statements of Operations (Details) - Interest rate swap contract - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivatives Designated as Hedging Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Fair value of liability derivatives	$ 363	$ 372
Derivatives Designated as Hedging Instruments \| Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in other comprehensive income before reclassifications	165	80	$ (450)
Derivatives Designated as Hedging Instruments \| Cash Flow Hedging \| Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified from accumulated other comprehensive income to earnings for the effective portion	219	(207)	(626)
Derivatives Designated as Hedging Instruments \| Cash Flow Hedging \| Income tax expense
Derivative Instruments, Gain (Loss) [Line Items]
Income tax benefit (expense)	(61)	47	200
Not Designated as Hedging Instrument \| Cash Flow Hedging \| Income tax expense
Derivative Instruments, Gain (Loss) [Line Items]
Income tax benefit (expense)	185	86	0
Not Designated as Hedging Instrument \| Cash Flow Hedging \| Other, net
Derivative Instruments, Gain (Loss) [Line Items]
Loss recognized in earnings	$ (743)	$ (382)	$ 0

Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Tax

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- Definition

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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- Definition

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

+ References

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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- Definition

Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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