Supplemental Guarantors Consolidating Condensed Financial Information - Statement of Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Condensed Financial Statements, Captions
Net loss	$ (9,811)	$ (9,636)	$ (11,714)	$ (23,015)
Foreign currency translation adjustments	(2,369)	2,569	(5,565)	3,391
Comprehensive loss	(12,180)	(7,067)	(17,279)	(19,624)
Consolidation, Eliminations [Member]
Condensed Financial Statements, Captions
Net loss	5,633	3,398	1,510	10,918
Foreign currency translation adjustments	0	0	24	111
Comprehensive loss	5,633	3,398	1,534	11,029
Parent [Member] \| Reportable Legal Entities [Member]
Condensed Financial Statements, Captions
Net loss	(9,811)	(9,636)	(11,714)	(23,015)
Foreign currency translation adjustments	0	0	0	0
Comprehensive loss	(9,811)	(9,636)	(11,714)	(23,015)
Guarantor Subsidiaries [Member] \| Reportable Legal Entities [Member]
Condensed Financial Statements, Captions
Net loss	(3,274)	(3,472)	1,164	(10,867)
Foreign currency translation adjustments	0	0	0	0
Comprehensive loss	(3,274)	(3,472)	1,164	(10,867)
Non-Guarantor Subsidiaries [Member] \| Reportable Legal Entities [Member]
Condensed Financial Statements, Captions
Net loss	(2,359)	74	(2,674)	(51)
Foreign currency translation adjustments	(2,369)	2,569	(5,589)	3,280
Comprehensive loss	$ (4,728)	$ 2,643	$ (8,263)	$ 3,229

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 5
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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature, attributable to parent entity.

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