Supplemental Guarantors Consolidating Condensed Financial Information (Statement of Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Condensed Financial Statements, Captions
Net income (loss)	$ (6,344)	$ (5,443)	$ (29,359)	$ (28,542)
Foreign currency translation adjustments	4,752	(861)	8,143	5,575
Comprehensive income (loss)	(1,592)	(6,304)	(21,216)	(22,967)
Consolidation, Eliminations [Member]
Condensed Financial Statements, Captions
Net income (loss)	(4,904)	(1)	6,014	13,891
Foreign currency translation adjustments	0	1	111	84
Comprehensive income (loss)	(4,904)	0	6,125	13,975
Parent [Member]
Condensed Financial Statements, Captions
Net income (loss)	(6,344)	(5,443)	(29,359)	(28,542)
Foreign currency translation adjustments	0	0	0	0
Comprehensive income (loss)	(6,344)	(5,443)	(29,359)	(28,542)
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions
Net income (loss)	(129)	591	(10,996)	(10,658)
Foreign currency translation adjustments	0	0	0	0
Comprehensive income (loss)	(129)	591	(10,996)	(10,658)
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions
Net income (loss)	5,033	(590)	4,982	(3,233)
Foreign currency translation adjustments	4,752	(862)	8,032	5,491
Comprehensive income (loss)	$ 9,785	$ (1,452)	$ 13,014	$ 2,258