Supplemental Guarantor Information (Consolidating Statements of Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	$ (38,441)	$ (71,050)	$ (47,705)	$ (21,816)	$ (26,390)	$ (59,724)	$ (157,196)	$ (107,930)
Change in cumulative translation adjustment, net of tax	(2,967)	$ (1,916)	$ 1,073	(826)	$ (7,053)	$ 4,388	(3,810)	(3,491)
Comprehensive loss	(41,408)			(22,642)			(161,006)	(111,421)
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	46,109			2,687			208,539	95,278
Change in cumulative translation adjustment, net of tax	5,934			1,652			7,620	6,982
Comprehensive loss	52,043			4,339			216,159	102,260
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	(38,441)			(21,816)			(157,196)	(107,930)
Change in cumulative translation adjustment, net of tax	(2,967)			(826)			(3,810)	(3,491)
Comprehensive loss	(41,408)			(22,642)			(161,006)	(111,421)
Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	(38,441)			(21,816)			(157,196)	(107,930)
Change in cumulative translation adjustment, net of tax	(2,967)			(826)			(3,810)	(3,491)
Comprehensive loss	(41,408)			(22,642)			(161,006)	(111,421)
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	(6,117)			18,187			(53,867)	29,432
Comprehensive loss	(6,117)			18,187			(53,867)	29,432
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	(1,551)			942			2,524	(16,780)
Change in cumulative translation adjustment, net of tax	(2,967)			(826)			(3,810)	(3,491)
Comprehensive loss	$ (4,518)			$ 116			$ (1,286)	$ (20,271)