Supplemental Guarantor Information (Condensed Consolidating Statements of Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Financial Statements, Captions [Line Items]
Total Revenues	$ 851,307	$ 1,425,369	$ 1,478,857
Cost or revenues	580,129	925,082	970,488
Loss from operations before income taxes	(295,276)	(82,379)	(470,406)
Income taxes	(13,928)	(4,626)	(43,003)
Net loss from continuing operations	(281,348)	(77,753)	(427,403)
Loss from discontinued operations, net of income tax	(114,882)	(177,968)	(430,712)
Net loss	(396,230)	(255,721)	$ (858,115)
Obligor Group [Member]
Condensed Financial Statements, Captions [Line Items]
Total Revenues	641,216	1,126,456
Cost or revenues	432,363	723,451
Loss from operations before income taxes	(273,825)	(92,731)
Income taxes	(17,602)	6,102
Net loss from continuing operations	(256,223)	(98,833)
Loss from discontinued operations, net of income tax	(114,882)	(177,968)
Net loss	$ (371,105)	$ (276,801)