Consolidated Statements of Changes in Stockholders Equity (Deficit) - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Warrants	Additional Paid-In Capital	Accumulated Deficit	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjustment
Increase (Decrease) in Stockholders' Equity
Cumulative effect of adoption of ASU 2016-02	$ 847,721	$ (57)	$ 36	$ 88,516	$ 1,055,164	$ (295,995)	$ (57)
Beginning Balance (in shares) at Dec. 31, 2018			35,687	6,604
Beginning Balance at Dec. 31, 2018	847,721	(57)	$ 36	$ 88,516	1,055,164	(295,995)	(57)
Increase (Decrease) in Stockholders' Equity
Issuance of stock awards, net of cancellations (in shares)			40
Common stock issued for general unsecured claims (in shares)			45
Stock-based compensation	4,460				4,460
Issuance of warrants for general unsecured claims (in shares)				55
Issuance of warrants for general unsecured claims				$ 4	(4)
Cash paid for tax withholdings on vested stock awards	(367)				(367)
Cumulative effect of adoption of ASU 2016-02	402,452	$ (57)	$ 36	$ 88,520	1,059,253	(745,357)	$ (57)
Net loss	$ (449,305)					(449,305)
Ending Balance (in shares) at Dec. 31, 2019	35,772		35,772	6,659
Ending Balance at Dec. 31, 2019	$ 402,452		$ 36	$ 88,520	1,059,253	(745,357)
Increase (Decrease) in Stockholders' Equity
Cumulative effect of adoption of ASU 2016-02	402,452		$ 36	$ 88,520	1,059,253	(745,357)
Issuance of stock awards, net of cancellations (in shares)			96
Common stock issued for general unsecured claims (in shares)			60
Stock-based compensation	3,031				3,031
Issuance of warrants for general unsecured claims (in shares)				75
Cash paid for tax withholdings on vested stock awards	(64)				(64)
Cumulative effect of adoption of ASU 2016-02	128,066		$ 36	$ 88,520	1,062,220	(1,022,710)
Net loss	$ (277,353)					(277,353)
Ending Balance (in shares) at Dec. 31, 2020	35,928		35,928	6,734
Ending Balance at Dec. 31, 2020	$ 128,066		$ 36	$ 88,520	1,062,220	(1,022,710)
Increase (Decrease) in Stockholders' Equity
Cumulative effect of adoption of ASU 2016-02	$ 128,066		$ 36	$ 88,520	$ 1,062,220	$ (1,022,710)