Income Taxes - Deferred Tax Assets Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating loss carryforwards	$ 3,618,227	$ 2,834,851
Equity compensation	1,594	6,577
Deferred revenue	3,878	8,873
Tax credit and other attribute carryforwards	84,502	97,215
Insurance loss reserves	2,086	2,248
Accrued interest		172,120
Depreciation and amortization for tax in excess of book expense	44,837
Other	110,003	95,588
Subtotal	3,865,127	3,217,472
Valuation allowance	(3,602,144)	(2,813,567)
Deferred tax assets	262,983	403,905
Deferred tax liabilities:
Depreciation and amortization for tax in excess of book expense		80,155
Other	17,388	21,055
Deferred tax liability	17,388	101,210
Net deferred tax assets (liabilities)	245,595	302,695
Balance Sheet Summary :
Deferred income taxes	247,171	305,844
Net noncurrent deferred tax liability	$ (1,576)	$ (3,149)