Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating loss carryforwards	$ 550,119	$ 549,107
Depreciation and amortization	187,288	188,161
Accrued payroll expenses	3,073	2,307
Interest expense limitation carryforward	2,033
Deferred revenue	981	42
Other	336	307
Deferred tax assets	743,830	739,924
Less: valuation allowance	(733,047)	(701,727)
Total deferred tax assets	10,783	38,197
Deferred tax liabilities:
Depreciation and amortization		(22,134)
Deferred expenses	(2,433)
Other	(47)	(5)
Total deferred tax liabilities	(2,480)	(22,139)
Net deferred tax assets	8,303	$ 16,058
Indefinitely reinvested earnings	22,200
Estimated taxes if indefinitely reinvested earnings were distributed	1,100
Luxembourg
Deferred tax liabilities:
Gross deferred tax assets expires in 2034	$ 501,600