Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating activities:
Net loss	$ (361,681)	$ (861,940)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	74,626	93,043
Loss on impairment of assets	197,027	774,028
Gain on disposition of assets	(5,401)	(3,433)
Deferred tax provision	(5,565)	(13,797)
Stock-based compensation expense		1,543
Contract liabilities, net	6,974	34,285
Contract assets, net	(326)	3,092
Deferred contract costs, net	(9,176)	(14,576)
Other assets, noncurrent	1,279	(393)
Other liabilities, noncurrent	(110)	(3,346)
Other	282	451
Changes in operating assets and liabilities:
Accounts receivable	(14,993)	(17,307)
Prepaid expenses and other current assets	(1,340)	131
Accounts payable and accrued liabilities	68,274	(9,586)
Taxes payable	922	(5,036)
Net cash used in operating activities	(49,208)	(22,841)
Investing activities:
Capital expenditures	(40,617)	(74,850)
Proceeds from disposition of assets, net of disposal costs	7,400	4,548
Net cash used in investing activities	(33,217)	(70,302)
Financing activities:
Borrowings under credit facility		436,000
Debt issuance costs and arrangement fees	(2,290)
Net cash (used in) provided by financing activities	(2,290)	436,000
Net change in cash, cash equivalents and restricted cash	(84,715)	342,857
Cash, cash equivalents and restricted cash, beginning of period	430,380	156,281
Cash, cash equivalents and restricted cash, end of period	$ 345,665	$ 499,138