Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating activities:
Net loss	$ (861,940)	$ (73,328)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation	93,043	86,898
Loss on impairment of assets	774,028
(Gain) loss on disposition of assets	(3,433)	4,287
Deferred tax provision	(13,797)	(7,769)
Stock-based compensation expense	1,543	1,414
Contract liabilities, net	34,285	11,980
Contract assets, net	3,092	(1,922)
Deferred contract costs, net	(14,576)	(6,244)
Other assets, noncurrent	(393)	98
Other liabilities, noncurrent	(3,346)	(570)
Other	451	(1,517)
Changes in operating assets and liabilities:
Accounts receivable	(17,307)	(20,761)
Prepaid expenses and other current assets	131	604
Accounts payable and accrued liabilities	(9,586)	13,329
Taxes payable	(5,036)	(3,637)
Net cash (used in) provided by operating activities	(22,841)	2,862
Investing activities:
Capital expenditures	(74,850)	(85,890)
Proceeds from maturities of marketable securities		1,000,000
Purchase of marketable securities		(948,298)
Proceeds from disposition of assets, net of disposal costs	4,548	95
Net cash used in investing activities	(70,302)	(34,093)
Financing activities:
Borrowings under Credit Facility	436,000
Other		(2)
Net cash provided by (used in) financing activities	436,000	(2)
Net change in cash and cash equivalents	342,857	(31,233)
Cash and cash equivalents, beginning of period	156,281	154,073
Cash and cash equivalents, end of period	$ 499,138	$ 122,840