Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating activities:
Net loss	$ (1,006,760)	$ (187,316)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation	167,878	175,151
Loss on impairment of assets	774,028
Reorganization items, net	33,318
Gain on disposition of assets	(3,653)	(5,149)
Deferred tax provision	(14,986)	(31,125)
Stock-based compensation expense	5,636	2,956
Contract liabilities, net	19,809	14,017
Contract assets, net	1,337	(566)
Deferred contract costs, net	(9,492)	26,879
Long-term employee remuneration programs	(6,204)	(954)
Noncurrent collateral deposits	(18,262)
Other assets, noncurrent	(6,186)	(118)
Other liabilities, noncurrent	(1,417)	3
Other	4,493	(346)
Changes in operating assets and liabilities:
Accounts receivable	54,023	5,534
Prepaid expenses and other current assets	950	(2,002)
Accounts payable and accrued liabilities	42,139	9,961
Taxes payable	(3,918)	(9,608)
Net cash provided by (used in) operating activities	32,733	(2,683)
Investing activities:
Capital expenditures	(118,379)	(172,335)
Proceeds from maturities of marketable securities		2,025,000
Purchase of marketable securities		(1,872,107)
Proceeds from disposition of assets, net of disposal costs	4,767	15,573
Net cash used in investing activities	(113,612)	(3,869)
Financing activities:
Borrowings under credit facility	436,000
Other		(12)
Net cash provided by (used in) financing activities	436,000	(12)
Net change in cash, cash equivalents and restricted cash	355,121	(6,564)
Cash, cash equivalents and restricted cash, beginning of period	156,281	154,073
Cash, cash equivalents and restricted cash, end of period	$ 511,402	$ 147,509