Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash Flows From Operating Activities:
Net loss	$ (44,884)	$ (56,519)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	36,558	38,013
Amortization of debt issuance costs and discounts	1,717	822
Deferred income tax benefit	(5,773)	(20,805)
Equity-based compensation	4,473	(3,601)
Other, including loss on sale or disposal of assets, net	487	(594)
Changes in assets and liabilities:
Accounts receivable	(28,548)	7,005
Inventories	1,854	(1,459)
Prepaid expenses and other current assets	(2,533)	(9,586)
Accounts payable and accrued expenses	(2,226)	13,720
Accrued salaries, wages and benefits	4,246	(3,156)
Deferred revenue	66,386	25,875
Other accrued liabilities	(11,887)	(28,349)
Right of use assets and operating lease liabilities	115	133
Other assets and liabilities	(1,592)	(2,266)
Net cash provided by (used in) operating activities	18,393	(40,767)
Cash Flows From Investing Activities:
Capital expenditures	(15,298)	(49,249)
Net cash used in investing activities	(15,298)	(49,249)
Cash Flows From Financing Activities:
Repayments of long-term debt	(3,876)	(3,876)
Proceeds from draws on revolving credit facility		272,500
Repayments of revolving credit facility		(10,000)
Purchase of treasury stock		(12,406)
Payment of tax withholdings on equity-based compensation through shares withheld	(1,971)	(3,160)
Exercise of stock options	2,393	203
Debt issuance costs		(234)
Other financing activities	(2,158)	(208)
Net cash (used in) provided by financing activities	(5,612)	242,819
Change in Cash and Cash Equivalents, including Restricted Cash	(2,517)	152,803
Cash and Cash Equivalents, including Restricted Cash—Beginning of period	435,225	40,925
Cash and Cash Equivalents, including Restricted Cash—End of period	432,708	193,728
Supplemental Disclosure of Noncash Investing and Financing Activities
Capital expenditures in accounts payable	15,763	$ 41,208
Other financing arrangements	$ 4,239