Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash Flows From Operating Activities:
Net income	$ 113,659	$ 55,841
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	120,325	119,635
Amortization of debt issuance costs and discounts	2,622	3,460
Loss on impairment or disposal of assets, net	3,770	12,477
Deferred income tax provision	39,705	24,478
Equity-based compensation	8,444	18,620
Changes in assets and liabilities:
Accounts receivable	5,817	(36,806)
Inventories	(919)	(3,374)
Prepaid expenses and other current assets	5,058	2,866
Accounts payable and accrued expenses	3,775	8,649
Accrued salaries, wages and benefits	(4,505)	10,225
Deferred revenue	15,483	36,586
Other accrued liabilities	109	14,902
Right-of-use assets and operating lease obligations	370
Other assets and liabilities	(30)	(101)
Net cash provided by operating activities	313,683	267,458
Cash Flows From Investing Activities:
Capital expenditures	(152,880)	(140,878)
Other investing activities, net	24	(349)
Net cash used in investing activities	(152,856)	(141,227)
Cash Flows From Financing Activities:
Repayments of long-term debt	(11,629)	(17,780)
Proceeds from draws on revolving credit facility	269,000	55,000
Repayments of revolving credit facility	(249,000)	(70,000)
Purchase of treasury stock	(150,000)
Payment of tax withholdings on equity-based compensation through shares withheld	(4,621)	(2,942)
Exercise of stock options	3,578	3,191
Other financing activities	(572)	(325)
Net cash used in financing activities	(143,244)	(32,856)
Change in Cash and Cash Equivalents, including Restricted Cash	17,583	93,375
Cash and Cash Equivalents, including Restricted Cash—Beginning of period	35,007	33,997
Cash and Cash Equivalents, including Restricted Cash—End of period	52,590	127,372
Supplemental Disclosure of Noncash Investing Activities:
Capital expenditures in accounts payable	$ 26,260	$ 23,125