CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 246,781	$ 174,185
Accounts receivable, net of allowance for credit losses of $12,122 and $6,516 at June 30, 2020 and December 31, 2019, respectively	157,981	339,699
Federal and state income taxes receivable	8,725	6,397
Inventory	34,977	36,357
Other	69,071	75,177
Total current assets	517,535	631,815
Property and equipment, net	3,033,829	3,306,677
Right of use asset	18,699	31,275
Goodwill and intangible assets	38,336	444,004
Deposits on equipment purchases	6,676	8,066
Other	9,730	17,778
Total assets	3,624,805	4,439,615
Current liabilities:
Accounts payable	72,958	170,475
Federal and state income taxes payable		342
Accrued liabilities	190,372	219,850
Lease liability	8,809	9,935
Total current liabilities	272,139	400,602
Long-term lease liability	23,556	26,644
Long-term debt, net of debt discount and issuance costs of $7,860 and $8,460 at June 30, 2020 and December 31, 2019, respectively	967,140	966,540
Deferred tax liabilities, net	115,740	202,959
Other	17,357	9,250
Total liabilities	1,395,932	1,605,995
Commitments and contingencies (see Note 9)
Stockholders' equity:
Preferred stock, par value $.01; authorized 1,000,000 shares, no shares issued
Common stock, par value $.01; authorized 400,000,000 shares with 270,569,043 and 269,372,257 issued and 187,241,124 and 192,035,870 outstanding at June 30, 2020 and December 31, 2019, respectively	2,706	2,694
Additional paid-in capital	2,889,163	2,875,680
Retained earnings	698,286	1,294,902
Accumulated other comprehensive income	4,787	5,478
Treasury stock, at cost, 83,327,919 and 77,336,387 shares at June 30, 2020 and December 31, 2019, respectively	(1,366,069)	(1,345,134)
Total stockholders' equity	2,228,873	2,833,620
Total liabilities and stockholders' equity	$ 3,624,805	$ 4,439,615