CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 174,185	$ 245,029
Accounts receivable, net of allowance for doubtful accounts of $6,516 and $2,312 at December 31, 2019 and 2018, respectively	339,699	558,817
Federal and state income taxes receivable	6,397	4,110
Inventory	36,357	65,579
Other	75,177	76,662
Total current assets	631,815	950,197
Property and equipment, net	3,306,677	4,002,549
Right of use asset	31,275
Goodwill and intangible assets	444,004	477,640
Deposits on equipment purchases	8,066	12,040
Other	17,778	27,440
Total assets	4,439,615	5,469,866
Current liabilities:
Accounts payable	170,475	288,962
Federal and state income taxes payable	342	1,408
Accrued liabilities	219,850	235,946
Lease liability	9,935
Total current liabilities	400,602	526,316
Long-term lease liability	26,644
Long-term debt, net of debt discount and issuance costs of $8,460 and $5,795 at December 31, 2019 and 2018, respectively	966,540	1,119,205
Deferred tax liabilities, net	202,959	306,161
Other	9,250	12,761
Total liabilities	1,605,995	1,964,443
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 269,372,257 and 267,315,526 issued and 192,035,870 and 213,614,430 outstanding at December 31, 2019 and 2018, respectively	2,694	2,673
Additional paid-in capital	2,875,680	2,827,154
Retained earnings	1,294,902	1,753,557
Accumulated other comprehensive income	5,478	2,487
Treasury stock, at cost, 77,336,387 shares and 53,701,096 shares at December 31, 2019 and 2018, respectively	(1,345,134)	(1,080,448)
Total stockholders’ equity	2,833,620	3,505,423
Total liabilities and stockholders’ equity	$ 4,439,615	$ 5,469,866