CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 214,144	$ 224,915
Accounts receivable, net of allowance for credit losses of $10,838 and $10,842 at March 31, 2021 and December 31, 2020, respectively	181,092	160,214
Federal and state income taxes receivable	169	4,428
Inventory	34,369	33,085
Other	57,828	55,314
Total current assets	487,602	477,956
Property and equipment, net	2,627,912	2,761,041
Right of use asset	15,900	16,850
Intangible assets	27,065	30,087
Deposits on equipment purchases	1,958	1,716
Other	11,405	11,419
Total assets	3,171,842	3,299,069
Current liabilities:
Accounts payable	101,165	91,622
Accrued liabilities	164,179	175,004
Lease liability	6,916	7,096
Total current liabilities	272,260	273,722
Long-term lease liability	17,497	19,118
Long-term debt, net of debt discount and issuance costs of $7,066 and $7,271 at March 31, 2021 and December 31, 2020, respectively	901,689	901,484
Deferred tax liabilities, net	56,703	77,676
Other	11,547	11,010
Total liabilities	1,259,696	1,283,010
Commitments and contingencies (see Note 9)
Stockholders' equity:
Preferred stock, par value $0.01; authorized 1,000,000 shares, no shares issued
Common stock, par value $0.01; authorized 400,000,000 shares with 271,192,193 and 271,028,688 issued and 187,789,871 and 187,626,366 outstanding at March 31, 2021 and December 31, 2020, respectively	2,712	2,710
Additional paid-in capital	2,908,125	2,902,236
Retained earnings	361,792	472,014
Accumulated other comprehensive income	5,830	5,412
Treasury stock, at cost, 83,402,322 shares at March 31, 2021 and December 31, 2020	(1,366,313)	(1,366,313)
Total stockholders' equity	1,912,146	2,016,059
Total liabilities and stockholders' equity	$ 3,171,842	$ 3,299,069