CONSOLIDATED BALANCE SHEET - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 140,113	$ 200,227
Restricted cash	11,578	13,556
Accounts receivable, net	214,724	209,023
Income taxes receivable	6,171	129,795
Inventories	15,270	13,932
Derivative instruments	26,209	31
Other current assets	1,650	1,684
Total current assets	415,715	568,248
Properties and equipment, net (Successful efforts method)	4,044,606	3,855,706
Other assets	63,211	63,291
TOTAL ASSETS	4,523,532	4,487,245
Current liabilities
Accounts payable	162,081	189,811
Current portion of long-term debt	188,000	87,000
Accrued liabilities	22,374	31,290
Interest payable	17,771	19,933
Total current liabilities	390,226	328,034
Long-term debt, net	945,924	1,133,025
Deferred income taxes	774,195	702,104
Asset retirement obligations	85,489	71,598
Postretirement benefits	30,713	32,713
Other liabilities	81,278	68,284
Total liabilities	2,307,825	2,335,758
Commitments and contingencies
Stockholders' equity
Common stock: Authorized — 960,000,000 shares of $0.10 par value in 2020 and 2019, respectively and Issued — 476,881,991 shares and 476,881,991 shares in 2020 and 2019, respectively	47,783	47,688
Additional paid-in capital	1,804,354	1,782,427
Retained earnings	2,184,352	2,143,213
Accumulated other comprehensive income	2,419	1,360
Treasury Stock, Value	(1,823,201)	(1,823,201)
Total stockholders' equity	2,215,707	2,151,487
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 4,523,532	$ 4,487,245