CONDENSED CONSOLIDATED BALANCE SHEET - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 117,164	$ 200,227
Restricted cash	11,578	13,556
Accounts receivable, net	117,918	209,023
Income taxes receivable	155,343	129,795
Inventories	17,948	13,932
Derivative instruments	40,636	31
Other current assets	3,347	1,684
Total current assets	463,934	568,248
Properties and equipment, net (Successful efforts method)	4,002,492	3,855,706
Other assets	61,444	63,291
Total assets	4,527,870	4,487,245
Current liabilities
Accounts payable	161,657	189,811
Current portion of long-term debt	175,000	87,000
Accrued liabilities	24,895	31,290
Interest payable	19,836	19,933
Total current liabilities	381,388	328,034
Long-term debt, net	1,045,495	1,133,025
Deferred income taxes	754,108	702,104
Asset retirement obligations	79,351	71,598
Postretirement benefits	33,506	32,713
Other liabilities	68,043	68,284
Total liabilities	2,361,891	2,335,758
Commitments and contingencies
Stockholders' equity
Common stock	47,754	47,688
Additional paid-in capital	1,792,531	1,782,427
Retained earnings	2,147,822	2,143,213
Accumulated other comprehensive income	1,073	1,360
Treasury stock	(1,823,201)	(1,823,201)
Total stockholders' equity	2,165,979	2,151,487
Total liabilities and stockholders' equity	$ 4,527,870	$ 4,487,245