CONDENSED CONSOLIDATED BALANCE SHEET (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 510,256	$ 498,542
Accounts receivable, net	161,690	191,045
Income taxes receivable	26,963	10,298
Inventories	12,997	13,304
Other current assets	6,123	2,692
Total current assets	718,029	715,881
Properties and equipment, net (Successful efforts method)	4,234,772	4,250,125
Equity method investments	148,920	129,524
Other assets	27,045	27,039
TOTAL ASSETS	5,128,766	5,122,569
Current liabilities
Accounts payable	160,789	168,411
Current portion of long-term debt	237,000	0
Accrued liabilities	27,314	21,492
Interest payable	12,331	27,650
Derivative instruments	800	40,259
Total current liabilities	438,234	257,812
Long-term debt, net	1,284,551	1,520,530
Deferred income taxes	638,014	579,447
Asset retirement obligations	59,605	131,733
Postretirement benefits	27,360	36,259
Other liabilities	36,408	29,121
Total liabilities	2,484,172	2,554,902
Commitments and contingencies
Stockholders' equity
Common stock: Authorized - 960,000,000 shares of $0.10 par value in 2017 and 2016 Issued - 475,443,335 shares and 475,042,692 shares in 2017 and 2016, respectively	47,544	47,504
Additional paid-in capital	1,738,656	1,727,310
Retained earnings	1,230,002	1,098,703
Accumulated other comprehensive income	3,482	985
Less treasury stock, at cost: 12,935,926 and 9,892,680 shares in 2017 and 2016, respectively	(375,090)	(306,835)
Total stockholders' equity	2,644,594	2,567,667
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 5,128,766	$ 5,122,569

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).