CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 779,382	$ 405,862
Accounts receivable:
Trade, net of allowance	81,888	134,443
Oil and gas sales, net of allowance	136,537	259,220
Gas gathering, processing, and marketing, net of allowance	6,935	18,009
Other	38	436
Oil and gas well equipment and supplies	54,579	89,780
Deferred income taxes		13,475
Derivative instruments	10,745
Prepaid expenses	7,036	9,356
Other current assets	790	1,223
Total current assets	1,077,930	931,804
Oil and gas properties at cost, using the full cost method of accounting:
Proved properties	15,546,948	14,402,064
Unproved properties and properties under development, not being amortized	440,166	759,149
Gross oil and gas properties	15,987,114	15,161,213
Less - accumulated depreciation, depletion, amortization and impairment	(12,710,968)	(8,257,502)
Net oil and gas properties	3,276,146	6,903,711
Fixed assets, less accumulated depreciation of $207,173 and $175,453	230,009	211,031
Goodwill	620,232	620,232
Derivative instruments	501
Other assets, net	38,468	41,691
Total assets	5,243,286	8,708,469
Accounts payable:
Trade	53,384	102,276
Gas gathering, processing, and marketing	13,431	35,775
Accrued liabilities:
Exploration and development	56,721	200,929
Taxes other than income	17,545	26,950
Other	173,242	219,505
Revenue payable	95,744	190,892
Total current liabilities	410,067	776,327
Long-term debt:
Principal	1,500,000	1,500,000
Less - unamortized debt issuance costs	(14,380)	(16,824)
Long-term debt, net	1,485,620	1,483,176
Deferred income taxes	352,705	1,754,706
Asset retirement obligation	153,857	159,792
Other liabilities	43,359	33,836
Total liabilities	2,445,608	4,207,837
Stockholders' equity:
Common stock, $0.01 par value, 200,000,000 shares authorized, 94,820,570 and 87,592,535 shares issued, respectively	948	876
Paid-in capital	2,762,976	1,997,080
Retained earnings	33,313	2,501,574
Accumulated other comprehensive income	441	1,102
Total stockholders' equity	2,797,678	4,500,632
Total liabilities and stockholders' equity	$ 5,243,286	$ 8,708,469