Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016		Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 1,606		$ 2,812
Accrued production receivable	124,936		100,413
Trade and other receivables, net	43,900		87,093
Derivative assets	0		142,846
Other current assets	10,684		10,005
Total current assets	181,126		343,169
Oil and natural gas properties (using full cost accounting)
Proved properties	10,419,827		10,245,195
Unevaluated properties	927,819		894,948
CO2 properties	1,188,467		1,187,458
Pipelines and plants	2,285,812		2,293,219
Other property and equipment	378,776		408,194
Less accumulated depletion, depreciation, amortization and impairment	(11,212,327)		(9,653,205)
Net property and equipment	3,988,374		5,375,809
Other assets	105,078		166,555
Total assets	4,274,578		5,885,533
Current liabilities
Accounts payable and accrued liabilities	200,266		253,197
Oil and gas production payable	80,585		87,337
Derivative liabilities	69,279		0
Current maturities of long-term debt (including future interest payable of $50,349 and $0, respectively – see Note 4)	83,366	[1]	32,481
Total current liabilities	433,496		373,015
Long-term liabilities
Long-term debt, net of current portion (including future interest payable of $178,476 and $0, respectively – see Note 4)	2,909,732		3,245,114
Asset retirement obligations	146,807		138,919
Deferred tax liabilities, net	293,878		852,089
Other liabilities	22,217		27,484
Total long-term liabilities	3,372,634		4,263,606
Commitments and contingencies (Note 10)
Stockholders' equity
Preferred stock, $.001 par value, 25,000,000 shares authorized, none issued and outstanding	0		0
Common stock, $.001 par value, 600,000,000 shares authorized; 402,334,655 and 354,541,626 shares issued, respectively	402		355
Paid-in capital in excess of par	2,534,670		2,353,549
Accumulated deficit	(2,018,989)		(1,058,954)
Treasury stock, at cost, 3,906,877 and 3,124,311 shares, respectively	(47,635)		(46,038)
Total stockholders' equity	468,448		1,248,912
Total liabilities and stockholders' equity	$ 4,274,578		$ 5,885,533

[1] Future interest payable on our 9% Senior Secured Second Lien Notes due 2021 (the “2021 Senior Secured Notes”) represents most of the interest due over the term of this obligation, which has been accounted for as debt in accordance with FASC 470-60, Troubled Debt Restructuring by Debtors. Our current maturities of long-term debt as of December 31, 2016 include $50.3 million of future interest payable related to the 2021 Senior Secured Notes that is due within the next twelve months. See 2016 Senior Subordinated Notes Exchange below for further discussion.