CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Current assets
Cash and cash equivalents	$ 28	$ 22
Accounts receivable
Customer, net of allowance of $1 in 2015 and less than $1 in 2014	209	234
Other, net of allowance of $1 in 2015 and 2014	18	38
Income tax receivable	1	24
Materials and supplies	25	25
Derivative instruments	672	752
Prepaid assets	8	7
Total current assets	961	1,102
Property, plant and equipment, at cost
Oil and natural gas properties	11,359	10,241
Other property, plant and equipment	81	76
Total property, plant and equipment, at cost	11,440	10,317
Less accumulated depreciation, depletion and amortization	2,316	1,589
Total property, plant and equipment, net	9,124	8,728
Other assets
Derivative instruments	181	297
Unamortized debt issue costs	84	90
Other	2	2
Total other assets	267	389
Total assets	10,352	10,219
Accounts payable
Trade	102	142
Other	213	403
Deferred income taxes	233	251
Derivative instruments	1	1
Accrued interest	102	53
Asset retirement obligations	1	2
Other accrued liabilities	48	47
Total current liabilities	700	899
Long-term debt	4,931	4,598
Other long-term liabilities
Deferred income taxes	331	327
Asset retirement obligations	39	40
Other	6	7
Total non-current liabilities	$ 5,307	$ 4,972
Commitments and contingencies
Stockholders’ equity
Preferred stock, $0.01 par value; 50 million shares authorized; no shares issued or outstanding	$ 0	$ 0
Additional paid-in capital	3,524	3,510
Retained earnings	819	836
Total stockholders’ equity	4,345	4,348
Total liabilities and equity	10,352	10,219
Class A
Stockholders’ equity
Common Stock	2	2
Total stockholders’ equity	2	2
Class B
Stockholders’ equity
Common Stock	0	0
Total stockholders’ equity	$ 0	$ 0