CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash Flows From Operating Activities
Net income (loss)	$ 924	$ 704	$ (707)
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	942	787	811
Amortization of debt issuance cost	10	4	4
Impairment of natural gas and oil properties			1,940
Deferred income taxes	504	497	(462)
(Gain) loss on derivatives, net of settlement	(130)	(21)	2
Stock-based compensation	18	13	12
Other	2	1
Change in assets and liabilities:
Accounts receivable	(66)	(86)	(36)
Inventories	1	(6)	18
Accounts payable	84	74	41
Taxes payable	24	5	22
Interest payable		(1)	5
Advances from partners		(69)	(15)
Other assets and liabilities	22	7	19
Net cash provided by operating activities	2,335	1,909	1,654
Cash Flows From Investing Activities
Capital investments	(2,043)	(2,157)	(2,108)
Acquisition of oil and gas properties	(5,298)	(96)
Proceeds from sale of property and equipment	43	18	201
Transfers to restricted cash		9	(168)
Transfers from restricted cash			159
Other	10	10	9
Net cash used in investing activities	(7,288)	(2,216)	(1,907)
Cash Flows From Financing Activities
Payments on current portion of long-term debt	(1)	(1)	(1)
Payments on revolving long-term debt	(5,179)	(3,148)	(2,264)
Borrowings under revolving long-term debt	5,196	3,430	1,592
Change in bank drafts outstanding	11	(7)	(36)
Proceeds from issuance of long-term debt	500		999
Proceeds from issuance of short-term debt	4,500
Debt issuance costs	(56)		(8)
Proceeds from exercise of common stock options	12	10	9
Other		(7)
Net cash provided by financing activities	4,983	277	291
Effect of exchange rate changes on cash		(1)
Increase (decrease) in cash and cash equivalents	30	(31)	38
Cash and cash equivalents at beginning of year	23	54	16
Cash and cash equivalents at end of period	$ 53	$ 23	$ 54