Consolidated Statements of Operations (unaudited) - USD ($) shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues
Oil, Gas and NGL Sales		$ 765	$ 1,228	$ 2,227	$ 3,893
Income from Equity Method Investees		36	41	60	138
Total		801	1,269	2,287	4,031
Costs and Expenses
Production Expense		235	216	693	689
Exploration Expense		203	217	308	350
Depreciation, Depletion and Amortization		539	460	1,444	1,297
General and Administrative		109	132	308	399
Asset Impairments		0	33	43	164
Other Operating (Income) Expense, Net		182	(19)	252	(31)
Total		1,268	1,039	3,048	2,868
Operating Income (Loss)		(467)	230	(761)	1,163
Other (Income) Expense
Gain on Commodity Derivative Instruments		(267)	(385)	(331)	(74)
Interest, Net of Amount Capitalized		71	52	183	151
Other Non-Operating (Income) Expense, Net		(12)	(13)	(20)	1
Total		(208)	(346)	(168)	78
Income (Loss) Before Income Taxes		(259)	576	(593)	1,085
Income Tax (Benefit) Provision		24	157	(180)	274
Net Income (Loss)		$ (283)	$ 419	$ (413)	$ 811
Earnings Per Share, Basic [Abstract]
Net Income (in dollars per share)		$ (0.67)	$ 1.16	$ (1.05)	$ 2.25
Earnings Per Share, Diluted [Abstract]
Net Income (in dollars per share)		$ (0.67)	$ 1.12	$ (1.05)	$ 2.21
Weighted Average Number of Shares Outstanding [Abstract]
Weighted Average Number of Shares Outstanding, Basic (in shares)	[1]	420	362	392	361
Weighted Average Number of Shares Outstanding, Diluted (in shares)		420	367	392	367

[1] The weighted average number of shares outstanding includes the weighted average shares of common stock issued in connection with the underwritten public offering of 24.15 million shares of Noble Energy common stock in first quarter 2015 and issued in connection with the exchange of approximately 41 million shares for all outstanding shares of Rosetta common stock on July 20, 2015.