Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues
Oil, Gas and NGL Sales	$ 3,043	$ 4,931	$ 4,809
Income from Equity Method Investees	90	170	206
Total Revenues	3,133	5,101	5,015
Costs and Expenses
Production Expense	962	947	844
Exploration Expense	488	498	415
Depreciation, Depletion and Amortization	2,131	1,759	1,568
General and Administrative	396	503	433
Asset Impairments	533	500	86
Goodwill Impairment	779	0	0
Other Operating (Income) Expense, Net	316	(24)	13
Total Operating Expenses	5,605	4,183	3,359
Operating Income (Loss)	(2,472)	918	1,656
Other (Income) Expense
(Gain) Loss on Commodity Derivative Instruments	(501)	(976)	133
Interest, Net of Amount Capitalized	263	210	158
Other Non-Operating (Income) Expense, Net	(15)	(26)	21
Total Other (Income) Expense	(253)	(792)	312
Income (Loss) from Continuing Operations Before Income Taxes	(2,219)	1,710	1,344
Income Tax Provision	222	496	437
Income (Loss) from Continuing Operations	(2,441)	1,214	907
Discontinued Operations, Net of Tax	0	0	71
Net Income (Loss)	$ (2,441)	$ 1,214	$ 978
Earnings (Loss) Per Share, Basic
Income (loss) from Continuing Operations (in dollars per share)	$ (6.07)	$ 3.36	$ 2.53
Discontinued Operations, Net of Tax (in dollars per share)	0.00	0.00	0.19
Net Income (in dollars per share)	(6.07)	3.36	2.72
Earnings (Loss) Per Share, Diluted
Income (loss) from Continuing Operations (in dollars per share)	(6.07)	3.27	2.50
Discontinued Operations, Net of Tax (in dollars per share)	0.00	0.00	0.19
Net Income (in dollars per share)	$ (6.07)	$ 3.27	$ 2.69
Weighted Average Number of Shares Outstanding, Basic (in shares)	402	361	359
Weighted Average Number of Shares Outstanding, Diluted (in shares)	402	367	363