CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating Revenues:
Total operating revenues	$ 527	$ 636	$ 1,529	$ 2,293
Operating Costs and Expenses:
Operating expenses	202	189	577	523
General and administrative expenses	31	42	89	119
Montage acquisition-related expenses	3	0	3	0
Restructuring charges	0	4	12	9
Loss on sale of operating assets	0	0	0	3
Depreciation, depletion and amortization	70	125	267	352
Impairments	361	2	2,495	8
Taxes, other than income taxes	15	15	38	51
Total operating costs and expense	908	665	4,156	2,087
Operating Income (Loss)	(381)	(29)	(2,627)	206
Interest Expense:
Interest on debt	43	42	123	125
Other interest charges	2	2	7	5
Interest capitalized	(23)	(27)	(67)	(84)
Total Interest Expense	22	17	63	46
Gain (Loss) on Derivatives	(192)	100	38	220
Gain on Early Extinguishment of Debt	0	7	35	7
Other Income (Loss), Net	2	(2)	3	(7)
Income (Loss) Before Income Taxes	(593)	59	(2,614)	380
Provision (Benefit) for Income Taxes:
Current	0	(1)	(2)	(1)
Deferred	0	11	408	(400)
Total Provision (Benefit) from Income Taxes	0	10	406	(401)
Net Income (Loss)	$ (593)	$ 49	$ (3,020)	$ 781
Earnings (Loss) Per Common Share:
Basic (in dollars per share)	$ (1.04)	$ 0.09	$ (5.48)	$ 1.45
Diluted (in dollars per share)	$ (1.04)	$ 0.09	$ (5.48)	$ 1.44
Weighted Average Common Shares Outstanding:
Basic (in shares)	571,872,413	539,221,101	551,162,559	539,315,170
Diluted (in shares)	571,872,413	540,038,187	551,162,559	540,442,649
Gas sales
Operating Revenues:
Total operating revenues	$ 199	$ 238	$ 611	$ 943
Oil sales
Operating Revenues:
Total operating revenues	40	67	111	153
NGL sales
Operating Revenues:
Total operating revenues	68	52	158	191
Marketing
Operating Revenues:
Total operating revenues	219	279	645	1,004
Other
Operating Revenues:
Total operating revenues	1	0	4	2
Marketing purchases
Operating Costs and Expenses:
Marketing purchases	$ 226	$ 288	$ 675	$ 1,022