CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Revenues:
Operating revenues	$ 2,308	$ 3,038	$ 3,862
Operating Costs and Expenses:
Operating expenses	813	720	785
General and administrative expenses	121	166	209
Montage merger-related expenses	41	0	0
Restructuring charges	16	11	39
(Gain) loss on sale of operating assets	0	2	(17)
Depreciation, depletion and amortization	357	471	560
Impairments	2,830	16	171
Taxes, other than income taxes	55	62	89
Total Operating Costs and Expenses	5,179	2,768	3,065
Operating Income (Loss)	(2,871)	270	797
Interest Expense:
Interest on debt	171	166	231
Other interest charges	11	8	8
Interest capitalized	(88)	(109)	(115)
Total Interest Expense	94	65	124
Gain (Loss) on Derivatives	224	274	(118)
Gain (Loss) on Early Extinguishment of Debt	35	8	(17)
Other Income (Loss), Net	1	(7)	0
Income (Loss) Before Income Taxes	(2,705)	480	538
Provision (Benefit) for Income Taxes:
Current	(2)	(2)	1
Deferred	409	(409)	0
Provision (Benefit) for Income Taxes	407	(411)	1
Net Income (Loss)	(3,112)	891	537	[1]
Participating securities – mandatory convertible preferred stock	0	0	2
Net Income (Loss) Attributable to Common Stock	$ (3,112)	$ 891	$ 535
Earnings (Loss) Per Common Share
Basic (in dollars per share)	$ (5.42)	$ 1.65	$ 0.93
Diluted (in dollars per share)	$ (5.42)	$ 1.65	$ 0.93
Weighted Average Common Shares Outstanding:
Basic (in shares)	573,889,502	539,345,343	574,631,756
Diluted (in shares)	573,889,502	540,382,914	576,642,808
Gas sales
Operating Revenues:
Operating revenues	$ 967	$ 1,241	$ 1,998
Oil sales
Operating Revenues:
Operating revenues	154	223	196
NGL sales
Operating Revenues:
Operating revenues	265	274	352
Marketing
Operating Revenues:
Operating revenues	917	1,297	1,222
Gas gathering
Operating Revenues:
Operating revenues	0	0	89
Other
Operating Revenues:
Operating revenues	5	3	5
Marketing purchases
Operating Costs and Expenses:
Marketing purchases	$ 946	$ 1,320	$ 1,229

[1] In 2018, deferred tax activity incurred in other comprehensive income was offset by a valuation allowance.