CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2017
Operating Revenues:
Operating Revenues	$ 3,038	$ 3,862		$ 3,203
Operating Costs and Expenses:
Operating expenses	720	785		671
General and administrative expenses	166	209		233
(Gain) loss on sale of operating assets, net	2	(17)		(6)
Restructuring charges	11	39		0
Depreciation, depletion and amortization	471	560		504
Impairments	16	171		0
Taxes, other than income taxes	62	89		94
Total Operating Costs and Expenses	2,768	3,065		2,472
Operating Income	270	797		731
Interest Expense:
Interest on debt	166	231		239
Other interest charges	8	8		9
Interest capitalized	(109)	(115)		(113)
Total Interest Expense	65	124		135
Gain (Loss) on Derivatives	274	(118)		422
Gain (Loss) on Early Extinguishment of Debt	8	(17)		(70)
Other Income (Loss), Net	(7)	0		5
Income (Loss) Before Income Taxes	480	538		953
Provision (Benefit) for Income Taxes:
Current	(2)	1		(22)
Deferred	(409)	0		(71)
Provision (benefit) for income taxes	(411)	1		(93)
Net Income (Loss)	891	537	[1]	1,046	[1]
Mandatory convertible preferred stock dividend	0	0		108
Participating securities - mandatory convertible preferred stock	0	2		123
Net Income (Loss) Attributable to Common Stock	$ 891	$ 535		$ 815
Earnings Per Common Share
Basic (in dollars per share)	$ 1.65	$ 0.93		$ 1.64
Diluted (in dollars per share)	$ 1.65	$ 0.93		$ 1.63
Weighted Average Common Shares Outstanding:
Basic (in shares)	539,345,343	574,631,756		498,264,321
Diluted (in shares)	540,382,914	576,642,808		500,804,297
Gas sales
Operating Revenues:
Operating Revenues	$ 1,241	$ 1,998		$ 1,793
Oil sales
Operating Revenues:
Operating Revenues	223	196		102
NGL sales
Operating Revenues:
Operating Revenues	274	352		206
Marketing
Operating Revenues:
Operating Revenues	1,297	1,222		972
Gas gathering
Operating Revenues:
Operating Revenues	0	89		126
Other
Operating Revenues:
Operating Revenues	3	5		4
Marketing purchases
Operating Costs and Expenses:
Marketing purchases	$ 1,320	$ 1,229		$ 976

[1] In 2018 and 2017, deferred tax activity incurred in other comprehensive income was offset by a valuation allowance.