CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
OPERATING REVENUES:
Total operating revenues	$ 574	$ 480		$ 514
Cost of Goods and Services Sold	4	3		2
OPERATING EXPENSES:
Operating, maintenance and general	215	199		209
General and Administrative Expense	30	28		31
Depreciation and amortization	122	127		130
Asset Impairment Charges	0	389		771
Total operating expenses	371	746		1,143
Operating Income (Loss)	203	(266)	[1]	(629)
OTHER INCOME (EXPENSE):
Interest expense, net	(28)	(46)		(49)
Income from unconsolidated affiliates	(13)	0		0
Interest income — affiliates	0	10		26
Other, net	(5)	(6)		(7)
Total other expenses, net	(46)	(42)		(30)
Income (Loss) from Continuing Operations Before Income Tax Expense	157	(308)		(659)
Income tax expense (benefit)	49	(263)		(13)
Net Income (Loss)	108	(45)		(646)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax	(42)	(10)		3
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax	0	2		0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	66	(53)		(643)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	11	3		0
Natural Gas, Midstream [Member]
Income Statement
Revenue from Contract with Customer, Including Assessed Tax	544	460		494
Product and Service, Other [Member]
Income Statement
Revenue from Contract with Customer, Including Assessed Tax	$ 30	$ 20		$ 20

[1] Operating income (loss) includes $389 million of impairment losses recognized during the fourth quarter of 2017.