CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
OPERATING REVENUES:
Total operating revenues	$ 547	$ 578	$ 574
Cost of Goods and Services Sold	0	0	4
OPERATING EXPENSES:
Operating, maintenance and general	177	193	215
General and Administrative Expense	37	30	30
Depreciation and amortization	116	112	122
Asset Impairment Charges	0	12	0
Total operating expenses	330	347	371
Operating Income (Loss)	217	231	203
OTHER EXPENSE:
Interest expense, net	(14)	(17)	(28)
Income from unconsolidated affiliates	(32)	(25)	(13)
Other, net	(3)	(2)	(5)
Total other expenses, net	(49)	(44)	(46)
Income (Loss) from Continuing Operations Before Income Tax Expense	168	187	157
Income tax expense (benefit)	(3)	(402)	49
Net Income (Loss)	171	589	108
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax	21	23	(42)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	192	612	66
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	0	4	11
Natural Gas, Midstream [Member]
Income Statement
Revenue from Contract with Customer, Including Assessed Tax	528	556	544
Product and Service, Other [Member]
Income Statement
Revenue from Contract with Customer, Including Assessed Tax	$ 19	$ 22	$ 30