CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
OPERATING REVENUES:
Total operating revenues	$ 211	$ 144
OPERATING EXPENSES:
Operating and maintenance	40	50
General and administrative	9	10
Depreciation and amortization	26	26
Total operating expenses	75	86
OPERATING INCOME	136	58
OTHER INCOME (EXPENSE):
Interest expense, net	(4)	(4)
Interest expense — related company	(6)	(9)
Other, net	0	(7)
INCOME BEFORE INCOME TAX BENEFIT	126	38
Income tax expense	0	(2)
NET INCOME	126	40
OTHER COMPREHENSIVE INCOME, NET OF TAX
Actuarial gain relating to postretirement benefit plans	6	5
COMPREHENSIVE INCOME	132	45
Natural Gas, US Regulated [Member]
OPERATING REVENUES:
Transportation and storage of natural gas	206	139
Product and Service, Other [Member]
OPERATING REVENUES:
Transportation and storage of natural gas	$ 5	$ 5