CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
OPERATING REVENUES:
Total operating revenues	$ 158	$ 149
OPERATING EXPENSES:
Cost of natural gas and other energy	0	1
Operating and maintenance	47	47
General and administrative	6	7
Depreciation and amortization	29	30
Total operating expenses	82	85
OPERATING INCOME	76	64
OTHER INCOME (EXPENSE):
Interest expense, net	(5)	(10)
Interest Expense, Related Party	(4)	(1)
Other, net	0	(1)
INCOME BEFORE INCOME TAX EXPENSE	67	52
Income tax expense	17	18
NET INCOME	50	34
OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX
Actuarial income (loss) relating to postretirement benefit plans	6	(1)
COMPREHENSIVE INCOME	56	33
Natural Gas, US Regulated [Member]
OPERATING REVENUES:
Transportation and storage of natural gas	152	142
Product and Service, Other [Member]
OPERATING REVENUES:
Transportation and storage of natural gas	$ 6	$ 7