CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
OPERATING REVENUES:
Total operating revenues	$ 139	$ 134	$ 297	$ 283
OPERATING EXPENSES:
Cost of natural gas and other energy	0	1	0	2
Operating and maintenance	49	54	96	101
General and administrative	8	7	14	14
Depreciation and amortization	30	30	59	60
Total operating expenses	87	92	169	177
OPERATING INCOME	52	42	128	106
OTHER INCOME (EXPENSE):
Interest expense, net	(5)	(8)	(10)	(18)
Interest Expense, Related Party	(5)	(2)	(9)	(3)
Other, net	0	(1)	0	(2)
INCOME BEFORE INCOME TAX EXPENSE	42	31	109	83
Income tax expense	11	9	28	27
NET INCOME	31	22	81	56
OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX
Actuarial income (loss) relating to postretirement benefit plans	3	0	9	(1)
COMPREHENSIVE INCOME	34	22	90	55
Natural Gas, US Regulated [Member]
OPERATING REVENUES:
Transportation and storage of natural gas	133	131	285	273
Product and Service, Other [Member]
OPERATING REVENUES:
Transportation and storage of natural gas	$ 6	$ 3	$ 12	$ 10