CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
OPERATING REVENUES:
Total operating revenues	$ 126	$ 139	$ 270	$ 297
OPERATING EXPENSES:
Operating and maintenance	39	49	89	96
General and administrative	9	8	19	14
Depreciation and amortization	26	30	52	59
Total operating expenses	74	87	160	169
OPERATING INCOME	52	52	110	128
OTHER INCOME (EXPENSE):
Interest expense, net	(3)	(5)	(7)	(10)
Interest expense — related company	(8)	(5)	(17)	(9)
Other, net	3	0	(4)	0
INCOME BEFORE INCOME TAX EXPENSE	44	42	82	109
Income tax expense	1	11	(1)	28
NET INCOME	43	31	83	81
OTHER COMPREHENSIVE INCOME, NET OF TAX
Actuarial gain relating to postretirement benefit plans	4	3	9	9
COMPREHENSIVE INCOME	47	34	92	90
Natural Gas, US Regulated [Member]
OPERATING REVENUES:
Transportation and storage of natural gas	122	133	261	285
Product and Service, Other [Member]
OPERATING REVENUES:
Transportation and storage of natural gas	$ 4	$ 6	$ 9	$ 12