CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Document Fiscal Year Focus					2020
OPERATING REVENUES
Transmission and other services	$ 341		$ 288		$ 630	$ 577
Formula rate true-up	1		32		34	50
Total operating revenues	342		320		664	627
OPERATING EXPENSES
Operation and maintenance	20		32		47	57
General and administrative	28		38		59	76
Depreciation and amortization	54		51		108	98
Taxes other than income taxes	31		28		62	59
Total operating expenses	133		149		276	290
OPERATING INCOME	209		171		388	337
OTHER EXPENSES (INCOME)
Interest expense, net	57		64		116	123
Allowance for equity funds used during construction	(6)		(8)		(12)	(16)
Other (income) and expenses, net	3		1		1	1
Total other expenses (income)	48		55		103	106
INCOME BEFORE INCOME TAXES	161		116		285	231
INCOME TAX PROVISION	40		29		72	60
NET INCOME	121	$ 92	87	$ 84	213	171
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(1)		1		(17)	1
Total other comprehensive income, net of tax	(1)	$ (16)	1		(17)	1
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 120		$ 88		$ 196	$ 172