Consolidated Condensed Statements of Capital (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Beginning balance	$ 4,375	$ 3,845	$ 4,216	$ 3,695
Net income	121	117	213	194
Equity contributions from Parent	135	120	290	265
Dividends to Parent	(93)	(77)	(181)	(150)
Other		(2)		(1)
Ending balance	4,538	4,003	4,538	4,003
Common Stock [Member]
Beginning balance	$ 4,045	$ 3,530	$ 3,890	$ 3,385
Beginning balance	10	10	10	10
Equity contributions from Parent	$ 135	$ 120	$ 290	$ 265
Ending balance	$ 4,180	$ 3,650	$ 4,180	$ 3,650
Ending balance	10	10	10	10
Retained Earnings [Member]
Beginning balance	$ 331	$ 316	$ 327	$ 311
Net income	121	117	213	194
Dividends to Parent	(93)	(77)	(181)	(150)
Other		(2)		(1)
Ending balance	359	354	359	354
Accumulated Other Comprehensive Loss [Member]
Beginning balance	(1)	(1)	(1)	(1)
Ending balance	$ (1)	$ (1)	$ (1)	$ (1)