Consolidated Condensed Statements of Capital (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Beginning balance	$ 3,401	$ 3,054	$ 3,303	$ 2,978
Net income	107	85	171	148
Other comprehensive income, after tax		1		1
Equity contributions from Parent	110	105	220	215
Dividends to Parent	(64)	(63)	(140)	(160)
Ending balance	3,554	3,182	3,554	3,182
Common Stock [Member]
Beginning balance	$ 3,100	$ 2,755	$ 2,990	$ 2,645
Beginning balance	10	10	10	10
Equity contributions from Parent	$ 110	$ 105	$ 220	$ 215
Ending balance	$ 3,210	$ 2,860	$ 3,210	$ 2,860
Ending balance	10	10	10	10
Retained Earnings [Member]
Beginning balance	$ 302	$ 301	$ 314	$ 335
Net income	107	85	171	148
Dividends to Parent	(64)	(63)	(140)	(160)
Ending balance	345	323	345	323
Accumulated Other Comprehensive Loss [Member]
Beginning balance	(1)	(2)	(1)	(2)
Other comprehensive income, after tax		1		1
Ending balance	$ (1)	$ (1)	$ (1)	$ (1)