CONSOLIDATED STATEMENTS OF COMMON STOCKHOLDER'S EQUITY - USD ($) $ in Millions	Total	Common stock	Additional Paid In Capital	Retained Earnings
Balance (in shares) at Dec. 31, 2020		933,000
Beginning Balance at Dec. 31, 2020	$ 1,068	$ 93	$ 605	$ 370
Increase (Decrease) in Stockholder's Equity
Net income	82
Common dividends declared to parent	(83)			(83)
Contribution of capital by parent	36		36
Balance (in shares) at Sep. 30, 2021		933,000
Ending Balance at Sep. 30, 2021	1,103	$ 93	641	369
Balance (in shares) at Jun. 30, 2021		933,000
Beginning Balance at Jun. 30, 2021	1,113	$ 93	638	382
Increase (Decrease) in Stockholder's Equity
Net income	36			36
Common dividends declared to parent	(49)			(49)
Contribution of capital by parent	3		3
Balance (in shares) at Sep. 30, 2021		933,000
Ending Balance at Sep. 30, 2021	$ 1,103	$ 93	641	369
Balance (in shares) at Dec. 31, 2021	933,000	933,000
Beginning Balance at Dec. 31, 2021	$ 1,103	$ 93	642	368
Increase (Decrease) in Stockholder's Equity
Net income	102
Common dividends declared to parent	(64)			(64)
Contribution of capital by parent	$ 110		110
Balance (in shares) at Sep. 30, 2022	933,000	933,000
Ending Balance at Sep. 30, 2022	$ 1,251	$ 93	752	406
Balance (in shares) at Jun. 30, 2022		933,000
Beginning Balance at Jun. 30, 2022	1,184	$ 93	702	389
Increase (Decrease) in Stockholder's Equity
Net income	40			40
Common dividends declared to parent	(23)			(23)
Contribution of capital by parent	$ 50		50
Balance (in shares) at Sep. 30, 2022	933,000	933,000
Ending Balance at Sep. 30, 2022	$ 1,251	$ 93	$ 752	$ 406