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, 2021		933,000
Beginning Balance at Dec. 31, 2021	$ 1,103	$ 93	$ 642	$ 368
Increase (Decrease) in Stockholder's Equity
Net income	62
Common dividends declared to parent	(41)			(41)
Contribution of capital by parent	60		60
Balance (in shares) at Jun. 30, 2022		933,000
Ending Balance at Jun. 30, 2022	1,184	$ 93	702	389
Balance (in shares) at Mar. 31, 2022		933,000
Beginning Balance at Mar. 31, 2022	1,158	$ 93	672	393
Increase (Decrease) in Stockholder's Equity
Net income	15			15
Common dividends declared to parent	(19)			(19)
Contribution of capital by parent	30		30
Balance (in shares) at Jun. 30, 2022		933,000
Ending Balance at Jun. 30, 2022	$ 1,184	$ 93	702	389
Balance (in shares) at Dec. 31, 2022	933,000	933,000
Beginning Balance at Dec. 31, 2022	$ 1,259	$ 93	761	405
Increase (Decrease) in Stockholder's Equity
Net income	71
Common dividends declared to parent	(49)			(49)
Contribution of capital by parent	$ 45		45
Balance (in shares) at Jun. 30, 2023	933,000	933,000
Ending Balance at Jun. 30, 2023	$ 1,326	$ 93	806	427
Balance (in shares) at Mar. 31, 2023		933,000
Beginning Balance at Mar. 31, 2023	1,310	$ 93	791	426
Increase (Decrease) in Stockholder's Equity
Net income	26			26
Common dividends declared to parent	(25)			(25)
Contribution of capital by parent	$ 15		15
Balance (in shares) at Jun. 30, 2023	933,000	933,000
Ending Balance at Jun. 30, 2023	$ 1,326	$ 93	$ 806	$ 427