Consolidated Statements of Changes in Common Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Retained Earnings	AOCI	Non-controlling Interest
Beginning balance at Dec. 31, 2020	$ 4,484	$ 4,017	$ 277	$ (2)	$ 192
Beginning balance (in shares) at Dec. 31, 2020		40
Total comprehensive income available to common shareholder	230		208	1	21
Capital contribution from parent	149	$ 149
Return of capital to parent	(150)	(150)
Dividend to parent	(188)		(150)		(38)
Ending balance at Dec. 31, 2021	4,525	$ 4,016	335	(1)	175
Ending balance (in shares) at Dec. 31, 2021		40
Total comprehensive income available to common shareholder	502		483	(1)	20
Capital contribution from parent	72	$ 72
Dividend to parent	(433)		(400)		(33)
Ending balance at Dec. 31, 2022	4,666	$ 4,088	418	(2)	162
Ending balance (in shares) at Dec. 31, 2022		40
Total comprehensive income available to common shareholder	396		374	1	21
Dividend to parent	(200)		(200)
Ending balance at Dec. 31, 2023	$ 4,862	$ 4,088	$ 592	$ (1)	$ 183
Ending balance (in shares) at Dec. 31, 2023		40