STATEMENTS OF COMMON STOCKHOLDER'S EQUITY - USD ($) $ in Millions	Total	Common stock	Additional Paid In Capital	Retained Earnings	AOCI Attributable to Parent
Beginning Balance (in shares) at Dec. 31, 2017		100
Beginning Balance at Dec. 31, 2017	$ 2,130	$ 0	$ 1,590	$ 541	$ (1)
Increase (Decrease) in Stockholder's Equity
Net Income (Loss) Attributable to Parent	213			213
Common dividends declared to parent	(148)			(148)
Contribution of capital by parent	342		342
Ending Balance (in shares) at Dec. 31, 2018		100
Ending Balance at Dec. 31, 2018	2,537	$ 0	1,932	606	(1)
Increase (Decrease) in Stockholder's Equity
Net Income (Loss) Attributable to Parent	263			263
Common dividends declared to parent	(334)			(334)
Contribution of capital by parent	$ 419		419
Ending Balance (in shares) at Dec. 31, 2019	100	100
Ending Balance at Dec. 31, 2019	$ 2,885	$ 0	2,351	535	(1)
Increase (Decrease) in Stockholder's Equity
Net Income (Loss) Attributable to Parent	295			295
Common dividends declared to parent	(321)			(321)
Contribution of capital by parent	$ 439		439
Ending Balance (in shares) at Dec. 31, 2020	100	100
Ending Balance at Dec. 31, 2020	$ 3,298	$ 0	$ 2,790	$ 509	$ (1)