CONSOLIDATED STATEMENTS OF COMMON STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Millions	Total	Common Stock	Additional Paid In Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2019		100
Beginning balance at Dec. 31, 2019	$ 2,885	$ 0	$ 2,351	$ 535	$ (1)
Increase (Decrease) in Stockholders' Equity
Net income	114			114
Dividends declared to parent	(130)			(130)
Contributions of capital by parent	436		436
Ending balance (in shares) at Jun. 30, 2020		100
Ending balance at Jun. 30, 2020	3,305	$ 0	2,787	519	(1)
Beginning balance (in shares) at Mar. 31, 2020		100
Beginning balance at Mar. 31, 2020	2,884	$ 0	2,383	502	(1)
Increase (Decrease) in Stockholders' Equity
Net income	72			72
Dividends declared to parent	(55)			(55)
Contributions of capital by parent	404		404
Ending balance (in shares) at Jun. 30, 2020		100
Ending balance at Jun. 30, 2020	$ 3,305	$ 0	2,787	519	(1)
Beginning balance (in shares) at Dec. 31, 2020	100	100
Beginning balance at Dec. 31, 2020	$ 3,298	$ 0	2,790	509	(1)
Increase (Decrease) in Stockholders' Equity
Net income	126			126
Dividends declared to parent	(131)			(131)
Contributions of capital by parent	$ 304		304
Ending balance (in shares) at Jun. 30, 2021	100	100
Ending balance at Jun. 30, 2021	$ 3,597	$ 0	3,094	504	(1)
Beginning balance (in shares) at Mar. 31, 2021		100
Beginning balance at Mar. 31, 2021	3,608	$ 0	3,094	515	(1)
Increase (Decrease) in Stockholders' Equity
Net income	68			68
Dividends declared to parent	$ (79)			(79)
Ending balance (in shares) at Jun. 30, 2021	100	100
Ending balance at Jun. 30, 2021	$ 3,597	$ 0	$ 3,094	$ 504	$ (1)