Consolidated Statements of Changes in Common Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Retained Earnings	AOCI	Noncontrolling Interest
Beginning balance at Dec. 31, 2019	$ 3,892	$ 3,695	$ 20	$ (3)	$ 180
Beginning balance (in shares) at Dec. 31, 2019		40
Total comprehensive income (loss) available(attributable) to common shareholder	93		88		5
Ending balance at Mar. 31, 2020	3,985	$ 3,695	108	(3)	185
Ending balance (in shares) at Mar. 31, 2020		40
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 (loss) available(attributable) to common shareholder	55		51		4
Dividend to parent	(75)		(75)
Ending balance at Mar. 31, 2021	$ 4,464	$ 4,017	$ 253	$ (2)	$ 196
Ending balance (in shares) at Mar. 31, 2021		40