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, 2018	$ 4,315	$ 2,860	$ 1,279	$ (3)	$ 179
Beginning balance (in shares) at Dec. 31, 2018		40
Cumulative-effect of change in accounting principle	0		1	(1)
Total comprehensive income (loss) available (attributable) to common shareholder	(1,103)		(1,109)		6
Capital contribution from parent	675	$ 675
Dividend to parent	(20)		(20)
Ending balance at Mar. 31, 2019	3,867	$ 3,535	151	(4)	185
Ending balance (in shares) at Mar. 31, 2019		40
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