CONSOLIDATED STATEMENTS OF COMMON STOCKHOLDER'S EQUITY - USD ($) $ in Millions	Total	Common stock	Additional Paid In Capital	Retained Earnings	AOCI Attributable to Parent
Balance at beginning of period (shares) at Dec. 31, 2018		1,000,000
Balance at beginning of period at Dec. 31, 2018	$ 5,573	$ 0	$ 3,624	$ 1,972	$ (23)
Increase (Decrease) in Stockholder's Equity
Net income	543			543
Other comprehensive income	0
Dividends declared to parent	(479)			(479)
Contribution of capital by parent	444		444
Balance at end of period (shares) at Dec. 31, 2019		1,000,000
Balance at end of period at Dec. 31, 2019	6,081	$ 0	4,068	2,036	(23)
Increase (Decrease) in Stockholder's Equity
Net income	591			591
Other comprehensive income	1				1
Dividends declared to parent	(420)			(420)
Contribution of capital by parent	517		517
Adoption of ASC Topic 326	$ (1)			(1)
Balance at end of period (shares) at Dec. 31, 2020	1,000,000	1,000,000
Balance at end of period at Dec. 31, 2020	$ 6,769	$ 0	4,585	2,206	(22)
Increase (Decrease) in Stockholder's Equity
Net income	606			606
Other comprehensive income	2				2
Dividends declared to parent	(421)			(421)
Contribution of capital by parent	$ 617		617
Balance at end of period (shares) at Dec. 31, 2021	1,000,000	1,000,000
Balance at end of period at Dec. 31, 2021	$ 7,573	$ 0	$ 5,202	$ 2,391	$ (20)