Condensed Consolidated Statement of Equity (Deficit) - USD ($) $ in Millions	Total	Common Stock [Member]	Paid-in Capital [Member]	Notes Receivable From Parent [Member]	Accumulated Other Comprehensive Income [Member]	Accumulated Deficit [Member]
Balance at Dec. 31, 2019	$ 1,075	$ 0	$ 1,165	$ 0	$ (1)	$ (89)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss) Attributable to Parent	(195)
Net income (loss)	(195)	0	0	0	0	(195)
Employee Benefits and Share-based Compensation	13	0	13	0	0	0
Other comprehensive income	(48)	0	0	0	(48)	0
Return of Capital from parent	(10)	0	(10)	0	0	0
Disbursement of affiliate loan	(10)	0	0	(10)	0	0
Settlement of affiliate loan	10	0	0	10	0	0
Balance at Sep. 30, 2020	835	0	1,168	0	(49)	(284)
Balance at Jun. 30, 2020	919	0	1,164	0	(55)	(190)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss) Attributable to Parent	(94)
Net income (loss)	(94)	0	0	0	0	(94)
Employee Benefits and Share-based Compensation	4	0		0	0	0
Other comprehensive income	6	0	0	0	6	0
Balance at Sep. 30, 2020	835	0	1,168	0	(49)	(284)
Balance at Dec. 31, 2020	823	0	1,169	0	(27)	(319)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss) Attributable to Parent	98
Net income (loss)	98	0	0	0	0	98
Employee Benefits and Share-based Compensation	23	0	23	0	0	0
Other comprehensive income	(17)	0	0	0	(17)	0
Return of Capital from parent	0
Balance at Sep. 30, 2021	927	0	1,192	0	(44)	(221)
Balance at Jun. 30, 2021	883	0	1,184	0	(31)	(270)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss) Attributable to Parent	49
Net income (loss)	49	0	0	0	0	49
Employee Benefits and Share-based Compensation	8	0	8	0	0	0
Other comprehensive income	(13)	0	0	0	(13)	0
Balance at Sep. 30, 2021	$ 927	$ 0	$ 1,192	$ 0	$ (44)	$ (221)