Condensed Consolidated Statements of Shareholders' Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjustment	AOCI Attributable to Parent [Member]	Parent [Member]	Parent [Member] Cumulative Effect, Period of Adoption, Adjustment
Balance at period start at Dec. 31, 2018		$ 2	$ 3,878	$ (233)	$ (8)	$ (425)	$ 3,222	$ (8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends, Preferred Stock				(7)			(7)
Proceeds, Issuance of Shares, Share-based Payment Arrangement, Including Option Exercised			8				8
Net income (loss)	$ (1,353)			(1,353)		0	(1,353)
Other Comprehensive Income (Loss), Net of Tax	6			0		6	6
Comprehensive Income (Loss), Net	(1,347)			(1,353)		6	(1,347)
Balance at period end at Sep. 30, 2019		2	3,886	(1,601)		(419)	1,868
Balance at period start at Jun. 30, 2019		2	3,886	(1,583)		(404)	1,901
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends, Preferred Stock				(2)			(2)
Net income (loss)	(16)			(16)			(16)
Other Comprehensive Income (Loss), Net of Tax	(15)					(15)	(15)
Comprehensive Income (Loss), Net	(31)			(16)		(15)	(31)
Balance at period end at Sep. 30, 2019		2	3,886	(1,601)		(419)	1,868
Balance at period start at Dec. 31, 2019	1,300	2	3,890	(2,185)		(407)	1,300
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends, Preferred Stock				(7)			(7)
Proceeds, Issuance of Shares, Share-based Payment Arrangement, Including Option Exercised			11				11
Net income (loss)	(107)			(107)			(107)
Other Comprehensive Income (Loss), Net of Tax	(14)					(14)	(14)
Comprehensive Income (Loss), Net	(121)			(107)		(14)	(121)
Balance at period end at Sep. 30, 2020	1,183	2	3,901	(2,299)		(421)	1,183
Balance at period start at Jun. 30, 2020		2	3,896	(2,290)		(433)	1,175
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends, Preferred Stock				(2)			(2)
Proceeds, Issuance of Shares, Share-based Payment Arrangement, Including Option Exercised			5				5
Net income (loss)	(7)			(7)			(7)
Other Comprehensive Income (Loss), Net of Tax	12					12	12
Comprehensive Income (Loss), Net	5			(7)		12	5
Balance at period end at Sep. 30, 2020	$ 1,183	$ 2	$ 3,901	$ (2,299)		$ (421)	$ 1,183