Condensed Consolidated Statements of Shareholders' Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption | Accounting Standards Update 2014-09		$ 0	$ 0	$ (8)	$ 0	$ (8)
Balance at period start at Dec. 31, 2018		2	3,878	(233)	(425)	3,222
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividend, preferred stock		0	0	(2)	0	(2)
Proceeds, Issuance of Shares, Share-based Payment Arrangement, Including Option Exercised		0	1	0	0	1
Net income (loss)	$ (308)	0	0	(308)	0	(308)
Other Comprehensive Income (Loss), Net of Tax	22	0	0	0	22	22
Comprehensive Income (Loss), Net	(286)	0	0	(308)	22	(286)
Balance at period end at Mar. 31, 2019		2	3,879	(551)	(403)	2,927
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]
Cash dividend, preferred stock		0	0	(2)	0	(2)
Proceeds, Issuance of Shares, Share-based Payment Arrangement, Including Option Exercised		0	1	0	0	1
Net income (loss)	(49)	0	0	(49)	0	(49)
Other Comprehensive Income (Loss), Net of Tax	(30)	0	0	0	(30)	(30)
Comprehensive Income (Loss), Net	(79)	0	0	(49)	(30)	(79)
Balance at period end at Mar. 31, 2020	$ 1,220	$ 2	$ 3,891	$ (2,236)	$ (437)	$ 1,220