Organization and Basis of Presentation (Details 3) - USD ($) $ / shares in Units, shares in Millions, $ in Millions			3 Months Ended								12 Months Ended
		Jan. 31, 2018	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Amount of beneficial conversion		$ 296									$ 0	$ 296	$ 0
EPS of Common Stock
Income (loss) from continuing operations			$ (181)	$ 389	$ 341	$ 355	$ 134	$ 399	$ 308	$ 181	904	1,022	(289)
Less: Preferred dividends											(3)	(71)	0
Less: Amortization of beneficial conversion feature											0	(296)	0
Less: Undistributed earnings allocated to preferred shareholders											(1)	0	0
Income from continuing operations available to common stockholders											900	655	(289)
Discontinued operations, net of tax	[1]										8	326	(1,435)
Less: Undistributed earnings allocated to preferred shareholders											0	0	0
Income (loss) from discontinued operations available to common stockholders											8	326	(1,435)
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON STOCKHOLDERS			$ (111)	$ 391	$ 308	$ 315	$ 128	$ (512)	$ 134	$ 1,213	908	981	(1,724)
Income allocated to preferred shareholders, preferred dilutive											4
Income (loss) attributable to common stockholders, dilutive											$ 912	$ 981	$ (1,724)
Share Count information:
Weighted average number of basic shares outstanding (in shares)											535	492	444
Assumed exercise of dilutive stock options and awards (in shares)											3	2	0
Assumed conversion of preferred stock (in shares)											4	0	0
Weighted average number of diluted shares outstanding (in shares)											542	494	444
Income (loss) available to common stockholders, per common share:
Income from continuing operations, basic (in dollars per share)			$ (0.33)	$ 0.72	$ 0.63	$ 0.66	$ 0.24	$ 0.68	$ 0.30	$ 0.05	$ 1.69	$ 1.33	$ (0.65)
Discontinued operations, basic (in dollars per share)			0.13	0.01	(0.05)	(0.07)	0.01	(1.70)	(0.02)	2.50	0.01	0.66	(3.23)
Basic - Net Income (Loss) Attributable to Common Stockholders (in dollars per share)			(0.20)	0.73	0.58	0.59	0.25	(1.02)	0.28	2.55	1.70	1.99	(3.88)
Income from continuing operations, diluted (in dollars per share)			(0.33)	0.72	0.63	0.66	0.24	0.68	0.30	0.05	1.67	1.33	(0.65)
Discontinued operations, diluted (in dollars per share)			0.13	0	(0.05)	(0.07)	0.01	(1.70)	(0.02)	2.49	0.01	0.66	(3.23)
Diluted - Net Income (Loss) Attributable to Common Stockholders (in dollars per share)			$ (0.20)	$ 0.72	$ 0.58	$ 0.59	$ 0.25	$ (1.02)	$ 0.28	$ 2.54	$ 1.68	$ 1.99	$ (3.88)
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of EPS (in shares)											0	1	3
Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of EPS (in shares)											26

[1] Net of income tax benefit of $5 million, $1,251 million, and $820 million in 2019, 2018 and 2017, respectively.