Earnings Per Share Of Common Stock (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions			3 Months Ended		9 Months Ended
		Jan. 31, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share [Abstract]
Amount of beneficial conversion		$ 296			$ 296	$ 0
EPS of Common Stock
Income from continuing operations			$ 387	$ 301	840	772
Less: Preferred dividends			(19)	0	(61)	0
Less: Amortization of beneficial conversion feature			(35)	0	(296)	0
Less: Undistributed earnings allocated to preferred shareholders			0	0	0	0
Income from continuing operations available to common stockholders			333	301	483	772
Discontinued operations, net of tax	[1]		(845)	95	370	3
Less: Undistributed earnings allocated to preferred shareholders			0	0	0	0
Income (loss) from discontinued operations available to common stockholders			(845)	95	370	3
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON STOCKHOLDERS			$ (512)	$ 396	$ 853	$ 775
Share Count information:
Weighted average number of basic shares outstanding (in shares)			503	444	485	444
Assumed exercise of dilutive stock options and awards (in shares)			2	2	2	1
Weighted average number of diluted shares outstanding			505	446	487	445
Income (loss) available to common stockholders, per common share:
Income from continuing operations, basic (in dollars per share)			$ 0.66	$ 0.68	$ 1.00	$ 1.74
Discontinued operations, basic (in dollars per share)			(1.68)	0.21	0.76	0.01
Basic - Net Income Attributable to Common Stockholders (in dollars per share)			(1.02)	0.89	1.76	1.75
Income from continuing operations, diluted (in dollars per share)			0.66	0.68	0.99	1.73
Discontinued operations, diluted (in dollars per share)			(1.68)	0.21	0.76	0.01
Diluted - Net Income Attributable to Common Stockholders (in dollars per share)			$ (1.02)	$ 0.89	$ 1.75	$ 1.74
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the calculation of diluted shares outstanding, in shares			1	1	1	1
Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the calculation of diluted shares outstanding, in shares			26

[1] Net of income tax expense (benefit) of $(354) million and $37 million for the three months ended September 30, 2018 and 2017, respectively, and income tax benefits of $(1.3) billion and $(1) million for the nine months ended September 30, 2018 and 2017, respectively.