Earnings Per Share Net Income for Earnings Per Share Calculations - Basic and Diluted (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ 483	$ (184)	$ 375	$ 299	$ (63)
Net Income Attributable to Noncontrolling Interest	13		5	21	18
Net Income (Loss) from Continuing Operations Available to Common Shareholders, Basic and Diluted	470		370	278	(81)
Income from discontinued operations after income taxes	(1,077)		323	(717)	674
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Noncontrolling Interest	1		(1)	5	6
Net Income (Loss) from Discontinued Operations Available to Common Shareholders, Basic	(1,078)		324	(722)	668
Net Income (Loss) Available to Common Stockholders, Basic and Diluted	$ (608)		$ 694	$ (444)	$ 587

Amount after tax of income (loss) from a discontinued operation including the portion attributable to the noncontrolling interest. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

Amount after tax of income (loss) from a discontinued operation attributable to the noncontrolling interest. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

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+ Details