Earnings Per Share (Calculation of EPS) (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Income/(loss) from continuing operations, net of taxes	$ 551.2	$ (368.5)	$ 1,147.5	$ 127.6
(Loss)/gain from discontinued operations, net of taxes	(0.4)	(18.3)	18.6	(257.5)
Net income/(loss)	$ 550.8	$ (386.8)	$ 1,166.1	$ (129.9)
Weighted average number of shares:
Basic (in shares)	907.2	900.2	905.9	725.5
Effect of dilutive shares:
Share-based awards to employees (in shares)	4.4	0.0	6.2	0.0
Diluted (in shares)	911.6	900.2	912.1	725.5

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Amount after tax of income (loss) from continuing operations including portion attributable to the noncontrolling interest.

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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.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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