Earnings Per Share (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended	12 Months Ended
Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014
Schedule of Calculation of Numerator and Denominator in Earnings Per Share
Income from continuing operations, net of taxes (in USD)	$ 409.5	$ 412.9
Gain/(loss) from discontinued operations, net of taxes (in USD)	9.5	(2.5)
Numerator for basic earnings per share	$ 419.0	$ 410.4	$ 419.0	$ 410.4
Schedule of Weighted Average Number of Shares
Basic (in shares)	591.7	589.1
Effect of dilutive shares:
Share based awards to employees (in shares)	1.6	3.6
Diluted (in shares)	593.3	592.7
Share Awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	4.0	1.4

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses and taxes from ongoing operations before extraordinary items, and 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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