Equity, Stock-Based Compensation (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Expense incurred for stock-based compensation plans									$ 55.6	$ 49.7	$ 47.6
Recognized tax benefit related to stock-based compensation									27.5	78.3	11.4
Excess tax benefit from option exercises	$ 5.7	$ 7.0	$ 3.0	$ 4.1	$ 20.8	$ 16.6	$ 21.2	$ 8.0	19.8	66.6	0.0
Selling, General and Administrative Expenses
Expense incurred for stock-based compensation plans									$ 55.6	$ 49.7	$ 47.6

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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Amount of tax benefit from exercise of stock options granted under share-based compensation arrangement.

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