Changes in Equity and Noncontrolling Interests (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Increase (Decrease) In Shareholders' Equity
Balance at beginning of period	$ 3,723.1	$ 3,278.4
Net income	227.3	158.4
Other comprehensive income (loss)	67.2	52.4
Distributions to shareholders of noncontrolling interests	(4.2)	(4.0)
Purchase of treasury stock	(249.2)	(49.2)
Stock options exercised	23.7	19.6
Dividends declared	(48.9)	(43.0)
Stock-based compensation expense	12.1	11.6
Balance at end of period	$ 3,751.1	$ 3,424.2
Common Stock
Increase (Decrease) In Shareholders' Equity
Balance (in shares)	308.3	308.0
Balance at beginning of period	$ 0.3	$ 0.3
Retirement of treasury stock (in shares)	(3.7)	(1.0)
Stock options exercised (in shares)	0.8	0.7
Balance (in shares)	305.4	307.7
Balance at end of period	$ 0.3	$ 0.3
Additional Paid-In Capital
Increase (Decrease) In Shareholders' Equity
Balance at beginning of period	1,020.9	783.3
Stock options exercised	23.7	19.6
Stock-based compensation expense	12.1	11.6
Balance at end of period	1,056.7	814.5
Retained Earnings
Increase (Decrease) In Shareholders' Equity
Balance at beginning of period	3,122.7	2,804.4
Net income	224.9	156.6
Retirement of treasury stock	(249.2)	(49.2)
Dividends declared	(48.9)	(43.0)
Balance at end of period	3,049.5	2,868.8
Accumulated Other Comprehensive Loss
Increase (Decrease) In Shareholders' Equity
Balance at beginning of period	(469.0)	(349.5)
Other comprehensive income (loss)	66.7	52.1
Balance at end of period	(402.3)	(297.4)
Treasury Stock
Increase (Decrease) In Shareholders' Equity
Purchase of treasury stock	(249.2)	(49.2)
Retirement of treasury stock	249.2	49.2
Noncontrolling Interests
Increase (Decrease) In Shareholders' Equity
Balance at beginning of period	48.2	39.9
Net income	2.4	1.8
Other comprehensive income (loss)	0.5	0.3
Distributions to shareholders of noncontrolling interests	(4.2)	(4.0)
Balance at end of period	$ 46.9	$ 38.0