Consolidated Statements of Changes in Equity (USD $) In Millions, except Share data, unless otherwise specified	Common Stock	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock	Noncontrolling Interests	Total
Balance at beginning of period at Dec. 31, 2011	$ 0.3	$ 188.9	$ 2,102.7	$ (120.1)		$ 13.0	$ 2,184.8
Balance (in shares) at Dec. 31, 2011	326
Increase (Decrease) In Shareholders' Equity
Net income			555.3			4.2	559.5
Other comprehensive income				3.1		0.2	3.3
Distributions to shareholders of noncontrolling interests						(5.2)	(5.2)
Purchase of treasury stock					(380.1)		(380.1)
Retirement of treasury stock			(380.1)		380.1
Retirement of treasury stock (in shares)	(12)
Stock options exercised, including tax benefit		116.2					116.2
Stock options exercised, including tax benefit (in shares)	6
Dividends declared ($0.21, $0.305 and $0.45 per common share) for the year ended December 31, 2012, 2013 and 2014, respectively			(67.7)				(67.7)
Stock-based compensation		31.4					31.4
Balance at end of period at Dec. 31, 2012	0.3	336.5	2,210.2	(117.0)		12.2	2,442.2
Balance (in shares) at Dec. 31, 2012	320
Increase (Decrease) In Shareholders' Equity
Net income			635.7			3.0	638.7
Other comprehensive income				61.7		0.5	62.2
Purchase of noncontrolling interest		0.7		0.3		(1.0)
Acquisitions resulting in noncontrolling interests						10.3	10.3
Distributions to shareholders of noncontrolling interests						(4.4)	(4.4)
Purchase of treasury stock					(324.7)		(324.7)
Retirement of treasury stock			(324.7)		324.7
Retirement of treasury stock (in shares)	(8)
Stock options exercised, including tax benefit		116.5					116.5
Stock options exercised, including tax benefit (in shares)	4
Dividends declared ($0.21, $0.305 and $0.45 per common share) for the year ended December 31, 2012, 2013 and 2014, respectively			(96.8)				(96.8)
Stock-based compensation		36.1					36.1
Balance at end of period at Dec. 31, 2013	0.3	489.8	2,424.4	(55.0)		20.6	2,880.1
Balance (in shares) at Dec. 31, 2013	316						316,412,236
Increase (Decrease) In Shareholders' Equity
Net income			709.1			6.1	715.2
Other comprehensive income				(150.8)		(0.5)	(151.3)
Acquisitions resulting in noncontrolling interests						7.9	7.9
Distributions to shareholders of noncontrolling interests						(3.6)	(3.6)
Purchase of treasury stock					(539.4)		(539.4)
Retirement of treasury stock			(539.4)		539.4
Retirement of treasury stock (in shares)	(11)
Stock options exercised, including tax benefit		128.2					128.2
Stock options exercised, including tax benefit (in shares)	5
Dividends declared ($0.21, $0.305 and $0.45 per common share) for the year ended December 31, 2012, 2013 and 2014, respectively			(140.6)				(140.6)
Stock-based compensation		41.4					41.4
Balance at end of period at Dec. 31, 2014	$ 0.3	$ 659.4	$ 2,453.5	$ (205.8)		$ 30.5	$ 2,937.9
Balance (in shares) at Dec. 31, 2014	310						309,884,741