CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Millions	Total	Parent	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Noncontrolling Interest
Stockholders' Equity Balance at the Beginning of Period at Dec. 31, 2012	$ 2,249.4	$ 2,208.7	$ 1.6	$ 246.5	$ 2,818.5	$ (144.2)	$ (713.7)	$ 40.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	318.2	313.2			313.2			5.0
Other comprehensive income	77.3	75.1				75.1		2.2
Acquisition of noncontrolling interest	(8.9)	(3.9)		(3.9)				(5.0)
Exercise of stock options	66.9	66.9		(7.3)			74.2
Tax benefit from stock options exercised	2.4	2.4		2.4
Share based compensation expense	25.1	25.1		25.1
Funding of Employee Stock Ownership Plan	4.7	4.7		1.0			3.7
Treasury shares purchased	(118.0)	(118.0)					(118.0)
RSU distributions	(3.5)	(3.5)		(8.8)			5.3
RSU dividends				0.3	(0.3)
Cash dividends	(35.7)	(35.7)			(35.7)
Stockholders' Equity Balance at the End of Period at Dec. 31, 2013	$ 2,577.9	2,535.0	1.6	255.3	3,095.7	(69.1)	(748.5)	42.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, cash dividends per share	$ 0.250
Net Income	$ 322.9	322.9			322.9			0.0
Other comprehensive income	(367.2)	(366.5)				(366.5)		(0.7)
Acquisition of noncontrolling interest	(88.8)	(47.5)		(42.0)		(5.5)		(41.3)
Exercise of stock options	49.0	49.0		(9.7)			58.7
Tax benefit from stock options exercised	2.1	2.1		2.1
Share based compensation expense	25.4	25.4		25.4
Funding of Employee Stock Ownership Plan	5.9	5.9		1.5			4.4
Treasury shares purchased	(163.2)	(163.2)					(163.2)
RSU distributions	(4.2)	(4.2)		(11.2)			7.0
RSU dividends				0.3	(0.3)
Cash dividends	(37.6)	(37.6)			(37.6)
Stockholders' Equity Balance at the End of Period at Dec. 31, 2014	$ 2,322.2	2,321.3	1.6	221.7	3,380.7	(441.1)	(841.6)	0.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, cash dividends per share	$ 0.265
Net Income	$ 251.1	251.2			251.2			(0.1)
Other comprehensive income	(152.3)	(152.9)				(152.9)		0.6
Exercise of stock options	35.2	35.2		(8.2)			43.4
Tax benefit from stock options exercised	11.6	11.6		11.6			0.0
Share based compensation expense	25.6	25.6		25.6
Funding of Employee Stock Ownership Plan	4.7	4.7		1.1			3.6
Treasury shares purchased	(112.7)	(112.7)					(112.7)
RSU distributions	(5.4)	(5.4)		(14.3)			8.9
RSU dividends				0.3	(0.3)
Cash dividends	(40.6)	(40.6)			(40.6)
Stockholders' Equity Balance at the End of Period at Dec. 31, 2015	$ 2,339.4	$ 2,338.0	$ 1.6	$ 237.8	$ 3,591.0	$ (594.0)	$ (898.4)	$ 1.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, cash dividends per share	$ 0.29