Unaudited Condensed Consolidated Statements Of Shareholders' Equity - USD ($) $ in Millions	Total	Common shares	Treasury Shares	Accumulated Other Comprehensive Income	Retained Earnings
Balance, at beginning of period at Dec. 31, 2014	$ 3,778.2	$ 408.0	$ (143.1)	$ 0.0	$ 3,513.3
Net income	133.8				133.8
Dividends	(45.1)				(45.1)
Stock compensation	6.4		15.5		(9.1)
Share repurchases	(245.3)		(245.3)
Shares cancelled	0.0	(21.3)	213.7		(192.4)
Foreign currency translation adjustment	(3.3)			(3.3)
Balance, at end of period at Jun. 30, 2015	3,624.7	386.7	(159.2)	(3.3)	3,400.5
Balance, at beginning of period at Dec. 31, 2015	3,532.5	386.7	(155.1)	(9.3)	3,310.2
Net income	227.5				227.5
Dividends	(46.2)				(46.2)
Stock compensation	7.4		11.7		(4.3)
Share repurchases	(140.0)		(140.0)
Shares cancelled	0.0	(20.0)	66.7		(46.7)
Foreign currency translation adjustment	3.3			3.3
Balance, at end of period at Jun. 30, 2016	$ 3,584.5	$ 366.7	$ (216.7)	$ (6.0)	$ 3,440.5