Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 6.8	$ 8.4
Inventory reserves	$ 17.4	$ 13.4
Preferred stock, par value per share (in dollars per share)	$ 0.10	$ 0.10
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Common stock, par value per share (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized	400,000,000	400,000,000
Common stock, shares issued	230,002,826	227,638,738
Common stock, shares outstanding	180,394,303	193,482,383
Common stock in treasury, shares	49,608,523	34,156,355