Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Trade receivables, net of allowance for doubtful accounts	$ 8.5	$ 8.4
Inventory reserves	$ 14.9	$ 13.4
Preferred stock, par value 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	$ 0.10	$ 0.10
Common stock, shares authorized	400,000,000	400,000,000
Common stock, shares issued	229,942,206	227,638,738
Common stock, shares outstanding	195,824,449	193,482,383
Common stock in treasury, shares	34,117,757	34,156,355