Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Receivables, allowances	$ 19.2	$ 9.4
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	12,000,000.0	12,000,000.0
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	600,000,000.0	600,000,000.0
Common stock, shares issued (in shares)	286,300,000	286,300,000
Common stock, shares outstanding (in shares)	226,800,000	231,500,000
Common stock held in employee benefit trust at cost (in shares)	200,000	200,000
Treasury stock, at cost (in shares)	59,400,000	54,600,000