Condensed Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for trade receivables	$ 44.0	$ 38.7
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in USD per share)	$ 0.10	$ 0.10
Common stock, shares authorized (in shares)	260,000,000	260,000,000
Common stock, shares issued (in shares)	185,983,792	185,983,792
Treasury stock, shares (in shares)	51,469,535	51,653,236