CONSOLIDATED CONDENSED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 8.3	$ 8.5
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	50,000,000	50,000,000
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 1.00	$ 1.00
Common stock, shares authorized (in shares)	350,000,000	350,000,000
Common stock, shares issued (in shares)	214,800,000	212,000,000
Common stock, shares outstanding (in shares)	209,100,000	209,700,000
Treasury stock (in shares)	5,700,000	2,300,000