CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Receivables, allowance for credit losses	$ 15.9	$ 14.3
Preferred stock, par value	$ 1.00	$ 1.00
Preferred stock, authorized	2,000,000.0	2,000,000.0
Preferred stock, Issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, Authorized	165,000,000.0	165,000,000.0
Common stock, Issued	89,000,000.0	89,000,000.0
Treasury stock, shares	17,600,000	18,100,000