Condensed Consolidated Balance Sheets (UNAUDITED) (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Receivables, allowance for expected losses	$ 12.6	$ 10.5
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, authorized	1,000,000.0	1,000,000.0
Preferred stock, Issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, Authorized	65,000,000.0	65,000,000.0
Common stock, Issued	35,600,000	34,900,000
Common stock, Outstanding	33,600,000	33,300,000
Treasury stock, Shares	2,000,000.0	1,600,000