Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Accounts Receivable, Allowance for Credit Loss	$ 4.8	$ 4.8
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	39,797,000	39,614,000
Treasury stock, shares	144,000	135,000