Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Allowance for doubtful accounts	$ 1.9	$ 1.8
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	54,872,983	54,596,183
Common stock, shares outstanding	54,872,983	54,596,183