Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Millions, $ in Millions	Dec. 31, 2021	Dec. 25, 2020
Statement Of Financial Position [Abstract]
Account receivable, allowance for doubtful accounts	$ 0.3	$ 0.3
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10.0	10.0
Preferred stock, shares outstanding	0.0	0.0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	90.0	90.0
Common stock, shares issued	44.9	40.6
Common stock, shares outstanding	44.9	40.6
Treasury stock, shares	0.6	0.6