Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 27, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Accounts receivable, allowances	$ 178	$ 84
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	27,017,824	27,017,824
Treasury stock, shares	11,949,599	12,311,010