Unaudited Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 28, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Accounts receivable, net of allowance for doubtful accounts of $1,079 as of June 28, 2020 and December 31, 2019	$ 1,079	$ 1,079