CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jul. 02, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Accounts receivable, allowance	$ 246	$ 274
Preferred shares, no par value	$ 0	$ 0
Preferred shares, Authorized	7,000,000	7,000,000
Preferred shares, Issued	0	0
Preferred shares, outstanding	0	0
Common shares, Authorized	Unlimited	Unlimited
Common shares, no par value	$ 0	$ 0
Common shares, Issued	35,489,000	35,163,000
Common shares, outstanding	35,489,000	35,163,000