CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Oct. 02, 2015	Dec. 31, 2014
Statement Of Financial Position [Abstract]
Accounts receivable, allowance	$ 311	$ 282
Common shares, no par value	$ 0	$ 0
Common shares, Issued	34,341	34,219
Common shares, outstanding	34,341	34,219