Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 01, 2016	Jul. 03, 2015	Jul. 01, 2016	Jul. 03, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net Income (loss)	$ 1,259	$ 554	$ (19,598)	$ 1,821
Foreign currency adjustment	(511)	422	170	(1,548)
Change in pension loss, net of taxes of $16 and $24 in the 2016 and 2015 second quarters, respectively, and $31 and $46 in the first two quarters of 2016 and 2015, respectively	179	(108)	(16)	807
Other comprehensive income (loss)	(332)	314	154	(741)
Comprehensive income (loss)	$ 927	$ 868	$ (19,444)	$ 1,080