SUPPLEMENTAL BALANCE SHEET INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	Mar. 29, 2014	Dec. 28, 2013
Short-term inventories
Raw materials and purchased parts	$ 61,733	$ 61,819
Work in process	19,914	19,577
Finished goods	23,637	21,987
Short-term inventories	105,284	103,383
Long-term Inventories
Raw materials and purchased parts	2,906	1,850
Finished goods	3,101	4,489
Long-term inventories	$ 6,007	$ 6,339