SUPPLEMENTAL BALANCE SHEET INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	Jun. 28, 2014	Dec. 28, 2013
Short-term inventories
Raw materials and purchased parts	$ 65,979	$ 61,819
Work in process	18,800	19,577
Finished goods	26,867	21,987
Short-term inventories	111,646	103,383
Long-term Inventories
Raw materials and purchased parts	1,719	1,850
Finished goods	2,633	4,489
Long-term inventories	$ 4,352	$ 6,339