Inventories (Details) (USD $)	Sep. 29, 2013	Dec. 30, 2012
Inventory Disclosure [Abstract]
Raw materials	$ 13,333,000	$ 18,325,000
Work in process	29,952,000	31,525,000
Finished goods	24,380,000	22,098,000
Inventories	67,665,000	71,948,000
Inventory, noncurrent	5,600,000	6,500,000
Supplies inventory	$ 8,700,000	$ 10,200,000