Property, Plant and Equipment (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 29, 2013	Jun. 30, 2012	Jun. 29, 2013	Jun. 30, 2012	Dec. 29, 2012
Components of property, plant and equipment
Total property, plant and equipment, gross	$ 66,142,000		$ 66,142,000		$ 62,932,000
Accumulated depreciation	(22,311,000)		(22,311,000)		(19,719,000)
Total property, plant and equipment, net	43,831,000		43,831,000		43,213,000
Property, Plant and Equipment (Details Textual)
Depreciation expense	1,300,000	1,200,000	2,600,000	2,200,000
Land [Member]
Components of property, plant and equipment
Total property, plant and equipment, gross	15,570,000		15,570,000		15,573,000
Building and improvements [Member]
Components of property, plant and equipment
Total property, plant and equipment, gross	19,377,000		19,377,000		19,231,000
Machinery and equipment [Member]
Components of property, plant and equipment
Total property, plant and equipment, gross	25,136,000		25,136,000		21,523,000
Furniture and fixtures [Member]
Components of property, plant and equipment
Total property, plant and equipment, gross	2,299,000		2,299,000		2,228,000
Capital in progress [Member]
Components of property, plant and equipment
Total property, plant and equipment, gross	$ 3,760,000		$ 3,760,000		$ 4,377,000