Property, Plant and Equipment (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Jun. 29, 2013	Dec. 28, 2013
Components of property, plant and equipment
Total property, plant and equipment, gross	$ 75,229,000		$ 75,229,000		$ 72,784,000
Accumulated depreciation and amortization	(27,985,000)		(27,985,000)		(25,345,000)
Total property, plant and equipment, net	47,244,000		47,244,000		47,439,000
Depreciation expense	1,600,000	1,300,000	3,200,000	2,600,000
Land [Member]
Components of property, plant and equipment
Total property, plant and equipment, gross	15,575,000		15,575,000		15,569,000
Building and improvements [Member]
Components of property, plant and equipment
Total property, plant and equipment, gross	19,803,000		19,803,000		19,403,000
Machinery and equipment [Member]
Components of property, plant and equipment
Total property, plant and equipment, gross	28,146,000		28,146,000		27,820,000
Furniture and fixtures [Member]
Components of property, plant and equipment
Total property, plant and equipment, gross	2,362,000		2,362,000		2,308,000
Software [Member]
Components of property, plant and equipment
Total property, plant and equipment, gross	7,810,000		7,810,000		1,851,000
Capital in progress [Member]
Components of property, plant and equipment
Total property, plant and equipment, gross	$ 1,533,000		$ 1,533,000		$ 5,833,000