Property, Plant and Equipment (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013	Dec. 28, 2013
Components of property, plant and equipment
Total property, plant and equipment, gross	$ 80,227,000		$ 80,227,000		$ 72,784,000
Accumulated depreciation and amortization	(29,491,000)		(29,491,000)		(25,345,000)
Total property, plant and equipment, net	50,736,000		50,736,000		47,439,000
Depreciation expense	1,700,000	1,400,000	4,900,000	4,000,000
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	19,826,000		19,826,000		19,403,000
Machinery and equipment [Member]
Components of property, plant and equipment
Total property, plant and equipment, gross	31,569,000		31,569,000		27,820,000
Furniture and fixtures [Member]
Components of property, plant and equipment
Total property, plant and equipment, gross	2,343,000		2,343,000		2,308,000
Software [Member]
Components of property, plant and equipment
Total property, plant and equipment, gross	7,844,000		7,844,000		1,851,000
Capital in progress [Member]
Components of property, plant and equipment
Total property, plant and equipment, gross	$ 3,070,000		$ 3,070,000		$ 5,833,000