Capital Assets (Details) (USD $)	3 Months Ended		12 Months Ended
	Dec. 31, 2011	Jan. 01, 2011	Oct. 01, 2011
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 164,072,000		$ 162,620,000
Less accumulated depreciation	(107,911,000)		(106,368,000)
Property and equipment, net	56,161,000		56,252,000
Goodwill	16,197,000		16,027,000
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	33,126,000		35,012,000
Accumulated Amortization	(7,327,000)		(9,169,000)
Net Carrying Value	25,799,000		25,843,000
Weighted average useful life (in years)	14.3		13.6
Amortization expense	700,000	800,000
Software development costs [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	15,847,000		15,370,000
Accumulated Amortization	(4,054,000)		(3,574,000)
Net Carrying Value	11,793,000		11,796,000
Weighted average useful life (in years)	5.7		5.8
Amortization expense	500,000	400,000
Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	10,040,000		9,903,000
Accumulated Amortization	(2,323,000)		(2,114,000)
Net Carrying Value	7,717,000		7,789,000
Weighted average useful life (in years)	15.3		15.3
Trademarks and trade names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	6,002,000		5,924,000
Accumulated Amortization	(873,000)		(815,000)
Net Carrying Value	5,129,000		5,109,000
Weighted average useful life (in years)	30.2		30.2
Non-compete agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	0		2,596,000
Accumulated Amortization	0		(2,596,000)
Net Carrying Value	0		0
Weighted average useful life (in years)	0		3.0
Land-use rights [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,237,000		1,219,000
Accumulated Amortization	(77,000)		(70,000)
Net Carrying Value	1,160,000		1,149,000
Weighted average useful life (in years)	47.8		47.8
Land and improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,711,000		1,713,000
Building and improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	52,547,000		52,764,000
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 109,814,000		$ 108,143,000