Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 29, 2012	Dec. 31, 2011	Dec. 25, 2010
Number of common stock shares excluded from computation of diluted income per share		1,956,000	1,724,000
Net of allowance for doubtful accounts	$ 300,000	$ 500,000
Product warrant period	12- to 36-months
Largest amount of tax benefit likely of being realize upon settlement	50.00%
Minority portion of purchase price payable upon customer acceptance	20.00%
Majority portion of revenue recognized upon shipment and transfer of title	80.00%
Deferred revenue	3,600,000	6,600,000
Deferred profit	2,139,000	2,821,000
Accumulated other comprehensive loss	1,783,000	(12,000)
Reserve for excess and obsolete inventories [Member]
Additions (Reductions) Charged (Credited) to Expense	$ 8,884,000	$ 5,796,000	1,743,000
Minimum [Member] | Buildings [Member]
Property, plant and equipment estimated useful lives	30 years
Minimum [Member] | Building improvements [Member]
Property, plant and equipment estimated useful lives	5 years
Minimum [Member] | Machinery, equipment and software [Member]
Property, plant and equipment estimated useful lives	3 years
Maximum [Member] | Buildings [Member]
Property, plant and equipment estimated useful lives	40 years
Maximum [Member] | Building improvements [Member]
Property, plant and equipment estimated useful lives	15 years
Maximum [Member] | Machinery, equipment and software [Member]
Property, plant and equipment estimated useful lives	10 years