Inventories (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 29, 2012	Dec. 31, 2011
Schedule of Inventory [Line Items]
Raw materials	$ 29,646	$ 28,675
Finished goods	8,750	7,251
Sales demonstration inventory	18,109	16,794
Reserve for excess and obsolete	(3,157)	(2,786)
Inventory	53,348	49,934
Service inventory	$ 19,535	$ 17,316

The amount of the valuation account as of the balance sheet date which reduces the carrying amount of inventory to net realizable value; takes into consideration such factors as market value, excessive quantities based on expected sales, technological obsolescence, and shrinkage. May also provide for estimated product returns or price concessions pertaining to product cost.

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

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+ Details