Supplemental Balance Sheet Information (Details 1) (USD $) In Thousands, unless otherwise specified	6 Months Ended
Jun. 30, 2012	Jul. 02, 2011
Accrued Warranty Obligations
Balance at beginning of year	$ 4,466	$ 4,105
Additions charged to cost of sales	1,290	1,862
Additions from acquisitions	21
Warranty claims	(1,749)	(1,936)
Balance at end of period	$ 4,028	$ 4,031

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Carrying value as of the balance sheet date of obligations incurred through that date and payable for estimated claims under standard and extended warranty protection rights granted to customers.

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Total liability for standard and extended product warranties acquired in a business acquisition.

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Represents the aggregate decrease in the liability related to payments to satisfy claims for standard and extended product warranties.

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The expense charged against earnings for the period pertaining to standard and extended warranties on the entity's goods and services granted to customers.

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