Cash, Cash Equivalents and Short-Term Investments (Details) (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 29, 2012	Dec. 31, 2011
Investment [Line Items]
Variable rate demand note maturity year	2037
Variable Rate Demand Notes [Member]
Investment [Line Items]
Securities amortized cost Due in one year or less	$ 1,500	$ 1,500
Securities fair value Due in one year or less	$ 1,900	$ 1,900