Convertible Senior Notes (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 29, 2013	Sep. 30, 2012	Sep. 29, 2013	Sep. 30, 2012
Interest Expense, Debt [Abstract]
Contractual coupon interest expense	$ 624	$ 638	$ 1,871	$ 1,835
Accretion of discount on the liability component	$ 9,063	$ 8,801	$ 27,095	$ 26,100

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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