Stockholders' Equity (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Amounts Reclassified from AOCI
Interest expense	$ (813)	$ (234)	$ (2,486)	$ (299)
Interest income	129	243	616	1,103
Income before income taxes	9,783	27,078	48,325	61,984
Income tax benefit	(3,252)	(17,054)	(9,148)	(17,131)
Net income	6,531	10,024	39,177	44,853
Reclassifications From Accumulated Other Comprehensive Loss
Amounts Reclassified from AOCI
Income before income taxes	(96)	(1,317)	(186)	(2,197)
Income tax benefit	33	461	65	769
Net income	(63)	(856)	(121)	(1,428)
Losses on cash flow hedge | Reclassifications From Accumulated Other Comprehensive Loss
Amounts Reclassified from AOCI
Rent expense		(1,317)		(2,197)
Interest expense	(96)		(418)
Gains on available-for-sales securities | Reclassifications From Accumulated Other Comprehensive Loss
Amounts Reclassified from AOCI
Interest income			$ 232