Stockholders' Equity (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Jun. 29, 2013
Amounts Reclassified from AOCI
Interest expense	$ (780)	$ (831)	$ (1,578)	$ (1,673)
Interest income	200	152	502	487
Income before income taxes	20,216	18,464	29,796	38,542
Income tax (provision) benefit	(5,937)	(5,852)	(7,407)	(5,896)
Net income	14,279	12,612	22,389	32,646
Reclassifications From Accumulated Other Comprehensive Loss
Amounts Reclassified from AOCI
Income before income taxes	(143)	91	(286)	(90)
Income tax (provision) benefit	50	(32)	100	32
Net income	(93)	59	(186)	(58)
Losses on cash flow hedge | Reclassifications From Accumulated Other Comprehensive Loss
Amounts Reclassified from AOCI
Interest expense	(143)	(141)	(286)	(322)
Gains on available-for-sales securities | Reclassifications From Accumulated Other Comprehensive Loss
Amounts Reclassified from AOCI
Interest income		$ 232		$ 232