Other Income (Expense), Net (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013
Other Income (Expense), Net
Interest income	$ 507	$ 366	$ 1,490	$ 1,275
Gains on marketable debt and equity securities, net	615	1,363	682	1,339
Gains (losses) on non-marketable investments, net	(479)	(11)	1,473	1,102
Gains (losses) on securities in NQDC trust	(104)	206	3,005	2,057
Gains (losses) on foreign exchange	935	489	(235)	1,476
Write-down of non-marketable investments	(1,956)	0	(1,956)	(464)
Other income (expense), net	65	122	141	(57)
Total other income (expense), net	$ (417)	$ 2,535	$ 4,600	$ 6,728