Cash, Cash Equivalents and Investments (Details 6) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 29, 2012	Dec. 31, 2011	Jan. 01, 2011
Carrying value of non-marketable investments
Cost method	$ 3,038	$ 6,157
Equity method	4,249	4,303
Total non-marketable investments	7,287	10,460
Net realized gains on the sale of non-marketable investments
Gains on sale of non-marketable investments	2,895	8,281	4,916
Write Downs Related to Cost method Investments [Abstract]
Write-down of cost method investments	1,103	0	1,500
Losses Related to Equity Method Investments [Abstract]
Gain (loss) From Non-marketable Equity Securities	$ 65	$ 136	$ 133