Income Taxes (Net Deferred Tax Assets and Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 30, 2012	Jan. 01, 2012
Deferred tax assets:
Net operating losses and capital losses	$ 38,342	$ 34,733
Accruals and reserves	2,683	2,753
Credits carryforward	5,024	5,304
Unrealized loss on marketable securities	3,088	3,057
Depreciation and amortization	9,558	9,150
Stock-based compensation	1,344	971
Other	273	211
Deferred tax assets, gross	60,312	56,179
Valuation allowance	(60,223)	(56,067)
Deferred tax asset	89	112
Deferred tax liability	$ 0	$ 0