Note 7 - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 26, 2015	Dec. 27, 2014
Inventory, receivable and warranty reserves	$ 8,207	$ 9,585
Net operating loss carryforwards	7,605	8,266
Tax credit carryforwards	12,291	11,905
Accrued employee benefits	4,993	5,232
Deferred profit and gain on facility sale	6,084	1,091
Stock-based compensation	4,443	4,352
Acquisition basis differences	1,544	2,133
Other	265	608
Gross deferred tax assets	45,432	43,172
Less valuation allowance	(42,289)	(37,023)
Total deferred tax assets	3,143	6,149
Depreciation and fixed asset related	227	1,822
Acquisition basis differences	8,904	10,600
Other	563	643
Total deferred tax liabilities	9,694	13,065
Net deferred income tax assets (liabilities)	$ (6,551)	$ (6,916)