Note 5 - Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Inventory, receivable and warranty reserves	$ 3,417	$ 5,868
Net operating loss carryforwards	7,467	11,681
Tax credit carryforwards	14,724	13,715
Accrued employee benefits	4,796	5,002
Deferred profit and gain on facility sale	3,617	5,412
Stock-based compensation	1,897	4,189
Acquisition basis differences	1,606	1,334
Other	208	103
Gross deferred tax assets	37,732	47,304
Less valuation allowance	(31,491)	(44,731)
Total deferred tax assets	6,241	2,573
Depreciation and fixed asset related	120	53
Acquisition basis differences	5,518	7,423
Unremitted earnings of foreign subsidiaries	2,002
Other	437	662
Total deferred tax liabilities	8,077	8,138
Net deferred tax liabilities	$ (1,836)	$ (5,565)