Note 1 - Summary of Significant Accounting Policies (Details Textual) - USD ($)		3 Months Ended		9 Months Ended
	Oct. 01, 2014	Sep. 26, 2015	Sep. 27, 2014	Sep. 26, 2015	Sep. 27, 2014	Oct. 01, 2015	Dec. 27, 2014
Semiconductor Equipment [Member]
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount						35.00%
Goodwill, Impairment Loss	$ 0
Allowance for Doubtful Accounts Receivable, Current		$ 100,000		$ 100,000			$ 200,000
Foreign Currency Transaction Gain (Loss), Realized		$ 1,500,000	$ 1,000,000	$ 1,100,000	$ 900,000
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		857,000	1,346,000	912,000	1,953,000
Deferred Revenue		$ 8,600,000		$ 8,600,000			10,700,000
Deferred Profit		5,732,000		5,732,000			6,941,000
Accumulated Other Comprehensive Income (Loss), Net of Tax		$ (20,501,000)		$ (20,501,000)			$ (10,714,000)