Note 1 - Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 25, 2016

Notes Tables

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]

	Three Months Ended						Six Months Ended
	June 25, 2016			June 27, 2015			June 25, 2016			June 27, 2015
Cost of sales	$	170		$	198		$	104		$	313
Research and development		294			254			710			585
Selling, general and administrative		1,187			1,294			2,794			2,546
Total share-based compensation		1,651			1,746			3,608			3,444
Income tax benefit		(73	)		(67	)		(113	)		(111	)
Total share-based compensation, net	$	1,578		$	1,679		$	3,495		$	3,333

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	Three Months Ended				Six Months Ended
	June 25, 2016		June 27, 2015		June 25, 2016		June 27, 2015
Weighted average common shares		26,711		26,059		26,514		25,905
Effect of dilutive share-based compensation awards		647		663		836		715
		27,358		26,722		27,350		26,620

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

	Three Months Ended						Six Months Ended
	June 25,			June 27,			June 25,			June 27,
	2016			2015			2016			2015
Customers individually accounting for more than 10% of net sales		one			three			two			three
Percentage of net sales		21.7	%		40.9	%		32.0	%		38.5	%