Note 4 - Balance Sheet Components (Tables)

3 Months Ended

Mar. 31, 2015

Disclosure Text Block Supplement [Abstract]

Schedule of Inventory, Current [Table Text Block]

	March 31,		December 31,
	2015		2014
Raw materials	$	8,853	$	7,298
Work in process		23,729		18,950
Finished goods		20,814		14,670
Total	$	53,396	$	40,918

Schedule of Other Assets, Noncurrent [Table Text Block]

	March 31,		December 31,
	2015		2014
Deferred compensation plan assets	$	8,386	$	6,084
Prepaid expense		1,348		1,418
Other		955		955
Total	$	10,689	$	8,457

Schedule of Accrued Liabilities [Table Text Block]

	March 31,		December 31,
	2015		2014
Dividends and dividend equivalents	$	8,196	$	6,080
Deferred revenue and customer prepayments		5,073		3,908
Stock rotation reserve		2,376		1,757
Commissions		833		767
Deferred compensation plan liabilities		704		-
Sales rebate		337		586
Warranty		296		240
Other		811		1,365
Total	$	18,626	$	14,703

Schedule of Product Warranty Liability [Table Text Block]

	Three Months Ended March 31,
	2015			2014
Balance at beginning of period	$	240		$	451
Warranty provision for product sales		74			60
Settlements made		-			(74	)
Unused warranty provision		(18	)		(103	)
Balance at end of period	$	296		$	334

Schedule of Other Assets and Other Liabilities [Table Text Block]

	March 31,		December 31,
	2015		2014
Deferred compensation plan liabilities	$	7,723	$	6,177
Contingent consideration		2,507		2,507
Dividend equivalents		1,064		580
Other		976		940
Total	$	12,270	$	10,204