Note 4 - Balance Sheet Components (Tables)

6 Months Ended

Jun. 30, 2018

Notes Tables

Schedule of Inventory, Current [Table Text Block]

	June 30,		December 31,
	2018		2017
Raw materials	$	34,281	$	20,573
Work in process		50,446		40,030
Finished goods		44,182		38,678
Total	$	128,909	$	99,281

Schedule of Other Current Assets [Table Text Block]

	June 30,		December 31,
	2018		2017
Prepaid wafer purchase	$	6,217	$	6,217
Other prepaid expense		3,172		2,742
Interest receivable		1,466		1,352
Value-added tax receivable		1,427		1,235
Assets for product returns		1,047		-
Other		645		1,216
Total	$	13,974	$	12,762

Schedule of Other Assets, Noncurrent [Table Text Block]

	June 30,		December 31,
	2018		2017
Deferred compensation plan assets	$	29,224	$	28,080
Prepaid expense		816		897
Other		1,295		1,091
Total	$	31,335	$	30,068

Schedule of Accrued Liabilities [Table Text Block]

	June 30,		December 31,
	2018		2017
Dividends and dividend equivalents	$	14,266	$	9,248
Warranty		3,951		2,416
Stock rotation and sales returns		3,580		2,647
Customer prepayments		3,237		4,742
Income tax payable		3,376		2,861
Commissions		1,112		938
Sales rebate		819		1,036
Deferred income		-		1,845
Other		2,692		1,774
Total	$	33,033	$	27,507

Schedule of Product Warranty Liability [Table Text Block]

	Three Months Ended June 30,						Six Months Ended June 30,
	2018			2017			2018			2017
Balance at beginning of period	$	3,740		$	1,346		$	2,416		$	1,030
Warranty provision for product sales		335			1,512			1,814			2,303
Settlements made		(9	)		-			(64	)		(296	)
Unused warranty provision		(115	)		(231	)		(215	)		(410	)
Balance at end of period	$	3,951		$	2,627		$	3,951		$	2,627

Other Noncurrent Liabilities [Table Text Block]

	June 30,		December 31,
	2018		2017
Deferred compensation plan liabilities	$	29,197	$	28,087
Dividend equivalents		5,595		4,881
Other		79		56
Total	$	34,871	$	33,024