Note 4 - Balance Sheet Components (Tables)

3 Months Ended

Mar. 31, 2021

Notes Tables

Schedule of Inventory, Current [Table Text Block]

	March 31,		December 31,
	2021		2020
Raw materials	$	26,055	$	25,503
Work in process		90,571		77,100
Finished goods		58,597		54,459
Total	$	175,223	$	157,062

Schedule of Other Current Assets [Table Text Block]

	March 31,		December 31,
	2021		2020
RSU tax withholding proceeds receivable	$	11,428	$	12,504
Prepaid expense		7,225		5,032
Accrued interest receivable		2,126		1,914
Assets for product returns		1,724		1,684
Other		1,822		1,846
Total	$	24,325	$	22,980

Schedule of Other Assets, Noncurrent [Table Text Block]

	March 31,		December 31,
	2021		2020
Deferred compensation plan assets	$	48,138	$	46,146
Operating lease right-of-use (“ROU”) assets		5,845		3,719
Prepaid expense		2,503		2,340
Debt investment		2,820		2,861
Equity investment in a privately held company		3,180		3,400
Other		1,296		1,372
Total	$	63,782	$	59,838

Schedule of Accrued Liabilities [Table Text Block]

	March 31,		December 31,
	2021		2020
Dividends and dividend equivalents	$	31,472	$	26,435
Stock rotation and sales returns		6,240		6,005
Accrued purchases of property and equipment		5,339		5,841
Income tax payable		5,545		3,755
Customer prepayments		6,998		7,238
Commissions		1,252		1,107
Operating lease liabilities		1,953		1,406
Warranty		9,941		6,895
Other		5,627		4,278
Total	$	74,367	$	62,960

Other Noncurrent Liabilities [Table Text Block]

	March 31,		December 31,
	2021		2020
Deferred compensation plan liabilities	$	49,837	$	48,280
Dividend equivalents		8,323		7,871
Operating lease liabilities		3,454		1,693
Other		30		29
Total	$	61,644	$	57,873