Note 4 - Balance Sheet Components (Tables)

3 Months Ended

Mar. 31, 2020

Notes Tables

Schedule of Inventory, Current [Table Text Block]

	March 31,		December 31,
	2020		2019
Raw materials	$	32,502	$	22,872
Work in process		48,022		42,681
Finished goods		50,975		61,947
Total	$	131,499	$	127,500

Schedule of Other Current Assets [Table Text Block]

	March 31,		December 31,
	2020		2019
RSU tax withholding proceeds receivable	$	5,744	$	6,106
Prepaid expense		18,444		7,991
Accrued interest receivable		2,530		2,490
Assets for product returns		1,824		1,585
Other		1,137		1,433
Total	$	29,679	$	19,605

Schedule of Other Assets, Noncurrent [Table Text Block]

	March 31,		December 31,
	2020		2019
Deferred compensation plan assets	$	35,547	$	38,858
Operating lease right-of-use (“ROU”) assets		2,744		2,863
Prepaid expense		2,715		2,687
Other		1,457		1,544
Total	$	42,463	$	45,952

Schedule of Accrued Liabilities [Table Text Block]

	March 31,		December 31,
	2020		2019
Dividends and dividend equivalents	$	27,846	$	21,747
Stock rotation and sales returns		6,474		5,530
Accrued purchases of property and equipment		5,834		4,678
Income tax payable		2,462		2,435
Customer prepayments		5,221		3,412
Commissions		2,191		1,425
Operating lease liabilities		1,140		1,254
Warranty		1,144		1,139
Other		3,798		3,170
Total	$	56,110	$	44,790

Other Noncurrent Liabilities [Table Text Block]

	March 31,		December 31,
	2020		2019
Deferred compensation plan liabilities	$	36,627	$	39,665
Dividend equivalents		6,481		6,265
Operating lease liabilities		1,086		1,103
Other		29		30
Total	$	44,223	$	47,063