Note 3 - Stock-based Compensation - Stock-based Compensation Plan Expenses (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share based compensation expense		$ 22,975	$ 21,300	$ 62,581	$ 60,019
Tax benefit related to stock-based compensation	[1]	512	595	1,450	2,139
Cost of Sales [Member]
Share based compensation expense		707	641	1,906	1,834
Research and Development Expense [Member]
Share based compensation expense		5,334	4,960	14,666	14,801
Selling, General and Administrative Expenses [Member]
Share based compensation expense		$ 16,934	$ 15,699	$ 46,009	$ 43,384

[1] Amounts reflect the tax benefit related to stock-based compensation recorded for equity awards that are expected to generate tax deductions when they vest in future periods.