Note 3 - Stock-based Compensation - Stock-based Compensation Plan Expenses (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Share based compensation expense		$ 18,562	$ 16,010
Tax benefit related to stock-based compensation	[1]	470	838
Cost of Sales [Member]
Share based compensation expense		557	531
Research and Development Expense [Member]
Share based compensation expense		4,370	4,429
Selling, General and Administrative Expenses [Member]
Share based compensation expense		$ 13,635	$ 11,050

[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.