Note 3 - Stock-based Compensation - Stock-based Compensation Plan Expenses (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Share based compensation expense		$ 21,044	$ 22,709	$ 39,606	$ 38,719
Tax benefit related to stock-based compensation	[1]	468	706	938	1,544
Cost of Sales [Member]
Share based compensation expense		642	663	1,199	1,193
Research and Development Expense [Member]
Share based compensation expense		4,962	5,412	9,332	9,841
Selling, General and Administrative Expenses [Member]
Share based compensation expense		$ 15,440	$ 16,634	$ 29,075	$ 27,685

[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.