Note 9 - Stockholders' Equity and Stock-based Compensation (Tables)

9 Months Ended

Sep. 30, 2022

Notes Tables

Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2022		2021		2022		2021
	(in thousands)				(in thousands)
Cost of revenues	$	1,384	$	986	$	3,739	$	2,702
Research and development		3,236		2,723		10,064		7,520
Sales and marketing		2,495		1,642		6,829		4,356
General and administrative		6,176		4,112		17,224		41,640
Total stock-based compensation	$	13,291	$	9,463	$	37,856	$	56,218

Share-Based Payment Arrangement, Option, Activity [Table Text Block]

				Weighted		Weighted Average
	Outstanding			Average		Remaining		Aggregate
	Options			Exercise Price		Contractual Life		Intrinsic Value
	(in thousands)					(Years)		(in thousands)
Balance as of December 31, 2021		1,838		$	66.05		6.0	$	130,791
Granted		438		$	130.97
Exercised		(429	)	$	54.00
Canceled		(122	)	$	112.66
Balance as of September 30, 2022		1,725		$	82.24		6.5	$	67,404
Vested and expected to vest - September 30, 2022		1,512		$	76.56		6.1	$	66,670
Exercisable - September 30, 2022		948		$	50.98		4.3	$	63,624

Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]

					Weighted Average
					Grant Date
	Outstanding				Fair Value
	RSUs				Per Share
	(in thousands)
Balance as of December 31, 2021		917		(1)	$	104.78
Granted		278			$	133.00
Vested		(248	)		$	99.25
Canceled		(122	)		$	116.40
Balance as of September 30, 2022		825		(1)	$	114.13
Outstanding and expected to vest - September 30, 2022		700			$	112.22

Share Repurchase Program [Table Text Block]

Announcement Date	Authorized Dollar Value
	(in millions)
February 12, 2018	$	100.0
October 30, 2018		100.0
October 30, 2019		100.0
May 7, 2020		100.0
February 10, 2021		100.0
November 3, 2021		200.0
May 4, 2022		200.0
Total as of September 30, 2022	$	900.0