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

6 Months Ended

Jun. 30, 2022

Notes Tables

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

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2022		2021		2022		2021
	(in thousands)				(in thousands)
Cost of revenues	$	1,273	$	841	$	2,355	$	1,716
Research and development		3,541		2,582		6,828		4,797
Sales and marketing		2,305		1,086		4,334		2,714
General and administrative		5,701		4,044		11,048		37,528
Total stock-based compensation	$	12,820	$	8,553	$	24,565	$	46,755

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		278		$	135.01
Exercised		(212	)	$	42.72
Canceled		(89	)	$	111.97
Balance as of June 30, 2022		1,815		$	77.08		6.2	$	91,404
Vested and expected to vest - June 30, 2022		1,618		$	71.75		5.9	$	89,608
Exercisable - June 30, 2022		1,087		$	49.76		4.4	$	83,037

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		190			$	137.19
Vested		(160	)		$	98.01
Canceled		(83	)		$	116.12
Balance as of June 30, 2022		864		(1)	$	111.89
Outstanding and expected to vest - June 30, 2022		749			$	110.04

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 June 30, 2022	$	900.0