Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 2019

Stockholders' Equity Note [Abstract]

Share-based Compensation, Stock Options, Activity

A summary of employees’ stock options activities during the three months ended March 31, 2019 is as follows:

	Three Months Ended March 31, 2019 (unaudited)
	Number		Weighted average exercise price		Aggregate intrinsic value (in thousands)		Weighted average remaining contractual life (years)
Options outstanding as of January 1, 2019	709,668		$	17.941	$	24,810	4.513
Granted	—		$	—
Exercised	(149,132	)	$	5.503
Forfeited	—		$	—
Options outstanding as of March 31, 2019	560,536		$	21.250	$	21,514	5.069
Options exercisable as of March 31, 2019	548,421		$	21.343	$	20,997	5.029

Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range

The options outstanding as of March 31, 2019 (unaudited) have been separated into ranges of exercise price as follows:

Range of exercise price				Options outstanding as of March 31, 2019	Weighted average remaining contractual life (years)	Weighted average exercise price		Options exercisable as of March 31, 2019	Weighted average remaining contractual life (years)	Weighted average exercise price of options exercisable
$	1.256	—	1.576	8,970	0.892	$	1.562	8,970	0.892	$	1.562
$	6.230	—	8.800	12,356	2.760	$	8.039	12,356	2.760	$	8.039
$	12.470	—	16.870	144,925	4.778	$	14.052	133,465	4.596	$	13.749
$	19.510	—	21.660	201,472	5.371	$	21.160	200,817	5.369	$	21.164
$	22.010	—	24.230	85,361	5.037	$	22.366	85,361	5.037	$	22.366
		$29.880		64,725	5.899	$	29.880	64,725	5.899	$	29.880
		$39.860		42,727	4.978	$	39.860	42,727	4.978	$	39.860
				560,536	5.069	$	21.250	548,421	5.029	$	21.343

Schedule of Stockholders' Equity Note, Warrants or Rights

The Company’s outstanding options granted to consultants for services as of March 31, 2019 (unaudited) were as follows:

	Options for shares of common stock	Exercise price per share		Options exercisable	Exercisable through
	(number)			(number)
February 2013	1,500	$	12.470	1,500	February 2023
August 2013	4,000	$	21.140	4,000	August 2023
March 2014	5,550	$	39.860	5,550	March 2024
May 2014	3,700	$	22.010	3,700	May 2024
November 2014	5,468	$	21.660	5,468	November 2024
May 2015	1,137	$	19.510	1,055	May 2025
February 2016	2,138	$	16.870	1,563	February 2026
	23,493			22,836

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity

A summary of restricted stock units and performance stock units for employees, consultants and non-employee directors of the Company for the three months ended March 31, 2019 (unaudited) is as follows:

	Number of shares underlying outstanding restricted stock units		Weighted- average grant date fair value
Unvested balance - January 1, 2019	2,440,027		$	40.00
Granted	1,149,434		$	55.52
Vested	(622,523	)	$	35.95
Forfeited	(101,638	)	$	41.33
Unvested balance – March 31, 2019	2,865,300		$	47.09

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs

The Company recognized non-cash stock-based compensation expense in the consolidated statements of operations as follows:

	Three Months Ended March 31,
	2019		2018
	(unaudited) (in thousands)
Cost of revenues	$	558	$	362
Research and development	2,678		2,105
Sales and marketing	3,443		3,101
General and administrative	2,282		1,359
Total	$	8,961	$	6,927