Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2018

Stockholders' Equity Note [Abstract]

Share-based Compensation, Stock Options, Activity

A summary of employees’ stock options activities during the six months ended June 30, 2018 is as follows:

	Six Months Ended June 30, 2018 (unaudited)
	Number		Weighted average exercise price		Aggregate intrinsic value (in thousands)		Weighted average remaining contractual life (years)
Options outstanding as of January 1, 2018	1,456,285		$	16.172	$	47,152	4.906
Granted	—		$	—
Exercised	(611,220	)	$	12.970
Forfeited	(1,234	)	$	22.070
Options outstanding as of June 30, 2018	843,831		$	18.483	$	47,269	5.073
Options exercisable at the end of the period	765,242		$	18.041	$	43,205	4.897

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

The options outstanding as of June 30, 2018 (unaudited) have been separated into ranges of exercise price as follows:

Range of exercise price				Options outstanding as of June 30, 2018	Weighted average remaining contractual life (years)	Weighted average exercise price		Options exercisable as of June 30, 2018	Weighted average remaining contractual life (years)	Weighted average exercise price of options exercisable
$	1.256	—	1.576	136,060	1.035	$	1.286	136,060	1.035	$	1.286
$	6.230	—	8.800	19,156	3.513	$	7.608	19,156	3.513	$	7.608
$	12.470	—	16.870	170,613	5.397	$	13.833	149,779	5.084	$	13.289
$	19.510	—	21.660	271,325	6.126	$	21.207	238,181	6.095	$	21.201
$	22.010	—	24.230	105,467	5.779	$	22.402	105,467	5.779	$	22.402
		$29.880		77,695	6.649	$	29.880	53,084	6.649	$	29.880
		$39.860		63,515	5.729	$	39.860	63,515	5.729	$	39.860
				843,831	5.073	$	18.483	765,242	4.897	$	18.088

Schedule of Stockholders' Equity Note, Warrants or Rights

The Company’s outstanding options granted to consultants for services as of June 30, 2018 (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	4,188	$	21.140	4,188	August 2023
March 2014	7,300	$	39.860	7,300	March 2024
May 2014	5,000	$	22.010	5,000	May 2024
November 2014	6,768	$	21.660	5,765	November 2024
May 2015	1,200	$	19.510	742	May 2025
February 2016	2,180	$	16.870	1,137	February 2026
	28,136			25,632

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

A summary of restricted stock units for employees, consultants and non-employee directors of the Company for the six months ended June 30, 2018 (unaudited) is as follows:

	Number of shares underlying outstanding restricted stock units		Weighted- average grant date fair value
Unvested balance - January 1, 2018	2,018,121		$	27.32
Granted	1,131,424		$	52.97
Vested	(484,615	)	$	25.11
Forfeited	(73,252	)	$	34.91
Unvested balance – June 30, 2018	2,591,678		$	38.72

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 June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
	(unaudited) (in thousands)				(unaudited) (in thousands)
Cost of revenues	$	468	$	273	$	830	$	500
Research and development	2,978		1,301		5,083		2,431
Sales and marketing	3,648		2,362		6,749		4,421
General and administrative	1,754		1,323		3,113		2,311
Total	$	8,848	$	5,259	$	15,775	$	9,663