Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2018

Stockholders' Equity Note [Abstract]

Share-based Compensation, Stock Options, Activity

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

	Nine Months Ended September 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	(689,227	)	$	13.843
Forfeited	(1,471	)	$	21.972
Options outstanding as of September 30, 2018	765,587		$	18.257	$	42,102	4.800
Options exercisable at the end of the period	722,216		$	18.054	$	39,900	4.682

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

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

Range of exercise price				Options outstanding as of September 30, 2018	Weighted average remaining contractual life (years)	Weighted average exercise price		Options exercisable as of September 30, 2018	Weighted average remaining contractual life (years)	Weighted average exercise price of options exercisable
$	1.256	—	1.576	130,625	0.914	$	1.282	130,625	0.914	$	1.282
$	6.230	—	8.800	12,356	3.259	$	8.039	12,356	3.259	$	8.039
$	12.470	—	16.870	157,613	5.201	$	13.936	139,903	4.924	$	13.463
$	19.510	—	21.660	240,699	5.825	$	21.190	230,416	5.806	$	21.191
$	22.010	—	24.230	98,380	5.427	$	22.404	98,380	5.427	$	22.404
		$29.880		75,936	6.397	$	29.880	60,558	6.397	$	29.880
		$39.860		49,978	5.477	$	39.860	49,978	5.477	$	39.860
				765,587	4.800	$	18.257	722,216	4.682	$	18.054

Schedule of Stockholders' Equity Note, Warrants or Rights

The Company’s outstanding options granted to consultants for services as of September 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	4,000	$	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	6,693	$	21.660	6,296	November 2024
May 2015	1,137	$	19.510	805	May 2025
February 2016	2,138	$	16.870	1,250	February 2026
	24,718			23,101

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 nine months ended September 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	1,220,624		$	53.56
Vested	(553,671	)	$	26.28
Forfeited	(121,351	)	$	37.04
Unvested balance – September 30, 2018	2,563,723		$	38.81

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 September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
	(unaudited) (in thousands)				(unaudited) (in thousands)
Cost of revenues	$	470	$	283	$	1,300	$	783
Research and development	2,097		1,374		7,180		3,805
Sales and marketing	3,600		1,856		10,349		6,277
General and administrative	2,232		1,269		5,345		3,580
Total	$	8,399	$	4,782	$	24,174	$	14,445