Equity Incentive Plans (Tables)

12 Months Ended

Dec. 31, 2017

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock Option Activity Under 2007 Plan, 2011 Plan and 2016 Plan

Stock option activity under the 2016 Plan, 2011 Plan and the 2007 Plan during the year ended December 31, 2017 was as follows (in thousands, except per share and contractual life data):

						Weighted-
				Weighted-		Average
				Average		Remaining		Total
	Options			Exercise Price		Contractual		Intrinsic
	Outstanding			per Share		Life (years)		Value
Outstanding at December 31, 2016		11,203		$	9.49
Options granted		451			16.97
Options exercised		(3,339	)		6.56
Options forfeited or canceled		(825	)		13.84
Outstanding at December 31, 2017		7,490		$	10.76		6.41	$	95,553
Vested and expected to vest at December 31, 2017		7,410		$	10.71		6.39	$	94,925
Exercisable at December 31, 2017		4,935		$	8.74		5.53	$	72,930

Schedule of Fair Value of Stock Option Granted Estimated the Date of Granting Using Black-Scholes Option Pricing Model

The fair value of stock options granted was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions:

	Years Ended December 31,
	2017		2016		2015
Dividend yield		0.0%		0.0%		0.0%
Risk-free interest rate	1.8% - 2.1%		1.1% - 2.1%		1.3% - 2.0%
Expected life	4.1 - 5.6		5.6 - 7.9		5.0 - 6.1
Expected volatility	33.3% - 35.4%		37.4% - 42.4%		38.9% - 47.0%

Summary of RSU Activity Under 2016 Plan

RSU activity under the 2016 Plan during the year ended December 31, 2017 was as follows (in thousands, except per share data):

				Weighted-Average
	RSUs			Grant Date Fair Value
	Outstanding			per Share
Non-Vested outstanding at December 31, 2016		628		$	16.43
Granted		1,741			15.97
Vested		(128	)		16.46
Forfeited or canceled		(211	)		15.27
Non-Vested outstanding at December 31, 2017		2,030		$	16.15

Schedule of Fair Value of Common Shares to be Issued Under the 2016 ESPP

There were 311,742 shares of Class A common stock issued under the 2016 ESPP. For the years ended December 31, 2017 and 2016, the fair value of common shares to be issued under the 2016 ESPP was estimated using the Black-Scholes option pricing model with the following assumptions:

	Years Ended December 31,
	2017		2016
Dividend yield	0.0%		0.0%
Risk-free interest rate	1.07% - 1.45%		0.6%
Expected life		0.50		0.56
Expected volatility	27.0% - 44.3%		33.9%

Summary of Stock Based Compensation Expenses

Stock-based compensation expense recognized in the Company’s statement of comprehensive loss was as follows (in thousands):

	Years Ended December 31,
	2017		2016		2015
Cost of revenue
Subscription	$	1,218	$	891	$	482
Professional services		1,131		820		738
Operating expenses
Research and development		4,491		2,977		2,283
Sales and marketing		4,614		3,132		2,477
General and administrative		4,616		2,639		1,835
Total stock-based compensation	$	16,070	$	10,459	$	7,815