Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Stock-based Compensation Expense

Stock-based compensation expense was recorded in the following cost and expense categories consistent with the respective employee or service provider’s related cash compensation (in thousands):

 

	Three months ended March 31,
	2018		2017
Cost of revenue
Subscription and support	$	171	$	140
Professional services	150		100
Operating expenses
Research and development	1,021		493
Sales and marketing	1,113		659
General and administrative	3,450		2,747
Total	$	5,905	$	4,139

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The fair value of our stock options and ESPP purchase rights was estimated assuming no expected dividends and the following weighted-average assumptions: 

	Three months ended March 31,
	2018	2017
Stock Options
Expected term (in years)	—	6.0 - 6.1
Risk-free interest rate	—%	2.10%
Expected volatility	—%	39.9% - 43.8%
ESPP
Expected term (in years)	0.5	—
Risk-free interest rate	1.8%	—%
Expected volatility	22.2%	—%

Schedule of Share-based Payment Award, ESPP, Valuation Assumptions

The fair value of our stock options and ESPP purchase rights was estimated assuming no expected dividends and the following weighted-average assumptions: 

	Three months ended March 31,
	2018	2017
Stock Options
Expected term (in years)	—	6.0 - 6.1
Risk-free interest rate	—%	2.10%
Expected volatility	—%	39.9% - 43.8%
ESPP
Expected term (in years)	0.5	—
Risk-free interest rate	1.8%	—%
Expected volatility	22.2%	—%

Schedule of Stock-Option Activity

The following table summarizes the option activity under the Plans for the three months ended March 31, 2018: 

	Options	Weighted- Average  Exercise  Price		Weighted- Average  Remaining  Contractual  Term (Years)	Aggregate Intrinsic Value
					(in thousands)
Outstanding at December 31, 2017	8,145,777	$	13.33	7.0	$	65,913
Granted	—	—
Forfeited	(42,110)	18.30
Exercised	(296,061)	10.39
Outstanding at March 31, 2018	7,807,606	$	13.42	6.8	$	80,299
Exercisable at March 31, 2018	5,026,156	$	11.95	5.9	$	59,037

Schedule of Restricted Stock Shares

The following table summarizes the restricted stock award activity under the Plan for the three months ended March 31, 2018:

	Number of Shares	Weighted-Average Grant Date Fair Value
Unvested at December 31, 2017	163,332	$	13.40
Granted	—	—
Forfeited	—	—
Vested	(163,332)	13.40
Unvested at March 31, 2018	—	$	—

Schedule of Restricted Stock Units

The following table summarizes the restricted stock unit activity under the Plan for the three months ended March 31, 2018:

	Number of Shares	Weighted-Average Grant Date Fair Value
Unvested at December 31, 2017	574,072	$	14.51
Granted	1,552,187	22.24
Forfeited	(2,592)	21.25
Vested(1)	(206,619)	14.34
Unvested at March 31, 2018	1,917,048	$	20.78

(1) As of March 31, 2018, recipients of 388,747 shares had elected to defer settlement of the vested restricted stock units in accordance with our Nonqualified Deferred Compensation Plan.