Equity and Employee Stock Plans (Tables)

9 Months Ended

Sep. 30, 2019

Share-based Payment Arrangement [Abstract]

Schedule of Reserved Shares of Common Stock

The Company has reserved shares of common stock, on an as-converted basis, for future issuance as follows:

	September 30, 2019	December 31, 2018
Equity Incentive Plans
Shares underlying outstanding stock options	8,102,171	9,435,349
Shares underlying outstanding restricted stock units	4,536,677	3,264,702
Shares available for future equity grants	7,837,918	5,068,013
Total shares reserved for issuance	20,476,766	17,768,064

2017 Employee Stock Purchase Plan
Shares available for issuance on January 1, 2019 and 2018, respectively	2,890,973		2,414,688
Shares issued since January 1, 2019 and 2018, respectively	(262,110	)	(425,228	)
Total shares available for future issuance	2,628,863		1,989,460

Schedule of Stock Option Activity

The following table summarizes activity for stock options for the nine months ended September 30, 2019:

	Number Of Options	Weighted- Average Exercise Price		Weighted-Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value
Outstanding as of December 31, 2018	9,435,349	$	6.48	6.06	$	74,669
Options granted	150,000	27.50
Options exercised	(1,397,074)	5.49
Options forfeited	(81,826)	9.16
Options canceled	(4,278)	8.22
Outstanding as of September 30, 2019	8,102,171	7.01		5.59	81,204
Options exercisable as of September 30, 2019	7,100,240	6.30		5.32	74,839

Schedule of Nonvested Restricted Stock Units Activity

The following table summarizes activity for restricted stock units for the nine months ended September 30, 2019:

	Restricted Stock Units		Weighted-Average Grant Date Fair Value
Unvested outstanding as of December 31, 2018	3,264,702		$	19.68
Granted	2,102,975		17.79
Vested	(562,755	)	21.00
Forfeited	(268,245	)	20.06
Unvested outstanding as of September 30, 2019	4,536,677		18.62

Schedule of Allocation of Share-based Compensation Costs

The following table details, for each period indicated, (i) the Company's stock-based compensation net of forfeitures, and the amount capitalized in internally developed software and (ii) includes changes to the probability of achieving outstanding performance-based equity awards, each as included in the Company’s condensed consolidated statements of operations:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2019		2018		2019		2018
Cost of revenue	$	1,605	$	1,370	$	4,398	$	4,061
Technology and development	3,320		2,135		8,661		5,335
Marketing	390		155		1,025		431
General and administrative	2,195		1,838		5,708		4,646
Total stock-based compensation	$	7,510	$	5,498	$	19,792	$	14,473