Stock-Based Compensation Expense and Employee Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2021

Compensation Related Costs [Abstract]

Schedule of Employee and Non-Employee Stock-Based Compensation Expense

The following table summarizes the components of stock-based compensation expense in the condensed consolidated statements of operations (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Cost of revenue	$	3,804	$	4,736	$	6,803	$	10,243
Research and development	5,291		4,714		10,199		10,810
Sales and marketing	4,010		2,234		8,095		6,124
General and administrative	6,028		6,947		11,246		14,473
	$	19,133	$	18,631	$	36,343	$	41,650

Schedule of Stock Option and RSU Activity

The following table summarizes the stock option activity under our stock plans during the reporting period:

	Outstanding Options
	Number of Shares	Weighted Average Exercise Price		Remaining Contractual Life (Years)	Aggregate Intrinsic Value
					(in thousands)
Balances at December 31, 2020	15,354,271	$	21.27	6.0	$	129,855
Granted	—
Exercised	(2,470,262)	24.67
Cancelled	(630,306)	13.58
Balances at June 30, 2021	12,253,703	20.98		5.8	96,586
Vested and expected to vest at June 30, 2021	12,046,166	21.18		5.8	92,978
Exercisable at June 30, 2021	8,619,596	25.28		5.1	37,719

The following table presents the stock activity and the total number of shares available for grant under our stock plans as of June 30, 2021:

	Plan Shares Available for Grant
Balances at December 31, 2020	20,233,754
Added to plan	7,675,984
Granted	(5,147,681)
Cancelled	1,376,014
Expired	(171,843)
Balances at June 30, 2021	23,966,228

Schedule of RSU Activity and Related Information

A summary of our stock awards activity and related information is as follows:

	Number of Awards Outstanding	Weighted Average Grant Date Fair Value
Unvested Balance at December 31, 2020	6,418,788	$	13.71
Granted	5,147,861	24.56
Vested	(1,951,664)	16.94
Forfeited	(745,708)	13.43
Unvested Balance at June 30, 2021	8,869,277	19.32