Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 2018

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

Stock option activity under the equity incentive plans was as follows:



	Stock Options Outstanding
	Number of Shares Subject to Stock Options		Weighted– Average Exercise Price		Aggregate Intrinsic Value ⁽¹⁾
	(in thousands)				(in thousands)
Balance—December 31, 2017	21,386		$	3.01
Granted	—		—
Exercised	(565	)	1.76
Forfeited or canceled	(134	)	4.76
Balance—March 31, 2018	20,687		3.03		$	50,820

Stock options vested and expected to vest—March 31, 2018	20,638		3.03		50,763
Stock options exercisable—March 31, 2018	17,145		$	2.62	$	47,238

⁽¹⁾ The aggregate intrinsic values of stock options outstanding, exercisable, vested and expected to vest as of March 31, 2018 were calculated as the difference between the exercise price of the stock options and the fair value of the Class A common stock of $5.10 as of March 31, 2018.

Schedule of restricted stock unit activity

RSU activity under the equity incentive plans was as follows:



	RSUs Outstanding		Weighted- Average Grant Date Fair Value
	(in thousands)
Unvested balance—December 31, 2017	19,188		$	9.13
Granted	10,199		5.20
Vested	(2,624	)	8.75
Forfeited or canceled	(1,119	)	8.94
Unvested balance—March 31, 2018	25,644		$	7.61

Schedule of stock-based compensation expense

Total stock-based compensation expense recognized was as follows (in thousands):



	Three Months Ended
	March 31, 2018		April 1, 2017

Cost of revenue	$	1,098	$	18
Research and development	14,671		14,685
Sales and marketing	3,447		3,635
General and administrative	4,425		4,155
Total stock-based compensation expense	$	23,641	$	22,493