Equity Incentive Awards (Tables)

6 Months Ended

Jun. 30, 2018

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock Options Activity

The following table summarizes the Company’s option activity and related information:

	Number of Options (in thousands)			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (in years)		Aggregate Intrinsic Value (in thousands)
Balance at December 31, 2017		6,695		$	4.51
Options granted		1,589			6.38
Options exercised		(1,489	)		0.38
Options cancelled		(518	)		5.98
Balance at June 30, 2018		6,277		$	5.84		7.4	$	10,653
Exercisable as of June 30, 2018		2,754		$	6.93		5.8	$	5,705

Summary of Restricted Stock Units Activity

The following table summarizes the Company’s RSUs activity and related information:

	Number of Units (in thousands)			Weighted- Average Grant- Date Fair Value		Weighted- Average Remaining Contractual Term (in years)
Outstanding at December 31, 2017		2,515		$	3.24		1.6
Granted		1,076			6.03
Vested and released		(571	)		3.46
Forfeited		(424	)		4.36
Outstanding at June 30, 2018		2,596		$	4.16		1.8

Stock-Based Compensation Expense

The following table presents, by operating expense, the Company’s stock-based compensation expense:

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2018		2017		2018		2017
	(In thousands)
Research and development	$	821	$	1,395	$	3,199	$	2,637
General and administrative		5,005		848		6,056		1,502
Total stock-based compensation expense	$	5,826	$	2,243	$	9,255	$	4,139