Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2019

Summary of stock option activity

		Options Outstanding
			Weighted-		Weighted-
	Options and		Average		Average
	Awards		Exercise		Remaining	Aggregate
	Available for	Number of	Price Per		Contractual	Intrinsic
	Grant	Options	Share		Life (years)	Value
						(In thousands)
Balance—December 31, 2018	764,145	1,475,299	$	7.60	7.8	$	284
Authorized	512,864
RSUs granted	(183,402)
RSUs cancelled/forfeited	22,450
Options granted	(660,852)	660,852	$	6.58
Options exercised	—	(10,416)	$	4.69		$	24
Options cancelled/forfeited	183,022	(193,832)	$	8.57
Balance—December 31, 2019	638,227	1,931,903	$	7.17	6.5	$	188
Options exercisable—December 31, 2019		961,162	$	7.11	5.4	$	187

Schedule of restricted stock unit activity

	RSUs Outstanding
		Weighted-
		Average
	Number of	Grant Date
	Restricted Stock	Fair Value Per
	Units	Share
Balance—December 31, 2018	93,560	$	8.38
Granted	183,402		6.64
Vested	(42,550)		8.04
Cancelled/forfeited	(22,450)		8.02
Balance—December 31, 2019	211,962	$	6.97

2016 Employee Stock Purchase Plan

Schedule of fair value assumptions

	Year Ended December 31,
	2019		2018
Expected volatility	39.6 – 74.2	%	59.5 – 87.8	%
Risk-free interest rate	1.67 – 2.66	%	0.94 – 2.11	%
Expected term (in years)	0.5 – 1.0		0.5 – 1.0
Dividend yield	—	%	—	%

Employees

Schedule of fair value assumptions

	Year Ended December 31,
	2019		2018
Expected volatility	65.1 – 74.4	%	51.9 – 56.6	%
Risk-free interest rate	1.46 – 2.52	%	2.64 – 2.94	%
Expected term (in years)	5.3 – 6.1		5.7 – 6.1
Dividend yield	—	%	—	%