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Equity-based Compensation and Equity Incentive Plans - Additional Information (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Aug. 28, 2017 shares	Aug. 31, 2015 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exchange ratio of common stock			0.5532
Weighted average grant date fair value per share of options granted to employees | $ / shares	$ 4.59	$ 6.35
Total fair value of awards vested	$ 3,900	$ 3,300
Employee unrecognized compensation expense	$ 6,800
Employee unrecognized compensation cost, period of recognition	2 years 4 months 24 days
Equity-based compensation expense	$ 4,134	4,317
Restricted Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of awards vested	100	$ 1,300
Employee unrecognized compensation expense	$ 1,200
Employee unrecognized compensation cost, period of recognition	1 year 2 months 12 days
Granted | shares	585,600	0
Equity-based compensation expense	$ 345	$ 956
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of discount for employees under ESPP	15.00%
Purchase price as a percentage of fair value under ESPP	85.00%
Plan 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock option and stock purchase rights available for grant (in shares) | shares				647,893
Percentage of shares outstanding	5.00%
2017 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock option and stock purchase rights available for grant (in shares) | shares			1,753,061
2015 and 2017 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grants | shares	676,388
Modifications in Equity Awards | Separation of Former Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation		$ 700

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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