Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended	9 Months Ended
	Mar. 25, 2020	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum percentage of fair market value of common stock		100.00%	100.00%
Aggregate intrinsic value, options exercised			$ 43	$ 184
Options granted, weighted average grant date fair value (in usd per share)			$ 6.93	$ 11.33
Share based compensation, restricted stock units granted (in shares)			681,081
Employee Stock Option | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period (in years)			10 years
Incentive Stock Options And Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares based compensation, vested period (in years)			4 years
Non-Statutory Options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares based compensation, vested period (in years)			4 years
Non-Statutory Options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares based compensation, vested period (in years)			3 years
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost of stock based awards		$ 9,100	$ 9,100
Unrecognized compensation cost of stock based awards, recognition period			2 years 3 months 18 days
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted		678,581
2017 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Offering period (months)			6 months
Shares of common stock issued (in shares)			10,057
2015 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ordinary share issued (in shares)		969,340	969,340
2017 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for issuance		30,000	30,000
Proposed Amendment to the 2017 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of number of common stock outstanding	4.00%
Additional shares authorized (in shares)	474,465
2019 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ordinary share issued (in shares)		650,000	650,000
Shares reserved for issuance		290,000	290,000