Stock-Based Awards - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Apr. 03, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
2018 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation cost		$ 10,733
Unrecognized stock-based compensation cost, weighted-average period		2 years 3 months
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate fair value of stock options vested		$ 6,634	$ 4,493
Aggregate intrinsic value of stock options exercised		$ 208	$ 1,887	$ 1,876
Employee Stock Option | Non-Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock converted under option plan		272,343	317,957
Restricted Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate intrinsic value of restricted stock awards vested			$ 810
Number of unvested restricted common stock		0	0
2014 Plan | Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of exercise price per share of stock options to fair market value of share of common stock		100.00%
Stock options granted expiry period		10 years
Weighted average grant-date fair value per share of stock options granted		$ 2.71	$ 7.47
2018 Stock Option and Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock to be issued	1,545,454
Percentage of authorized number of shares of common stock outstanding	4.00%
Number of shares of common stock converted under option plan		5,418,113	4,414,225
2018 Stock Option and Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock shares available for further issuance		1,409,019	1,412,159
2018 Stock Option and Incentive Plan | 2018 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock to be issued	256,818	534,544
Percentage of authorized number of shares of common stock outstanding	1.00%
Number of shares of common stock issued		0	0
2014 Plan and 2018 Plan | Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted expiry period		10 years
Stock options granted vesting period		4 years