Stock-Based Compensation Expense - Common stock reserved for future issuance (Details) - shares		Sep. 30, 2023	Dec. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares of common stock reserved		8,656,046	11,816,582
Future [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares of common stock reserved	[1]	0	3,454,064
Restricted Stock Units
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares of common stock reserved		650,682	492,862
Stock options issued and outstanding under the 2006, 2015 and 2021 plans
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares of common stock reserved		6,974,240	6,339,558
Shares Available For Future Issuance Under The 2006 ,2015 And 2021 Plans [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares of common stock reserved		416,652	865,122
The 2021 ESPP Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares of common stock reserved		614,472	664,976

[1] Based on the closing stock price of $12.67 as reported on the Nasdaq Global Market on December 30, 2022. ATM Offering As of the date of this report, a total of 2,617,964 shares of the Company's common stock, for total gross proceeds of $50.0 million (net proceeds of $47.5 million), have been issued and sold pursuant to the ATM offering, of which 428,000 shares of the Company's common stock, for net proceeds of $11.7 million, were sold during the quarter ended September 30, 2023, which was the remaining authorized value of the common stock under the ATM offering in the third quarter of 2023.