Stock-Based Compensation - Summary of ESPP Share Activity (Detail) - shares		9 Months Ended
Jan. 01, 2021	Sep. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Available for future purchases, September 30, 2021 (in shares)		2,297,290
2019 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional shares reserved (in shares)	86,490
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Available for future purchases, January 1, 2021 (in shares)	369,771	369,771
Purchases (in shares)		(87,473)
Available for future purchases, September 30, 2021 (in shares)		368,788
Employee Stock Purchase Plan \| 2019 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional shares reserved (in shares)		86,490

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Number of shares issued during the period as a result of an employee stock purchase plan.

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