Stockholders' Equity - Schedule of Reserve for Authorized but Unissued Shares of Common Stock (Detail)	Dec. 31, 2019 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares reserved for issuance (in shares)	6,307,915
Common stock options and restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares reserved for issuance (in shares)	3,334,130
Common stock employee purchase plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares reserved for issuance (in shares)	2,973,785