Annual report pursuant to Section 13 and 15(d)

Commitments and Contingencies - Additional Information (Detail)

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Commitments and Contingencies - Additional Information (Detail) - USD ($)
1 Months Ended 12 Months Ended
Aug. 08, 2019
Feb. 29, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Mar. 13, 2019
Jan. 16, 2019
James K. Sims              
Commitment And Contingencies [Line Items]              
Employment agreement expiration period Feb. 09, 2020            
Office Space Lease Agreement | Subsequent Event              
Commitment And Contingencies [Line Items]              
Operating lease maturity year   2025          
Additional lease payment   $ 3,200,000          
Additional lease payment one to three years   1,212,000          
Additional lease payment three to five years   1,300,000          
Additional lease payment after five years   $ 600,000          
Minimum | James K. Sims              
Commitment And Contingencies [Line Items]              
Contingent Severance cost           $ 400,000  
Minimum | President, Chief Financial Officer and Secretary and Senior Vice President              
Commitment And Contingencies [Line Items]              
Contingent Severance cost             $ 455,000
Office Space and Research Facilities Lease              
Commitment And Contingencies [Line Items]              
Operating leases, rent expense     $ 973,000 $ 912,000 $ 805,000    
Lease agreement description     The San Diego facility lease agreement included a tenant improvement allowance which provided for the landlord to pay for tenant improvements on behalf of the Company up to $515,000. Based on the terms of this landlord incentive and involvement of the Company in the construction process, the leasehold improvements purchased under the landlord incentive were determined to be property of the Company.        
Lease expiration date     Nov. 30, 2024        
Office Space and Research Facilities Lease | Maximum              
Commitment And Contingencies [Line Items]              
Payments for tenant improvements allowance     $ 515,000