Commitments and Contingencies - Additional Information (Detail) - 9 months ended Sep. 30, 2019	USD ($)	SGD ($)
Commitments And Contingencies Disclosure [Line Items]
Lease expiration date	Apr. 30, 2023
Operating Lease option to extend	The Company’s option to extend for an additional five-year term.
Non-cancelable minimum purchase commitments	$ 1,600,000
License Agreement [Member]
Commitments And Contingencies Disclosure [Line Items]
License agreement expiration terms	The license agreement will expire on a country-by-country basis until the last to expire of the patents and patent applications covering such licensed product or service. The Licensors may terminate the license agreement within 60 days after written notice in the event of a breach of contract. The Licensors may also terminate the agreement upon written notice in the event of the Company’s bankruptcy, liquidation, or insolvency. In addition, the Company has the right to terminate this agreement in its entirety at will upon 90 days’ advance written notice to the Licensors. However, if the Company has commenced the commercialization of licensed products, the Company can only terminate at will if it ceases all development and commercialization of licensed products.
Eighth Year Anniversary and Thereafter [Member] | License Agreement [Member]
Commitments And Contingencies Disclosure [Line Items]
License maintenance fees	$ 100,000
Maximum [Member] | License Agreement [Member]
Commitments And Contingencies Disclosure [Line Items]
Contingent contractual obligation	4,000,000	$ 5,500,000
Maximum [Member] | First Seven Year Anniversary [Member] | License Agreement [Member]
Commitments And Contingencies Disclosure [Line Items]
License maintenance fees	100,000
Non-current restricted cash [Member] | Letter of Credit [Member]
Commitments And Contingencies Disclosure [Line Items]
Lease security	$ 1,300,000