Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(a))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_AccountsPayableCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Accounts Payable - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accounts Payable [Line Items]
Accounts Payable, Current	$ 813	$ 52
Other Payables [Member]
Accounts Payable [Line Items]
Accounts Payable, Current	100
Preclinical Expenses [Member]
Accounts Payable [Line Items]
Accounts Payable, Current	200
License Maintenance Fee [Member]
Accounts Payable [Line Items]
Accounts Payable, Current	100
Manufacturing Costs [Member]
Accounts Payable [Line Items]
Accounts Payable, Current	100
Clinical Research Organizations [Member]
Accounts Payable [Line Items]
Accounts Payable, Current	$ 300