Warrants - Summary of Income Statement Effect of Changes in Outstanding Warrants (Detail) - USD ($)		12 Months Ended
Aug. 16, 2017	Dec. 31, 2018
Class Of Warrant Or Right [Line Items]
Changes in fair value of warrants	$ (3,498,632)
Common Stock Warrants [Member]
Class Of Warrant Or Right [Line Items]
Changes in fair value of warrants		$ (9,160)
Loss on warrants exchanged		(2,688,012)
Transaction costs		(181,312)
Change in fair value of warrant liability, including gain (loss) on exchange		$ (2,878,484)

Amount of expense (income) related to adjustment to fair value of warrant liability.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section 25
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=109262497&loc=d3e20148-110875

Name:	us-gaap_FairValueAdjustmentOfWarrants
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration