Organization, Liquidity and Management's Plan, and Summary of Significant Accounting Policies - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2019 USD ($) Segment	Jan. 01, 2019 USD ($)
Organization And Summary Of Significant Accounting Policies [Line Items]
Date of incorporation	Sep. 24, 2012
State of Incorporation	Delaware
Right-of-use assets	$ 730,000
Related lease liabilities	801,000
Financing leases	$ 0
Highly liquid investments maturities	Three months or less
Number of operating segment | Segment	1
ASU 2016-02 [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Right-of-use assets		$ 858,000
Related lease liabilities		$ 882,000