Property and Equipment, Net - Additional Information (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Depreciation and amortization expense	$ 139,000
Proceeds from property and equipment	66,000
Gain (loss) on disposal of property and equipment	66,000
Accumulated depreciation	612,000	$ 522,000
Fully Depreciated Assets [Member]
Property Plant And Equipment [Line Items]
Disposal of property and equipment	45,000	723,000
Proceeds from property and equipment	66,000	0
Gain (loss) on disposal of property and equipment	$ 66,000
Not Fully Depreciated Assets [Member]
Property Plant And Equipment [Line Items]
Disposal of property and equipment		26,000
Proceeds from property and equipment		0
Gain (loss) on disposal of property and equipment		(5,000)
Accumulated depreciation		$ 21,000