Income Taxes - Deferred tax expenses (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Income Taxes
Net deferred tax assets	$ 0	$ 0
Net deferred tax liabilities	$ 0	0
Percentage of tax withholding	5.00%
Amount of tax with-held	$ 284,000
Interest on tax	20,000
Gross unrecognized tax benefits at beginning of period	$ 0	$ 0