Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Cash denominated in foreign currencies	$ 0	$ (4,275,539)
Cash denominated in foreign currencies, proceeds	4,184,850	$ 4,184,850
Uncertain tax position	$ 0
Open tax year	2015 2016 2017 2018