Stockholders' Equity - Additional Information (Detail) - shares	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Equity [Line Items]
Common stock, voting right	one vote for each share of common stock
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common Class A [Member]
Equity [Line Items]
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	2,863,946	2,899,165
Common stock, shares outstanding	2,863,946	2,899,165
Warrants, issued	23,000,000
Common Class B [Member]
Equity [Line Items]
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares issued	17,250,000	17,250,000
Common stock, shares outstanding	17,250,000	17,250,000