Stockholders' Equity (Detail)	12 Months Ended
	Dec. 31, 2019 vote $ / shares shares	Dec. 31, 2018 $ / shares shares
Class A Common Stock
Class of Stock [Line Items]
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, par value (in usd per share) | $ / shares	$ 0.0001	$ 0.0001
Common stock, shares issued (in shares)	34,525,386	29,626,054
Common stock, shares outstanding (in shares)	34,525,386	29,626,054
Number of votes entitled to stockholders | vote	1
Conversion of stock (in shares)	1
Maximum percentage of aggregate voting power of capital stock which triggers conversion of stock	10.00%
Class B Common Stock
Class of Stock [Line Items]
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, par value (in usd per share) | $ / shares	$ 0.0001	$ 0.0001
Common stock, shares issued (in shares)	32,942,636	34,290,383
Common stock, shares outstanding (in shares)	32,942,636	34,290,383
Number of votes entitled to stockholders | vote	10