CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Allowance for doubtful accounts	$ 600	$ 600
Class A Common Stock
Common stock, par value (in usd per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	34,525,386	29,626,054
Common stock, shares outstanding (in shares)	34,525,386	29,626,054
Class B Common Stock
Common stock, par value (in usd per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	32,942,636	34,290,383
Common stock, shares outstanding (in shares)	32,942,636	34,290,383