CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Allowance for doubtful accounts receivable	$ 1,430	$ 837
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000	10,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Class A Common Stock
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	300,000	300,000
Common stock, shares issued	47,398	47,159
Common stock, shares outstanding	47,398	47,159
Class B Common Stock
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	215,000	215,000
Common stock, shares issued	27,958	27,958
Common stock, shares outstanding	27,958	27,958