CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Allowance for doubtful accounts receivable (in dollars)	$ 7,159	$ 7,416
Convertible Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Convertible Preferred stock, shares authorized	1,000,000	1,000,000
Convertible Preferred stock, shares outstanding	0	0
Common Stock Class A [Member]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	1,582,359	1,582,375
Common stock, shares outstanding	1,582,359	1,582,375
Common Stock Class B [Member]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	2,861,843	2,861,843
Common stock, shares outstanding	2,861,843	2,861,843
Common Stock Class C [Member]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	2,928,906	2,928,906
Common stock, shares outstanding	2,928,906	2,928,906
Class D common stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	38,204,964	38,752,749
Common stock, shares outstanding	38,204,964	38,752,749