Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Accumulated amortization	$ 127,229	$ 117,605
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Class A common stock [Member]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	240,000,000	240,000,000
Common stock, shares issued	45,950,716	45,855,000
Common stock, shares outstanding	45,950,716	45,855,000
Class C common stock [Member]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares issued	40,000,000	40,000,000
Common stock, shares outstanding	40,000,000	40,000,000