Net Income (Loss) Per Share Attributable to Class A Common Shareholders - Schedule of Calculations of Basic and Diluted Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Numerator:
Net income (loss) attributable to holders of shares of Class A common stock—basic	$ 40,615	$ 32,449	$ 83,644	$ 101,464
Class A Common Stock
Numerator:
Net income (loss) attributable to holders of shares of Class A common stock—basic	40,615	32,449	83,644	101,464
Add (deduct) dilutive effect of:
Net income (loss) attributable to holders of shares of Class A common stock—diluted	$ 40,615	$ 32,449	$ 83,644	$ 101,464
Denominator:
Weighted average shares of Class A common stock outstanding—basic	51,079,746	45,203,781	49,796,867	41,211,843
Add (deduct) dilutive effect of:
Weighted average number of incremental shares issuable from unvested restricted stock, RSUs and stock options, as calculated using the treasury stock method	4,388,982	7,937,417	5,348,381	7,962,061
Weighted average shares of Class A common stock outstanding—diluted	55,468,728	53,141,198	55,145,248	49,173,904
Net income (loss) per share attributable to holders of shares of Class A common stock
Basic (in dollars per share)	$ 0.80	$ 0.72	$ 1.68	$ 2.46
Diluted (in dollars per share)	$ 0.73	$ 0.61	$ 1.52	$ 2.06