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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Numerator:
Net income (loss) attributable to holders of shares of Class A common stock—basic	$ 29,459	$ 35,690	$ 43,029	$ 69,015
Class A Common Stock
Numerator:
Net income (loss) attributable to holders of shares of Class A common stock—basic	29,459	35,690	43,029	69,015
Add (deduct) dilutive effect of:
Net income (loss) attributable to holders of shares of Class A common stock—diluted	$ 29,459	$ 35,690	$ 43,029	$ 69,015
Denominator:
Weighted average shares of Class A common stock outstanding—basic	50,107,269	41,750,396	48,919,127	38,938,952
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	4,560,818	7,529,711	5,851,725	8,052,469
Weighted average shares of Class A common stock outstanding—diluted	54,668,087	49,280,107	54,770,852	46,991,421
Net income (loss) per share attributable to holders of shares of Class A common stock
Basic (in dollars per share)	$ 0.59	$ 0.85	$ 0.88	$ 1.77
Diluted (in dollars per share)	$ 0.54	$ 0.72	$ 0.79	$ 1.47