NET INCOME (LOSS) PER SHARE ATTRIBUTABLE TO CLASS A COMMON SHAREHOLDERS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Apr. 30, 2014
Numerator:
Net income (loss) attributable to holders of shares of Class A common stock - basic	$ 15,278	$ 6,970
Class A common stock
Numerator:
Net income (loss) attributable to holders of shares of Class A common stock - basic	15,278	6,970
Net income (loss) attributable to holders of shares of Class A common stock - diluted	$ 15,278	$ 6,970
Denominator:
Weighted average shares of Class A common stock outstanding - basic	26,160,969	20,376,718
Weighted average number of incremental shares issuable from unvested restricted stock, RSUs and stock options, as calculated using the treasury stock method	6,760,607	2,026,102
Weighted average shares of Class A common stock outstanding—diluted	32,921,576	22,402,820
Net income (loss) per share attributable to holders of shares of Class A common stock
Basic (in dollars per share)	$ 0.58	$ 0.34
Diluted (in dollars per share)	$ 0.46	$ 0.31
Number of Shares Issuable upon Exchange of Each Unit	1		1
Fully diluted shares of common stock outstanding if all Class A partnership units were to be exchanged for common stock immediately following the reorganization	62,321,050	56,273,530
Class A common stock | Restricted stock and RSUs
Net income (loss) per share attributable to holders of shares of Class A common stock
Number of antidilutive securities excluded from calculation of diluted income (loss) per share	896	37,950
Class A common stock | Stock options
Net income (loss) per share attributable to holders of shares of Class A common stock
Number of antidilutive securities excluded from calculation of diluted income (loss) per share	0	2,933,468