EARNINGS PER SHARE - Net Income and Weighted Average Shares Outstanding (Details) - USD ($) $ in Thousands	3 Months Ended		8 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings per share
Net income attributable to Class A common shareholders	$ 3,313	$ 14,656		$ 46,698	$ 39,813
Weighted average shares outstanding:
Basic (in shares)	52,922,487	49,394,399	49,101,904	51,091,977	49,101,904
Diluted (in shares)	53,348,858	97,918,235	97,750,385	51,388,851	97,750,385
Class A common stock
Earnings per share
Net income attributable to Class A common shareholders	$ 3,313	$ 14,656	$ 39,813	$ 46,698	$ 39,813
Diluted Net income available for Class A common shareholders	$ 3,313	$ 27,433	$ 72,699	$ 46,698
Weighted average shares outstanding:
Basic (in shares)	52,922,487	49,394,399	49,101,904	51,091,977
Diluted (in shares)	53,348,858	97,918,235	97,750,385	51,388,851