EQUITY STRUCTURE AND ACCOUNTS - Dividends Declared (Details) - $ / shares								3 Months Ended		9 Months Ended
	Sep. 01, 2016	Jun. 01, 2016	Mar. 01, 2016	Jan. 21, 2016	Sep. 01, 2015	Jun. 08, 2015	Mar. 12, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Class A common stock
Class of Stock [Line Items]
Dividends per share of common stock (in dollars per share)	$ 0.275	$ 0.275	$ 0.275	$ 1.45	$ 0.275	$ 0.25	$ 0.25	$ 0.275	$ 0.275	$ 0.825	$ 0.775