EQUITY STRUCTURE AND ACCOUNTS - Dividends Declared (Details) - $ / shares															3 Months Ended								12 Months Ended
	Dec. 15, 2020	Aug. 31, 2020	May 28, 2020	Feb. 27, 2020	Nov. 26, 2019	Aug. 22, 2019	May 30, 2019	Feb. 27, 2019	Jan. 24, 2019	Nov. 01, 2018	Oct. 30, 2018	Sep. 05, 2018	May 30, 2018	Feb. 27, 2018	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Class A Common Stock
Class of Stock [Line Items]
Dividends per share of Class A common stock (in dollars per share)	$ 0.200	$ 0.200	$ 0.200	$ 0.340	$ 0.340	$ 0.340	$ 0.340	$ 0.340	$ 0.570	$ 0.570	$ 0.570	$ 0.325	$ 0.325	$ 0.315	$ 0.200	$ 0.200	$ 0.200	$ 0.340	$ 0.340	$ 0.340	$ 0.340	$ 0.340	$ 0.940	$ 1.360	$ 1.535