INCOME TAXES - Schedule of Taxable Common Stock Distributions (Details) - $ / shares		1 Months Ended		3 Months Ended								12 Months Ended
	Dec. 20, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Dividends per share (in dollars per share)												$ 1.6	$ 1.94	$ 1.38
Ordinary Income												78.03%	66.64%	96.13%
Long-term Capital Gain												1.03%	7.83%	3.87%
Return of Capital												20.94%	25.53%	0.00%
Dividends declared per share of common stock (in dollars per share)	$ 0.50	$ 0.50	$ 0.50	$ 0.5	$ 0.5	$ 0.5	$ 0.5	$ 0.5	$ 0.5	$ 0.5	$ 0.48	$ 2	$ 1.98	$ 1.84