RELATED-PARTY TRANSACTIONS AND ARRANGEMENTS (Subordinated Performance Fees) (Details) - Advisors - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Cumulative noncompounded annual return	6.00%
Subordinate performance fees on event of sale of company
Related Party Transaction [Line Items]
Commissions performance and other fees percent	15.00%
Subordinate fees for listing
Related Party Transaction [Line Items]
Commissions performance and other fees percent	15.00%
Subordinated performance fees
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 0	$ 0	$ 0