DISCONTINUED OPERATIONS - Mortgage Servicing Rights (Details) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) Loan
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of loans held under MSR portfolio | Loan			973
Unpaid principal amount on servicing assets			$ 4,900,000
Servicing Asset at Fair Value, Amount [Roll Forward]
Changes in fair value	$ (6,457)	$ (6,955)
Change in fair value of ACRE Capital's MSRs outstanding due to increase (decrease) in weighted average discount rate			$ 2,000
GSE / HUD
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of loans held under MSR portfolio | Loan			953
Unpaid principal amount on servicing assets			$ 4,300,000
Other loans
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of loans held under MSR portfolio | Loan			20
Unpaid principal amount on servicing assets			$ 554,800
ACRE Capital Sale | Discontinued Operations, Held-for-sale
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	61,800	58,889	58,889
MSRs purchased	323
Additions, following sale of loan	10,275	10,050
Changes in fair value	(6,457)	(6,955)
Prepayments and write-offs	(3,058)	(1,836)
MSRs disposed of in the ACRE Capital Sale	(62,883)
Ending balance	$ 0	$ 60,148	$ 61,800