INVESTMENTS IN RESIDENTIAL MORTGAGE LOANS - Summary of Activities Related to the Valuation Provision on Reverse Mortgage Loans and Allowance for Loan Losses on Performing Loans (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013
Reverse Mortgage Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning, balance	$ 461		$ 0
Allowance for loan losses	1,111	[1]	461	[1]
Charge-offs	0	[2],[3]	0	[2]
Reversal of valuation provision on loans transferred to other assets	(54)		0
Ending, balance	1,518		461
Performing Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning, balance	0		0
Allowance for loan losses	1,811	[1]	0	[1]
Charge-offs	(364)	[2],[3]	0	[2]
Reversal of valuation provision on loans transferred to other assets	0		0
Ending, balance	$ 1,447		$ 0

[1] Based on an analysis of collective borrower performance, credit ratings of borrowers, loan-to-value ratios, estimated value of the underlying collateral, key terms of the loans and historical and anticipated trends in defaults and loss severities at a pool level.

[2] Loans, other than PCI loans, are generally charged off or charged down to the net realizable value of the collateral (i.e., fair value less costs to sell), with an offset to the allowance for loan losses, when available information confirms that loans are uncollectible.

[3] Represents a charge-off upon transfer to held-for-sale.