INVESTMENTS IN REAL ESTATE SECURITIES - Summary of Activity Related to Credit Losses on Debt Securities (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Beginning balance of credit losses on debt securities for which a portion of an OTTI was recognized in other comprehensive income	$ 1,127
Increases to credit losses on securities for which an OTTI was previously recognized and a portion of an OTTI was recognized in other comprehensive income	6
Additions for credit losses on securities for which an OTTI was not previously recognized	1,065
Reductions for securities for which the amount previously recognized in other comprehensive income was recognized in earnings because the entity intends to sell the security or more likely than not will be required to sell the security before recovery of its amortized cost basis	0
Reduction for credit losses on securities for which no OTTI was recognized in other comprehensive income at the current measurement date	0
Reduction for securities sold during the period	(228)
Ending balance of credit losses on debt securities for which a portion of an OTTI was recognized in other comprehensive income	$ 1,970