| REAL ESTATE SECURITIES - Real Estate Securities Holdings (Details) (USD $) In Thousands, unless otherwise specified | 9 Months Ended | |||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sep. 30, 2014 | Dec. 31, 2013 | Sep. 30, 2014
 CMBS Conduit [Member]
 Securities | Sep. 30, 2014
 CMBS Single Borrower [Member]
 Securities | Sep. 30, 2014
 CMBS Large Loan [Member]
 Securities | Sep. 30, 2014
 REIT Debt [Member]
 Securities | Sep. 30, 2014
 Non-Agency RMBS [Member]
 Securities | Sep. 30, 2014
 ABS Franchise [Member]
 Securities | Sep. 30, 2014
 CDO Securities [Member]
 Securities | Sep. 30, 2014
 Debt Securities [Member]
 Securities | Sep. 30, 2014
 Equity Securities [Member]
 Securities | Sep. 30, 2014
 Real Estate Securities [Member]
 Securities | |||||||||||||||||||||||||||
| Outstanding Face Amount | $ 157,778 | $ 79,396 | $ 3,229 | $ 29,200 | [1] | $ 87,113 | [1] | $ 8,464 | [1] | $ 21,377 | [1],[2] | $ 386,557 | [3] | $ 386,557 | [1] | |||||||||||||||||||||||
| Before Impairment - Amortized Cost Basis | 161,688 | 79,044 | 3,229 | 28,856 | 97,879 | 7,647 | 6,394 | 384,737 | 384,737 | |||||||||||||||||||||||||||||
| Other Than Temporary Impairment - Amortized Cost Basis | (63,210) | (12,364) | (59,987) | (7,647) | (143,208) | (143,208) | ||||||||||||||||||||||||||||||||
| Amortized Cost Basis After Impairment | 98,478 | 66,680 | 3,229 | 28,856 | [4] | 37,892 | [4] | 6,394 | [2],[4] | 241,529 | 241,529 | [4] | ||||||||||||||||||||||||||
| Gains - gross unrealized | 34,030 | 3,672 | 1,437 | 22,339 | 7,327 | 68,805 | 309 | 69,114 | ||||||||||||||||||||||||||||||
| Losses - gross unrealized | (4) | (4) | (4) | |||||||||||||||||||||||||||||||||||
| Carrying Value | $ 310,639 | $ 984,263 | $ 132,508 | [5] | $ 70,348 | [5] | $ 3,229 | [5] | $ 30,293 | [5] | $ 60,231 | [5] | $ 13,721 | [2],[5] | $ 310,330 | [5] | $ 309 | [5] | $ 310,639 | [5] | ||||||||||||||||||
| Number of securities | 26 | 12 | 1 | 5 | 33 | 1 | 3 | 81 | 1 | 82 | ||||||||||||||||||||||||||||
| Weighted Average Rating | B+ | [6] | BB- | [6] | BBB- | [6] | BB+ | [6] | CCC+ | [6] | C | [6] | B- | [6] | B | [6] | ||||||||||||||||||||||
| Weighted Average Coupon | 5.52% | 6.33% | 3.36% | 5.89% | 1.04% | 6.69% | 1.10% | 4.47% | ||||||||||||||||||||||||||||||
| Weighted Average Yield | 12.08% | 7.25% | 3.36% | 6.88% | 10.75% | 10.11% | 9.75% | |||||||||||||||||||||||||||||||
| Weighted Average Life (Years) | 2 years 3 months 18 days | [7] | 2 years 3 months 18 days | [7] | 0 years 2 months 12 days | [7] | 0 years 9 months 18 days | [7] | 6 years 2 months 12 days | [7] | 7 years 8 months 12 days | [7] | 3 years 3 months 18 days | [7] | ||||||||||||||||||||||||
| Weighted Average Principal Subordination | 12.40% | [8] | 2.20% | [8] | 4.40% | [8] | 26.80% | [8] | 0.00% | [8] | 27.10% | [8] | ||||||||||||||||||||||||||
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