INVESTMENTS IN SERVICER ADVANCES - Summary of Investments in Servicer Advances - Additional Information (Footnote) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Investments in and Advances to Affiliates [Line Items]
Investments	$ 12,884,846	$ 7,718,821
Servicer Advance Joint Venture [Member] | Servicer Advances [Member]
Investments in and Advances to Affiliates [Line Items]
Gross LTV, if sold	93.40%
Net LTV, if sold	92.40%
Gross LTV, including deferred servicing fees	86.90%
Net LTV, including deferred servicing fees	85.90%
Non-Agency Bonds [Member]
Investments in and Advances to Affiliates [Line Items]
Investments	$ 0
Non-Agency Bonds [Member] | Servicer Advance Joint Venture [Member] | Servicer Advances [Member]
Investments in and Advances to Affiliates [Line Items]
Investments	$ 175,800