DEBT OBLIGATIONS - Schedule of Borrowing Capacity (Footnote) (Details) $ in Thousands	12 Months Ended
Dec. 31, 2015 USD ($)
Debt Instrument [Line Items]
Outstanding Face Amount	$ 11,305,998
Non-Agency Bonds [Member]
Debt Instrument [Line Items]
Outstanding Face Amount	$ 175,800
Servicer Advances [Member]
Debt Instrument [Line Items]
Unused borrowing capacity fee	0.50%

Face (par) amount of debt instrument at time of issuance.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant