XML 92 R81.htm IDEA: XBRL DOCUMENT
v3.4.0.3

Real Estate Securities - Available for Sale Securities by Collateral Type (Detail) - USD ($) $ in Thousands | Mar. 31, 2016 | Dec. 31, 2015
--- | --- | ---
Investment Holdings [Line Items] |  |
Available-for-sale securities | $ 698,356 | $ 829,245
Senior Securities |  |
Investment Holdings [Line Items] |  |
Available-for-sale securities | 140,616 | 279,251
Senior Securities | Prime |  |
Investment Holdings [Line Items] |  |
Available-for-sale securities | 111,523 | 210,993
Senior Securities | Non-prime |  |
Investment Holdings [Line Items] |  |
Available-for-sale securities | 29,093 | 68,258
Re-REMIC |  |
Investment Holdings [Line Items] |  |
Available-for-sale securities | 162,970 | 165,064
Subordinate Securities |  |
Investment Holdings [Line Items] |  |
Available-for-sale securities | 394,770 | 384,930
Subordinate Securities | Non-prime |  |
Investment Holdings [Line Items] |  |
Available-for-sale securities | 1,000 | 1,000
Subordinate Securities | Prime mezzanine |  |
Investment Holdings [Line Items] |  |
Available-for-sale securities | 225,787 | 224,624
Subordinate Securities | Prime subordinate |  |
Investment Holdings [Line Items] |  |
Available-for-sale securities | $ 168,983 | $ 160,306

X
- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=51813488&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=49167202&loc=d3e26610-111562 + Details
Name: | us-gaap_AvailableForSaleSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_InvestmentHoldingsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_InvestmentTypeAxis=rwt_SeniorSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentSecuritiesClassAxis=rwt_RealEstateSecuritiesPrimeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentSecuritiesClassAxis=rwt_RealEstateSecuritiesSubprimeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=rwt_ResecuritizationOfRealEstateMortgageInvestmentSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=rwt_SubordinateSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentSecuritiesClassAxis=rwt_RealEstateSecuritiesPrimeMezzanineMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentSecuritiesClassAxis=rwt_RealEstateSecuritiesPrimeSubordinateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |