XML 88 R76.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Real Estate Securities - Available for Sale Securities by Collateral Type (Details) - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017
--- | --- | ---
Investment Holdings [Line Items] |  |
Available-for-sale securities | $ 361,841 | $ 507,666
Senior IO Securities |  |
Investment Holdings [Line Items] |  |
Available-for-sale securities | 114,628 | 179,864
Subordinate Securities | Mezzanine |  |
Investment Holdings [Line Items] |  |
Available-for-sale securities | 36,377 | 92,002
Subordinate Securities | Subordinate |  |
Investment Holdings [Line Items] |  |
Available-for-sale securities | $ 210,836 | $ 235,800

X
- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References No definition available. + 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: | 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: |