XML 107 R95.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Asset-Backed Securities Issued - Additional Information (Details) | 9 Months Ended
--- | ---
Sep. 30, 2018
Asset-backed securities issued | Contractual maturities of over five years |
Debt Instrument [Line Items] |
Contractual maturities of ABS (in years) | 5 years

X
- Definition Long Term Marketable Securities Maturities Term + References No definition available. + Details
Name: | rwt_LongTermMarketableSecuritiesMaturitiesTerm
Namespace Prefix: | rwt_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DebtInstrumentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentSecondaryCategorizationAxis=rwt_MaturityOverFiveYearsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |