XML 99 R83.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Real Estate Securities - Summary of Significant Valuation Assumptions for Available for Sale Securities (Details) - Prime | 12 Months Ended
--- | ---
Dec. 31, 2017
Minimum |
Schedule of Available-for-sale Securities [Line Items] |
Prepayment rates | 8.00%
Projected losses | 0.22%
Maximum |
Schedule of Available-for-sale Securities [Line Items] |
Prepayment rates | 20.00%
Projected losses | 5.00%

X
- Definition This item represents a significant valuation assumption on prepayment rates, represented as a percentage, which was considered as one of the potential factors in reaching a conclusion that the available-for-sale investments are not other-than-temporarily impaired. + References No definition available. + Details
Name: | rwt_AvailableForSaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosurePrepaymentRates
Namespace Prefix: | rwt_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition This item represents the default rate of the underlying assets in the security that were considered as one of the potential factors in reaching a conclusion that the available-for-sale investments are not other-than-temporarily impaired. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563 + Details
Name: | us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureOtherDefaultRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
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_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |