Principles of Consolidation - Summary of Redwood's Interest in Third-Party Variable Interest Entity's (Details) - Real estate securities $ in Thousands	Dec. 31, 2019 USD ($)
Variable Interest Entity [Line Items]
Assets	$ 887,015
Residential
Variable Interest Entity [Line Items]
Assets	870,799
Senior IO Securities
Variable Interest Entity [Line Items]
Assets	127,094
Mezzanine
Variable Interest Entity [Line Items]
Assets	508,195
Subordinate Securities
Variable Interest Entity [Line Items]
Assets	235,510
Excess MSRs
Variable Interest Entity [Line Items]
Assets	$ 16,216

Carrying amount of the assets in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), where the reporting entity is not the VIE's primary beneficiary.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph a
-URI http://asc.fasb.org/extlink&oid=118582676&loc=d3e5728-111685

Name:	us-gaap_VariableInterestEntityNonconsolidatedCarryingAmountAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant