Summary of Redwood's Interest in Third-Party Variable Interest Entity's (Detail) (Real Estate Securities, USD $) In Thousands, unless otherwise specified	Jun. 30, 2013
Variable Interest Entity [Line Items]
Assets	$ 1,019,533
Senior Securities
Variable Interest Entity [Line Items]
Assets	481,190
Re-REMIC
Variable Interest Entity [Line Items]
Assets	154,167
Subordinate Securities
Variable Interest Entity [Line Items]
Assets	$ 384,176

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://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph a

-URI http://asc.fasb.org/extlink&oid=28200181&loc=d3e5728-111685

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