Summary of Redwood's Interest in Third-Party VIEs (Detail) (Real Estate Securities, USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2011 Entity
Variable Interest Entity [Line Items]
Assets	$ 761,074
Number of VIEs	307
Senior Securities
Variable Interest Entity [Line Items]
Assets	593,350
Number of VIEs	95
Re-REMIC
Variable Interest Entity [Line Items]
Assets	77,575
Number of VIEs	7
Subordinate
Variable Interest Entity [Line Items]
Assets	82,881
Number of VIEs	186
Commercial
Variable Interest Entity [Line Items]
Assets	5,865
Number of VIEs	10
CDO
Variable Interest Entity [Line Items]
Assets	$ 1,403
Number of VIEs	9