Asset-Backed Securities Issued - Additional Information (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Debt Instrument [Line Items]
Description of interest rate				Substantially all ABS issued pay variable rates of interest, which are indexed to one-, three-, or six-month LIBOR.
ABS issued principal	[1],[2]	$ 1,262,122		$ 1,262,122		$ 1,545,119
Asset-backed Securities
Debt Instrument [Line Items]
ABS issued principal		1,262,122		1,262,122		1,545,119
Amortization of deferred ABS issuance costs, less than		1,000	$ 1,000	1,000	$ 1,000
Asset-backed Securities | Contractual maturities of over five years
Debt Instrument [Line Items]
ABS issued principal		1,250,000		$ 1,250,000
Contractual maturities of ABS (in years)				5 years
Asset-backed Securities | Maturity Less Than One Year
Debt Instrument [Line Items]
ABS issued principal		8,000		$ 8,000
Contractual maturities of ABS, maximum (in years)				1 year
Asset-backed Securities | Certificates With Principal Value
Debt Instrument [Line Items]
Principal value		1,377,818		$ 1,377,818		$ 1,555,413
Asset-backed Securities | Certificates With Principal Value | Contractual maturities of over five years
Debt Instrument [Line Items]
Principal value		1,360,000		1,360,000
Asset-backed Securities | Certificates With Principal Value | Maturity Less Than One Year
Debt Instrument [Line Items]
Principal value		$ 16,000		$ 16,000

[1] On January 1, 2015, we adopted ASU 2014-13 and began to account for residential loans held-for-investment and asset backed securities issued at consolidated Sequoia entities (which are VIEs) at fair value. At December 31, 2014, amounts presented in residential loans held-for-investment for these assets included $1,474,386 at historical cost. See Note 3 for further discussion.

[2] Our consolidated balance sheets include assets of consolidated variable interest entities (“VIEs”) that can only be used to settle obligations of these VIEs and liabilities of consolidated VIEs for which creditors do not have recourse to the primary beneficiary (Redwood Trust, Inc.). At June 30, 2015 and December 31, 2014, assets of consolidated VIEs totaled $1,622,636 and $1,900,208, respectively, and liabilities of consolidated VIEs totaled $1,263,249 and $1,546,490, respectively. See Note 4 for further discussion.