Segment Information - Supplemental Information by Segment (Details) - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Real estate securities	[1]	$ 351,335	$ 1,099,874
Other investments	[1]	384,628	358,130
Goodwill and intangible assets	[1]	60,737	161,464
Total Assets	[1]	10,402,412	17,995,440
Residential loans
Segment Reporting Information [Line Items]
Loans, at fair value		4,494,936	7,714,850
Business purpose residential loans
Segment Reporting Information [Line Items]
Loans, at fair value		3,956,101	3,506,743
Multifamily loans
Segment Reporting Information [Line Items]
Loans, at fair value		491,415	4,408,524
Operating Segments | Residential Lending
Segment Reporting Information [Line Items]
Real estate securities		146,608	229,074
Other investments		14,878	42,224
Goodwill and intangible assets		0	0
Total Assets		2,148,643	5,410,540
Operating Segments | Residential Lending | Residential loans
Segment Reporting Information [Line Items]
Loans, at fair value		1,941,489	4,939,745
Operating Segments | Residential Lending | Business purpose residential loans
Segment Reporting Information [Line Items]
Loans, at fair value		0	0
Operating Segments | Residential Lending | Multifamily loans
Segment Reporting Information [Line Items]
Loans, at fair value		0	0
Operating Segments | Business Purpose Lending
Segment Reporting Information [Line Items]
Real estate securities		0	0
Other investments		25,713	21,002
Goodwill and intangible assets		60,737	161,464
Total Assets		4,134,913	3,786,641
Operating Segments | Business Purpose Lending | Residential loans
Segment Reporting Information [Line Items]
Loans, at fair value		0	0
Operating Segments | Business Purpose Lending | Business purpose residential loans
Segment Reporting Information [Line Items]
Loans, at fair value		3,956,101	3,506,743
Operating Segments | Business Purpose Lending | Multifamily loans
Segment Reporting Information [Line Items]
Loans, at fair value		0	0
Operating Segments | Third-Party Investments
Segment Reporting Information [Line Items]
Real estate securities		204,727	870,800
Other investments		344,037	294,904
Goodwill and intangible assets		0	0
Total Assets		3,315,039	8,028,946
Operating Segments | Third-Party Investments | Residential loans
Segment Reporting Information [Line Items]
Loans, at fair value		2,256,682	2,367,215
Operating Segments | Third-Party Investments | Business purpose residential loans
Segment Reporting Information [Line Items]
Loans, at fair value		0	0
Operating Segments | Third-Party Investments | Multifamily loans
Segment Reporting Information [Line Items]
Loans, at fair value		491,415	4,408,524
Corporate/ Other
Segment Reporting Information [Line Items]
Real estate securities		0	0
Other investments		0	0
Goodwill and intangible assets		0	0
Total Assets		803,817	769,313
Corporate/ Other | Residential loans
Segment Reporting Information [Line Items]
Loans, at fair value		296,765	407,890
Corporate/ Other | Business purpose residential loans
Segment Reporting Information [Line Items]
Loans, at fair value		0	0
Corporate/ Other | Multifamily loans
Segment Reporting Information [Line Items]
Loans, at fair value		$ 0	$ 0

[1] 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 Redwood Trust, Inc. or its affiliates. At September 30, 2020 and December 31, 2019, assets of consolidated VIEs totaled $8,197,095 and $11,931,869, respectively. At September 30, 2020 and December 31, 2019, liabilities of consolidated VIEs totaled $7,238,047 and $10,717,072, respectively. See Note 4 for further discussion.