Segment Information - Supplemental Information by Segment (Details) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Real estate securities	[1]	$ 1,099,874	$ 1,452,494
Other investments	[1]	358,130	438,518
Goodwill		161,464
Total Assets	[1]	17,995,440	11,937,406
Residential loans
Segment Reporting Information [Line Items]
Loans, at fair value		7,714,850	7,254,742
Business purpose residential loans
Segment Reporting Information [Line Items]
Loans, at fair value		3,506,743	141,258
Multifamily loans
Segment Reporting Information [Line Items]
Loans, at fair value		4,408,524	2,144,598
Operating Segments | Residential Lending
Segment Reporting Information [Line Items]
Real estate securities		229,074	364,308
Other investments		42,224	99,984
Goodwill		0
Total Assets		5,410,540	6,186,889
Operating Segments | Residential Lending | Residential loans
Segment Reporting Information [Line Items]
Loans, at fair value		4,939,745	5,512,116
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		21,002	10,754
Goodwill		161,464
Total Assets		3,786,641	160,950
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		3,506,743	141,258
Operating Segments | Business Purpose Lending | Multifamily loans
Segment Reporting Information [Line Items]
Loans, at fair value		0	0
Operating Segments | Multifamily Investments
Segment Reporting Information [Line Items]
Real estate securities		404,128	429,079
Other investments		61,018	15,092
Goodwill		0
Total Assets		4,889,330	2,600,150
Operating Segments | Multifamily Investments | Residential loans
Segment Reporting Information [Line Items]
Loans, at fair value		0	0
Operating Segments | Multifamily Investments | Business purpose residential loans
Segment Reporting Information [Line Items]
Loans, at fair value		0	0
Operating Segments | Multifamily Investments | Multifamily loans
Segment Reporting Information [Line Items]
Loans, at fair value		4,408,524	2,144,598
Operating Segments | Third-Party Residential Investments
Segment Reporting Information [Line Items]
Real estate securities		466,672	659,107
Other investments		233,886	312,688
Goodwill		0
Total Assets		3,139,616	2,232,276
Operating Segments | Third-Party Residential Investments | Residential loans
Segment Reporting Information [Line Items]
Loans, at fair value		2,367,215	1,222,668
Operating Segments | Third-Party Residential Investments | Business purpose residential loans
Segment Reporting Information [Line Items]
Loans, at fair value		0	0
Operating Segments | Third-Party Residential Investments | Multifamily loans
Segment Reporting Information [Line Items]
Loans, at fair value		0	0
Corporate/ Other
Segment Reporting Information [Line Items]
Real estate securities		0	0
Other investments		0	0
Goodwill		0
Total Assets		769,313	757,141
Corporate/ Other | Residential loans
Segment Reporting Information [Line Items]
Loans, at fair value		407,890	519,958
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 December 31, 2019 and December 31, 2018, assets of consolidated VIEs totaled $11,931,869 and $6,331,191, respectively. At December 31, 2019 and December 31, 2018, liabilities of consolidated VIEs totaled $10,717,072 and $5,709,807, respectively. See Note 4 for further discussion.