Fair Value of Financial Instruments - Carrying Values and Estimated Fair Values of Assets and Liabilities (Details) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018
Assets
Trading securities		$ 860,540	$ 1,118,612
Available-for-sale securities		239,334	333,882
Shared home appreciation options		0	39,703
Derivative assets	[1]	35,701	35,789
Pledged collateral		32,945	42,433
Liabilities
Contingent consideration		28,484	0
Derivative liabilities	[1]	163,424	84,855
Residential Loans
Assets
MSR Fair Value		169,204	300,468
Carrying Value
Assets
Trading securities		860,540	1,118,612
Available-for-sale securities		239,334	333,882
Shared home appreciation options		45,085	0
Cash and cash equivalents		196,966	175,764
Restricted cash		93,867	29,313
Accrued interest receivable		71,058	47,105
Derivative assets		35,701	35,789
Margin receivable		209,776	100,773
FHLBC stock		43,393	43,393
Guarantee asset		1,686	2,618
Pledged collateral		32,945	42,433
Liabilities
Accrued interest payable		60,655	42,528
Margin payable		1,700	835
Guarantee obligation		14,009	16,711
Contingent consideration			0
Derivative liabilities		163,424	84,855
ABS issued at fair value		10,515,475	5,410,073
FHLBC long-term borrowings		1,999,999	1,999,999
Subordinate securities financing facility		183,520	0
Convertible notes, net		631,125	633,196
Trust preferred securities and subordinated notes, net		138,628	138,582
Carrying Value | Servicer advance investments
Assets
MSR Fair Value		169,204	300,468
Carrying Value | MSRs
Assets
MSR Fair Value		42,224	60,281
Carrying Value | Participation In Loan Warehouse Facility
Assets
Loans, held-for-investment		0	39,703
Carrying Value | Excess MSRs
Assets
Other assets		31,814	27,312
Carrying Value | REO
Assets
Other assets		9,462	3,943
Carrying Value | Credit facilities
Liabilities
Short-term debt facilities		2,176,591	1,937,920
Carrying Value | Servicer advance financing
Liabilities
Short-term debt facilities		152,554	262,740
Carrying Value | Residential Loans | Residential loans, held-for-sale at fair value
Assets
Loans, held-for-sale		536,385	1,048,801
Carrying Value | Residential Loans | Residential loans, held-for-investment
Assets
Loans, held-for-investment		7,178,465	6,205,941
Carrying Value | Residential Loans | Business purpose residential loans, held-for-sale, at fair value
Assets
Loans, held-for-sale		331,565	28,460
Loans, held-for-investment		3,175,178	112,798
Carrying Value | Residential Loans | Multifamily loans
Assets
Loans, held-for-investment		4,408,524	2,144,598
Fair Value
Assets
Trading securities		860,540	1,118,612
Available-for-sale securities		239,334	333,882
Shared home appreciation options		45,085	0
Cash and cash equivalents		196,966	175,764
Restricted cash		93,867	29,313
Accrued interest receivable		71,058	47,105
Derivative assets		35,701	35,789
Margin receivable		209,776	100,773
FHLBC stock		43,393	43,393
Guarantee asset		1,686	2,618
Pledged collateral		32,945	42,433
Liabilities
Accrued interest payable		60,655	42,528
Margin payable		1,700	835
Guarantee obligation		13,754	16,774
Contingent consideration		28,484	0
Derivative liabilities		163,424	84,855
ABS issued at fair value		10,515,475	5,410,073
FHLBC long-term borrowings		1,999,999	1,999,999
Subordinate securities financing facility		184,666	0
Convertible notes, net		661,985	618,271
Trust preferred securities and subordinated notes, net		99,045	102,533
Fair Value | Servicer advance investments
Assets
MSR Fair Value		169,204	300,468
Fair Value | MSRs
Assets
MSR Fair Value		42,224	60,281
Fair Value | Participation In Loan Warehouse Facility
Assets
Loans, held-for-investment		0	39,703
Fair Value | Excess MSRs
Assets
Other assets		31,814	27,312
Fair Value | REO
Assets
Other assets		10,389	4,396
Fair Value | Credit facilities
Liabilities
Short-term debt facilities		2,176,591	1,937,920
Fair Value | Servicer advance financing
Liabilities
Short-term debt facilities		152,554	262,740
Fair Value | Residential Loans | Residential loans, held-for-sale at fair value
Assets
Loans, held-for-sale		536,509	1,048,821
Fair Value | Residential Loans | Residential loans, held-for-investment
Assets
Loans, held-for-investment		7,178,465	6,205,941
Fair Value | Residential Loans | Business purpose residential loans, held-for-sale, at fair value
Assets
Loans, held-for-sale		331,565	28,460
Loans, held-for-investment		3,175,178	112,798
Fair Value | Residential Loans | Multifamily loans
Assets
Loans, held-for-investment		$ 4,408,524	$ 2,144,598

[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.