Fair Value of Financial Instruments - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands		Jun. 30, 2020	Dec. 31, 2019
Assets
Trading securities		$ 142,699	$ 860,540
Available-for-sale securities		173,737	239,334
MSRs		249,705	151,582
Derivative assets	[1]	357	35,701
Pledged collateral		33,105	32,945
Liabilities
Contingent consideration		14,953	28,484
Derivative liabilities	[1]	1,932	163,424
Fair Value, Measurements, Recurring
Assets
Business purpose residential loans		3,782,200	3,506,743
Multifamily loans		489,075	4,408,524
Trading securities		142,699	860,540
Available-for-sale securities		173,737	239,334
Servicer advance investments		266,948	169,204
MSRs		19,661	42,224
Excess MSRs		36,197	31,814
Shared home appreciation options		40,851	45,085
Derivative assets		357	35,701
Pledged collateral		33,105	32,945
FHLBC stock		5,000	43,393
Guarantee asset		770	1,686
Liabilities
Contingent consideration			28,484
Derivative liabilities		1,932	163,424
ABS issued		6,856,086	10,515,475
Fair Value, Measurements, Recurring | Residential Loans
Assets
Residential loans		4,534,229	7,714,745
Fair Value, Measurements, Recurring | Level 1
Assets
Business purpose residential loans		0	0
Multifamily loans		0	0
Trading securities		0	0
Available-for-sale securities		0	0
Servicer advance investments		0	0
MSRs		0	0
Excess MSRs		0	0
Shared home appreciation options		0	0
Derivative assets		0	6,531
Pledged collateral		33,105	32,945
FHLBC stock		0	0
Guarantee asset		0	0
Liabilities
Contingent consideration			0
Derivative liabilities		0	13,368
ABS issued		0	0
Fair Value, Measurements, Recurring | Level 1 | Residential Loans
Assets
Residential loans		0	0
Fair Value, Measurements, Recurring | Level 2
Assets
Business purpose residential loans		0	0
Multifamily loans		0	0
Trading securities		0	0
Available-for-sale securities		0	0
Servicer advance investments		0	0
MSRs		0	0
Excess MSRs		0	0
Shared home appreciation options		0	0
Derivative assets		0	19,020
Pledged collateral		0	0
FHLBC stock		5,000	43,393
Guarantee asset		0	0
Liabilities
Contingent consideration			0
Derivative liabilities		0	148,766
ABS issued		0	0
Fair Value, Measurements, Recurring | Level 2 | Residential Loans
Assets
Residential loans		0	0
Fair Value, Measurements, Recurring | Level 3
Assets
Business purpose residential loans		3,782,200	3,506,743
Multifamily loans		489,075	4,408,524
Trading securities		142,699	860,540
Available-for-sale securities		173,737	239,334
Servicer advance investments		266,948	169,204
MSRs		19,661	42,224
Excess MSRs		36,197	31,814
Shared home appreciation options		40,851	45,085
Derivative assets		357	10,150
Pledged collateral		0	0
FHLBC stock		0	0
Guarantee asset		770	1,686
Liabilities
Contingent consideration			28,484
Derivative liabilities		1,932	1,290
ABS issued		6,856,086	10,515,475
Fair Value, Measurements, Recurring | Level 3 | Residential Loans
Assets
Residential loans		4,534,229	7,714,745
Fair Value
Assets
Trading securities		142,699	860,540
Available-for-sale securities		173,737	239,334
Derivative assets		357	35,701
Pledged collateral		33,105	32,945
FHLBC stock		5,000	43,393
Guarantee asset		770	1,686
Liabilities
Contingent consideration		14,953	28,484
Derivative liabilities		1,932	163,424
ABS issued		6,856,086	10,515,475
Carrying Value
Assets
Trading securities		142,699	860,540
Available-for-sale securities		173,737	239,334
Derivative assets		357	35,701
Pledged collateral		33,105	32,945
FHLBC stock		5,000	43,393
Guarantee asset		770	1,686
Liabilities
Contingent consideration		14,953	28,484
Derivative liabilities		1,932	163,424
ABS issued		$ 6,856,086	$ 10,515,475

[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 June 30, 2020 and December 31, 2019, assets of consolidated VIEs totaled $7,984,618 and $11,931,869, respectively. At June 30, 2020 and December 31, 2019, liabilities of consolidated VIEs totaled $7,140,221 and $10,717,072, respectively. See Note 4 for further discussion.