Principles of Consolidation - Summary of Unconsolidated Variable Interest Entity's Sponsored by Redwood (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
On-balance sheet assets, at fair value:
Subordinate securities, classified as AFS	$ 134,980	$ 132,146
Total Subordinate Investment Securities
On-balance sheet assets, at fair value:
Subordinate securities, classified as AFS	134,980	132,146
Variable Interest Entity, Not Primary Beneficiary
On-balance sheet assets, at fair value:
Maximum loss exposure	120,082	114,678
Assets transferred:
Principal balance of loans outstanding	3,991,357	4,052,922
Principal balance of loans 30+ days delinquent	21,906	27,739
Variable Interest Entity, Not Primary Beneficiary | Total Subordinate Investment Securities
On-balance sheet assets, at fair value:
Subordinate securities, classified as AFS	77,714	74,367
Interest-only, senior and subordinate securities, classified as trading | Variable Interest Entity, Not Primary Beneficiary
On-balance sheet assets, at fair value:
Interest-only, senior and subordinate securities, classified as trading	31,208	28,722
Mortgage servicing rights
On-balance sheet assets, at fair value:
Mortgage servicing rights	24,831	25,421
Mortgage servicing rights | Variable Interest Entity, Not Primary Beneficiary
On-balance sheet assets, at fair value:
Mortgage servicing rights	$ 11,160	$ 11,589