Principles of Consolidation - Summary of Unconsolidated Variable Interest Entity's Sponsored by Redwood (Details) - Variable Interest Entity, Not Primary Beneficiary - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
On-balance sheet assets, at fair value:
Maximum loss exposure	$ 334,734	$ 588,396
Principal balance of loans outstanding	6,870,398	7,318,167
Principal balance of loans 30 days delinquent	21,427	18,300
Interest-only, senior and subordinate securities, classified as trading
On-balance sheet assets, at fair value:
Securities	41,909	258,697
Subordinate securities, classified as AFS
On-balance sheet assets, at fair value:
Securities	234,025	272,715
MSRs
On-balance sheet assets, at fair value:
Securities	$ 58,800	$ 56,984