Principles of Consolidation - Cash Flows Related to Unconsolidated Variable Interest Entity's Sponsored by Redwood (Details) - Variable Interest Entity, Not Primary Beneficiary - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Variable Interest Entity [Line Items]
Proceeds from new transfers	$ 0	$ 376,126	$ 1,610,761	$ 1,138,778
MSR fees received	2,280	2,919	7,445	9,084
Funding of compensating interest, net	4	(76)	(293)	(213)
Cash flows received on retained securities	$ 5,873	$ 6,603	$ 19,242	$ 20,892