Investment Fair Value Changes, Net - Components of Investment Activities (Details) - Investment Fair Value Changes, Net - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Investment Holdings [Line Items]
Changes in fair value of assets	$ (870,832)	$ 20,159
Residential loans held-for-investment, at Redwood
Investment Holdings [Line Items]
Changes in fair value of assets	(93,636)	28,108
Single-family rental loans held-for-investment
Investment Holdings [Line Items]
Changes in fair value of assets	(23,028)	0
Residential bridge loans
Investment Holdings [Line Items]
Changes in fair value of assets	(38,602)	(303)
Trading securities
Investment Holdings [Line Items]
Changes in fair value of assets	(263,325)	21,860
Servicer advance investments
Investment Holdings [Line Items]
Changes in fair value of assets	(6,062)	1,008
Excess MSRs
Investment Holdings [Line Items]
Changes in fair value of assets	(9,494)	(437)
Shared home appreciation options
Investment Holdings [Line Items]
Changes in fair value of assets	(7,554)	0
REO
Investment Holdings [Line Items]
Changes in fair value of assets	(498)	0
Net investments in Legacy Sequoia entities
Investment Holdings [Line Items]
Changes in fair value of assets	(391)	(374)
Net investments in Sequoia Choice entities
Investment Holdings [Line Items]
Changes in fair value of assets	(69,669)	3,265
Net investments in Freddie Mac SLST entities
Investment Holdings [Line Items]
Changes in fair value of assets	(142,162)	6,365
Net investments in Freddie Mac K-Series entities
Investment Holdings [Line Items]
Changes in fair value of assets	(86,509)	3,119
Net investments in CAFL entities
Investment Holdings [Line Items]
Changes in fair value of assets	(67,846)	0
Risk-sharing and other investments
Investment Holdings [Line Items]
Changes in fair value of assets	(1,389)	(77)
Risk management derivatives, net
Investment Holdings [Line Items]
Changes in fair value of assets	(59,142)	(42,375)
Credit losses on AFS securities
Investment Holdings [Line Items]
Changes in fair value of assets	$ (1,525)	$ 0