Residential Loans - Quarterly Activity of Residential Loans Held-for-Sale (Details) - Residential Loans - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Principal balance of loans acquired	$ 3,484,633	$ 57,743	$ 6,580,681	$ 2,687,651
Principal balance of loans sold	3,324,919	2,280,076	5,600,751	4,936,795
Net market valuation gains (losses) recorded	$ 26,278	$ (2,014)	$ 49,707	$ (15,494)

For each line item in the statement of financial position, the amounts of gains and losses from fair value changes included in earnings.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123596393&loc=d3e14172-108612

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Period Type:	duration