Commitments and Contingencies (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2021	Dec. 31, 2020
Related party mortgage originator (with flow mortgage loan purchase and sale agreement) [Member] \| Non-Exchange Traded Equity Investment in Mortgage Originators [Member]
Other Commitments [Line Items]
Maximum guarantees	$ 25.0
Drawn down amount being guaranteed	10.4	$ 5.3
Residential mortgage loans
Other Commitments [Line Items]
Unfunded commitment	29.4	4.7
Residential mortgage loans \| Investment in unconsolidated entities
Other Commitments [Line Items]
Unfunded commitment	639.9
Total Purchase Commitment	650.0
Corporate loan [Member]
Other Commitments [Line Items]
Unfunded commitment		$ 0.1
Corporate loan [Member] \| Line of Credit
Other Commitments [Line Items]
Unfunded commitment	$ 0.9
Line of Credit Facility, Affiliated Borrower	1.0 million

Amount of borrowings outstanding under related party's MRA for which the Company has guaranteed repayment.

No definition available.

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- Definition

Total Purchase Commitment

+ References

No definition available.

+ Details

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- Definition

Amount of unfunded commitment at period end.

+ References

No definition available.

+ Details

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- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=124440162&loc=d3e12069-110248

+ Details

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- Definition

Identification of each affiliate who is permitted to utilize the line of credit (for example, a subsidiary of the reporting entity) and description of its relationship to the reporting entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
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-Paragraph 1
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+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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