Capital and Liquidity Requirements (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
Sep. 30, 2023	Dec. 31, 2022
Compliance with Regulatory Capital Requirements under Banking Regulations
Percentage of Freddie Mac's liquidity requirement of outstanding principal of TAH loans serviced	8.00%	8.00%
Outstanding borrower advances	$ 1.3	$ 1.3
Seller/Servicer Agreements
Compliance with Regulatory Capital Requirements under Banking Regulations
Amount of capital in excess of aggregate regulatory requirements	$ 412.5	$ 433.4

Outstanding borrower advances to investors.

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- Definition

Percentage of liquidity requirement of outstanding principal of targeted affordable housing loans serviced.

+ References

No definition available.

+ 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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480696/942-505-50-1B

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480696/942-505-50-1

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- Definition

Amount of total risk-based capital exceeding minimum required for capital adequacy as defined by regulatory framework.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480696/942-505-50-1

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