Fair Value Disclosures - Difference between Fair Value and UPB for Certain Financial Instruments with Fair Value Option Elected (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025
Held by Freddie Mac
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Aggregate Differences, Loans and Long-term Receivables	$ 1	$ 3
Long-Term Debt, Fair Value, with Fair Value Option Elected	37	51
Debt, Unpaid Principal Balance, with Fair Value Option Elected	36	48
Held by consolidated trusts
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Aggregate Differences, Loans and Long-term Receivables	(271)	(58)
Debt issued by cons trusts, Fair Value	5,179	5,387
Debt, Unpaid Principal Balance, with Fair Value Option Elected	5,450	5,445
Interest-Only \| Held by consolidated trusts
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-Term Debt, Fair Value, with Fair Value Option Elected	700	600
Mortgage loans held-for-investment
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans Held For Investment Fair Value Disclosure	6,298	7,005
Fair Value, Option, Aggregate Differences, Loans and Long-term Receivables	(482)	(143)
Loans, Unpaid Principal Balance, with Fair Value Elected	$ 6,780	$ 7,148

Debt issued by Cons Trusts, Fair Value

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

It represents loans held for investment fair value disclosure

+ References

No definition available.

+ Details

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Namespace Prefix:	fmcc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents Loans, Unpaid Principal Balance, with Fair Value Elected

+ References

No definition available.

+ Details

Name:	fmcc_LoansUnpaidPrincipalBalanceWithFairValueElected
Namespace Prefix:	fmcc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents fair value of long-term debt with fair value option elected.

+ References

No definition available.

+ Details

Name:	fmcc_LongTermDebtFairValueWithFairValueOptionElected
Namespace Prefix:	fmcc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents unpaid principal balance of loans with fair value option elected.

+ References

No definition available.

+ Details

Name:	fmcc_LongTermDebtUnpaidPrincipalBalanceWithFairValueOptionElected
Namespace Prefix:	fmcc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

This item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of loans and long-term receivables (other than securities categorized as trading, available-for-sale or held-to-maturity) that have contractual principal amounts and for which the fair value option has been elected.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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/2003/role/exampleRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482881/825-10-55-10

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 825
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482881/825-10-55-12

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
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-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-32

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-Topic 825
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-Name Accounting Standards Codification
-Section 50
-Paragraph 28
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

+ Details

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- Details

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- Details

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- Details

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