Fair Value Disclosures - Difference between Fair Value and UPB for Certain Financial Instruments with Fair Value Option Elected (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Fair Value, Option, Quantitative Disclosures [Line Items]
Debt, Fair Value	$ 189	$ 195
Held by Freddie Mac
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Aggregate Differences, Loans and Long-term Receivables	3	3
Debt, Fair Value	49	51
Debt, Unpaid Principal Balance, with Fair Value Option Elected	46	48
Held by consolidated trusts
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Aggregate Differences, Loans and Long-term Receivables	(85)	(58)
Debt issued by cons trusts, Fair Value	5,441	5,387
Debt, Unpaid Principal Balance, with Fair Value Option Elected	5,526	5,445
Interest-Only \| Held by consolidated trusts
Fair Value, Option, Quantitative Disclosures [Line Items]
Debt, Fair Value	700	600
Mortgage loans held-for-investment
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans Held For Investment Fair Value Disclosure	6,906	7,005
Fair Value, Option, Aggregate Differences, Loans and Long-term Receivables	(167)	(143)
Loans, Unpaid Principal Balance, with Fair Value Elected	$ 7,073	$ 7,148

Debt issued by Cons Trusts, Fair Value

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- Definition

It represents loans held for investment fair value disclosure

+ References

No definition available.

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- Definition

Represents Loans, Unpaid Principal Balance, with Fair Value Elected

+ References

No definition available.

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- Definition

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

+ References

No definition available.

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- 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

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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.

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- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

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