Fair Value Disclosures - Assets and Liabilities on Our Consolidated Balance Sheets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Mortgage Loans [Abstract]
Mortgage loans held-for-sale	$ 0	$ 11,394
Mortgage loans FVO held-for-investment	7,005	2,413
Other assets:
Netting Adjustment	(2,998)	(3,906)
Total other assets	6,421	5,870
Liabilities, Fair Value Disclosure [Abstract]
Debt issued by consolidated trusts Fair Value	5,841	2,013
Long-Term Debt, Fair Value	195	326
Other liabilities:
Derivative Liabilities, netting adjustment	(2,998)	(3,906)
Other liabilities, fair value	781	978
Held by Freddie Mac
Liabilities, Fair Value Disclosure [Abstract]
Long-Term Debt, Fair Value	51	152
Fair Value, Measurements, Recurring
Debt Securities, Available-for-sale [Abstract]
Available-for-sale	3,316	3,899
Debt Securities, Trading, and Equity Securities, FV-NI, Cost [Abstract]
Trading securities, at fair value	82,096	51,872
Total investments in securities	85,412	55,771
Mortgage Loans [Abstract]
Mortgage loans held-for-sale		11,394
Mortgage loans FVO held-for-investment	7,005	2,413
Other assets:
Guarantee Assets Fair Value Disclosure	4,728	5,126
Derivative Asset, Fair Value	1,466	501
All Other Assets Fair Value Disclosure	227	243
Netting Adjustment	(3,874)	(5,989)
Total other assets	6,421	5,870
Total assets carried at fair value on a recurring basis	98,838	75,448
Liabilities, Fair Value Disclosure [Abstract]
Debt issued by consolidated trusts Fair Value	5,841	2,013
Long-Term Debt, Fair Value	195	326
Other liabilities:
Derivative liabilities at fair value	781	954
Other liabilities		24
Derivative Liabilities, netting adjustment	(3,979)	(6,282)
Other liabilities, fair value		978
Total liabilities carried at fair value on a recurring basis	6,817	3,317
Fair Value, Measurements, Recurring | Mortage-related securities
Debt Securities, Trading, and Equity Securities, FV-NI, Cost [Abstract]
Trading securities, at fair value	10,932	9,158
Fair Value, Measurements, Recurring | Non-mortgage-related securities
Debt Securities, Trading, and Equity Securities, FV-NI, Cost [Abstract]
Trading securities, at fair value	71,164	42,714
Fair Value, Measurements, Recurring | Level 1
Debt Securities, Available-for-sale [Abstract]
Available-for-sale	0	0
Debt Securities, Trading, and Equity Securities, FV-NI, Cost [Abstract]
Trading securities, at fair value	70,916	42,289
Total investments in securities	70,916	42,289
Mortgage Loans [Abstract]
Mortgage loans held-for-sale		0
Mortgage loans FVO held-for-investment	0	0
Other assets:
Guarantee Assets Fair Value Disclosure	0	0
Derivative Asset, Fair Value	5	9
All Other Assets Fair Value Disclosure	0	0
Total other assets	5	9
Total assets carried at fair value on a recurring basis	70,921	42,298
Liabilities, Fair Value Disclosure [Abstract]
Long-Term Debt, Fair Value	0	0
Other liabilities:
Derivative liabilities at fair value	0	0
Other liabilities		0
Other liabilities, fair value		0
Total liabilities carried at fair value on a recurring basis	0	0
Fair Value, Measurements, Recurring | Level 1 | Held by consolidated trusts
Liabilities, Fair Value Disclosure [Abstract]
Debt issued by consolidated trusts Fair Value	0	0
Fair Value, Measurements, Recurring | Level 1 | Mortage-related securities
Debt Securities, Trading, and Equity Securities, FV-NI, Cost [Abstract]
Trading securities, at fair value	0	0
Fair Value, Measurements, Recurring | Level 1 | Non-mortgage-related securities
Debt Securities, Trading, and Equity Securities, FV-NI, Cost [Abstract]
Trading securities, at fair value	70,916	42,289
Fair Value, Measurements, Recurring | Level 2
Debt Securities, Available-for-sale [Abstract]
Available-for-sale	2,616	3,316
Debt Securities, Trading, and Equity Securities, FV-NI, Cost [Abstract]
Trading securities, at fair value	8,394	6,556
Total investments in securities	11,010	9,872
Mortgage Loans [Abstract]
Mortgage loans held-for-sale		10,099
Mortgage loans FVO held-for-investment	5,587	1,572
Other assets:
Guarantee Assets Fair Value Disclosure	0	0
Derivative Asset, Fair Value	5,261	6,387
All Other Assets Fair Value Disclosure	0	24
Total other assets	5,261	6,411
Total assets carried at fair value on a recurring basis	21,858	27,954
Other liabilities:
Derivative liabilities at fair value	4,708	7,116
Other liabilities		5
Other liabilities, fair value		7,121
Total liabilities carried at fair value on a recurring basis	10,641	9,358
Fair Value, Measurements, Recurring | Level 2 | Held by consolidated trusts
Liabilities, Fair Value Disclosure [Abstract]
Debt issued by consolidated trusts Fair Value	5,808	1,996
Fair Value, Measurements, Recurring | Level 2 | Held by Freddie Mac
Liabilities, Fair Value Disclosure [Abstract]
Long-Term Debt, Fair Value	125	241
Fair Value, Measurements, Recurring | Level 2 | Mortage-related securities
Debt Securities, Trading, and Equity Securities, FV-NI, Cost [Abstract]
Trading securities, at fair value	8,146	6,131
Fair Value, Measurements, Recurring | Level 2 | Non-mortgage-related securities
Debt Securities, Trading, and Equity Securities, FV-NI, Cost [Abstract]
Trading securities, at fair value	248	425
Fair Value, Measurements, Recurring | Level 3
Debt Securities, Available-for-sale [Abstract]
Available-for-sale	700	583
Debt Securities, Trading, and Equity Securities, FV-NI, Cost [Abstract]
Trading securities, at fair value	2,786	3,027
Total investments in securities	3,486	3,610
Mortgage Loans [Abstract]
Mortgage loans held-for-sale		1,295
Mortgage loans FVO held-for-investment	1,418	841
Other assets:
Guarantee Assets Fair Value Disclosure	4,728	5,126
Derivative Asset, Fair Value	74	94
All Other Assets Fair Value Disclosure	227	219
Total other assets	5,029	5,439
Total assets carried at fair value on a recurring basis	9,933	11,185
Other liabilities:
Derivative liabilities at fair value	52	120
Other liabilities		19
Other liabilities, fair value		139
Total liabilities carried at fair value on a recurring basis	155	241
Fair Value, Measurements, Recurring | Level 3 | Held by consolidated trusts
Liabilities, Fair Value Disclosure [Abstract]
Debt issued by consolidated trusts Fair Value	33	17
Fair Value, Measurements, Recurring | Level 3 | Held by Freddie Mac
Liabilities, Fair Value Disclosure [Abstract]
Long-Term Debt, Fair Value	70	85
Fair Value, Measurements, Recurring | Level 3 | Mortage-related securities
Debt Securities, Trading, and Equity Securities, FV-NI, Cost [Abstract]
Trading securities, at fair value	2,786	3,027
Fair Value, Measurements, Recurring | Level 3 | Non-mortgage-related securities
Debt Securities, Trading, and Equity Securities, FV-NI, Cost [Abstract]
Trading securities, at fair value	$ 0	$ 0