Investments in Securities - Trading 1 (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	$ 71,268	$ 78,728
Amortized cost	412	487
Available-for-sale securities	388	469
Total investments in securities	71,656	79,197
Mortgage-related
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	5,102	1,098
Non-mortgage-related
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	66,166	77,630
Consolidated trusts | Mortgage-related
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	$ 265	$ 300