Investments (Details) - Table - AFS Securities (Unrealized Losses) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
AFS Securities
Estimated Fair Value: Within 12 Months	$ 1,524	$ 564
Estimated Fair Value: 12 Months or More	316	504
Estimated Fair Value: Total	1,840	1,068
Unrealized Losses: Within 12 Months	(6)	(1)
Unrealized Losses: 12 Months or More	(17)	(16)
Unrealized Losses: Total	(23)	(17)
U.S. Treasury obligations
AFS Securities
Estimated Fair Value: Within 12 Months	1,090	348
Estimated Fair Value: 12 Months or More	124	124
Estimated Fair Value: Total	1,214	472
Unrealized Losses: Within 12 Months	(1)	0
Unrealized Losses: 12 Months or More	0	0
Unrealized Losses: Total	(1)	0
State housing agency obligations:
AFS Securities
Estimated Fair Value: Within 12 Months	36	14
Estimated Fair Value: 12 Months or More	0	0
Estimated Fair Value: Total	36	14
Unrealized Losses: Within 12 Months	(1)	0
Unrealized Losses: 12 Months or More	0	0
Unrealized Losses: Total	(1)	0
MBS - GSEs
AFS Securities
Estimated Fair Value: Within 12 Months	158	28
Estimated Fair Value: 12 Months or More	0	150
Estimated Fair Value: Total	158	178
Unrealized Losses: Within 12 Months	(1)	0
Unrealized Losses: 12 Months or More	0	0
Unrealized Losses: Total	(1)	0
PLRMBS
AFS Securities
Estimated Fair Value: Within 12 Months	240	174
Estimated Fair Value: 12 Months or More	192	230
Estimated Fair Value: Total	432	404
Unrealized Losses: Within 12 Months	(3)	(1)
Unrealized Losses: 12 Months or More	(17)	(16)
Unrealized Losses: Total	$ (20)	$ (17)

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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