Mortgage Loans - Loan Restructuring - Financial Impacts (Details) - Single-family	3 Months Ended	6 Months Ended
Jun. 30, 2026 USD ($) mo	Jun. 30, 2025 USD ($) mo	Jun. 30, 2026 USD ($) mo	Jun. 30, 2025 USD ($) mo
20- and 30-year or more, amortizing fixed-rate
Loans in Mortgage Portfolio [Line Items]
Weighted-Average Interest Rate Reduction	0.80%	0.60%	0.73%	0.61%
Weighted-Average Term Extension (in Months) \| mo	144	145	144	150
Average amount capitalized as a result of a payment delay \| $	$ 14,360	$ 13,775	$ 13,923	$ 13,061
15-year or less, amortizing fixed-rate
Loans in Mortgage Portfolio [Line Items]
Weighted-Average Interest Rate Reduction	1.10%	1.18%	1.01%	1.17%
Weighted-Average Term Extension (in Months) \| mo	53	52	53	53
Average amount capitalized as a result of a payment delay \| $	$ 10,791	$ 10,121	$ 11,043	$ 9,431
Adjustable-rate
Loans in Mortgage Portfolio [Line Items]
Weighted-Average Interest Rate Reduction	0.58%	1.31%	0.63%	1.31%
Weighted-Average Term Extension (in Months) \| mo			0	0
Average amount capitalized as a result of a payment delay \| $	$ 12,457	$ 11,166	$ 11,613	$ 10,487
Other
Loans in Mortgage Portfolio [Line Items]
Weighted-Average Interest Rate Reduction	1.76%	1.29%	1.31%	1.13%
Weighted-Average Term Extension (in Months) \| mo	148	135	143	158
Average amount capitalized as a result of a payment delay \| $	$ 16,556	$ 14,693	$ 15,304	$ 12,930