Mortgage Loans - Loan Restructuring - Financial Impacts (Details) - Single-family	3 Months Ended		9 Months Ended
	Sep. 30, 2025 USD ($) mo	Sep. 30, 2024 USD ($) mo	Sep. 30, 2025 USD ($) mo	Sep. 30, 2024 USD ($) mo
20- and 30-year or more, amortizing fixed-rate
Loans in Mortgage Portfolio [Line Items]
Weighted-Average Interest Rate Reduction	0.54%	0.59%	0.58%	0.72%
Weighted-Average Term Extension (in Months) | mo	142	160	148	161
Average amount capitalized as a result of a payment delay	$ 13,469	$ 12,928	$ 13,162	$ 13,408
15-year or less, amortizing fixed-rate
Loans in Mortgage Portfolio [Line Items]
Weighted-Average Interest Rate Reduction	0.87%	1.03%	1.02%	1.82%
Weighted-Average Term Extension (in Months) | mo	50	77	51	84
Average amount capitalized as a result of a payment delay	$ 10,061	$ 9,652	$ 9,642	$ 11,538
Adjustable-rate
Loans in Mortgage Portfolio [Line Items]
Weighted-Average Interest Rate Reduction	1.19%	2.88%	1.09%	2.58%
Average amount capitalized as a result of a payment delay	$ 9,970	$ 11,157	$ 10,115	$ 11,508
Other
Loans in Mortgage Portfolio [Line Items]
Weighted-Average Interest Rate Reduction	0.67%	0.96%	1.05%	0.86%
Weighted-Average Term Extension (in Months) | mo	131	182	150	162
Average amount capitalized as a result of a payment delay	$ 14,735	$ 21,043	$ 13,571	$ 18,705