Mortgage Loans - Loan Restructuring - Financial Impacts (Details) - Single-family	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) mo	Sep. 30, 2022 USD ($) mo	Sep. 30, 2023 USD ($) mo	Sep. 30, 2022 USD ($) mo
20- and 30-year or more, amortizing fixed-rate
Loans in Mortgage Portfolio [Line Items]
Weighted-Average Interest Rate Reduction	1.05%	1.18%	1.08%	1.45%
Weighted-Average Term Extension (in Months) | mo	167	179	171	179
Average amount capitalized as a result of a payment delay	$ 16,464	$ 20,896	$ 16,798	$ 22,862
15-year or less, amortizing fixed-rate
Loans in Mortgage Portfolio [Line Items]
Weighted-Average Interest Rate Reduction	2.41%	1.88%	2.22%	2.31%
Weighted-Average Term Extension (in Months) | mo	52	45	70	52
Average amount capitalized as a result of a payment delay	$ 14,218	$ 16,950	$ 14,588	$ 19,872
Adjustable-rate
Loans in Mortgage Portfolio [Line Items]
Weighted-Average Interest Rate Reduction	1.97%	1.47%	1.29%	0.82%
Average amount capitalized as a result of a payment delay	$ 12,980	$ 22,079	$ 14,823	$ 23,065
Other
Loans in Mortgage Portfolio [Line Items]
Weighted-Average Interest Rate Reduction	1.04%	1.66%	1.31%	1.82%
Weighted-Average Term Extension (in Months) | mo	199	192	188	184
Average amount capitalized as a result of a payment delay	$ 23,072	$ 21,042	$ 21,396	$ 23,776