Mortgage Loans - Loan Restructuring - Financial Impacts (Details) - Single-family	3 Months Ended
	Mar. 31, 2022 USD ($) mo
20- and 30-year or more, amortizing fixed-rate
Loans in Mortgage Portfolio [Line Items]
Weighted-Average Interest Rate Reduction	1.59%
Weighted-Average Term Extension (in Months) | mo	178
Average Amount Capitalized as a Result of a Payment Delay	$ 23,146
15-year or less, amortizing fixed-rate
Loans in Mortgage Portfolio [Line Items]
Weighted-Average Interest Rate Reduction	0.88%
Weighted-Average Term Extension (in Months) | mo	52
Average Amount Capitalized as a Result of a Payment Delay	$ 20,664
Adjustable-rate
Loans in Mortgage Portfolio [Line Items]
Weighted-Average Interest Rate Reduction	0.22%
Average Amount Capitalized as a Result of a Payment Delay	$ 24,838
Other
Loans in Mortgage Portfolio [Line Items]
Weighted-Average Interest Rate Reduction	1.62%
Weighted-Average Term Extension (in Months) | mo	186
Average Amount Capitalized as a Result of a Payment Delay	$ 24,759