Mortgage Loans - Credit Quality Indicators - MF (Details) - Multifamily - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	$ 59,402	$ 59,007
One fiscal year before	65,786	80,197
Two fiscal years before	76,984	66,566
Three fiscal years before	62,378	57,666
Four fiscal years before	51,270	48,128
Prior	116,402	94,641
Total loans held for investment	432,222	406,205
Non-classified
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	57,987	58,986
One fiscal year before	64,206	79,602
Two fiscal years before	75,596	64,278
Three fiscal years before	59,562	55,552
Four fiscal years before	48,774	44,037
Prior	104,078	87,549
Total loans held for investment	410,203	390,004
Classified
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	1,415	21
One fiscal year before	1,580	595
Two fiscal years before	1,388	2,288
Three fiscal years before	2,816	2,114
Four fiscal years before	2,496	4,091
Prior	12,324	7,092
Total loans held for investment	22,019	16,201
Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held for investment	9,200	5,600
Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held for investment	$ 8	$ 1