Mortgage Loans - Credit Quality Indicators - MF (Details) - Multifamily - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	$ 23,068	$ 59,402
One fiscal year before	61,162	65,786
Two fiscal years before	64,871	76,984
Three fiscal years before	76,312	62,378
Four fiscal years before	61,736	51,270
Prior	159,001	116,402
Total mortgage loans	446,150	432,222
Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	23,068	57,976
One fiscal year before	55,124	64,165
Two fiscal years before	61,194	75,468
Three fiscal years before	74,157	59,507
Four fiscal years before	58,280	48,720
Prior	143,885	103,772
Total mortgage loans	415,708	409,608
Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	11
One fiscal year before	8	41
Two fiscal years before	91	128
Three fiscal years before	64	55
Four fiscal years before	16	54
Prior	331	306
Total mortgage loans	510	595
Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	1,415
One fiscal year before	6,030	1,580
Two fiscal years before	3,586	1,388
Three fiscal years before	2,091	2,816
Four fiscal years before	3,435	2,488
Prior	14,784	12,324
Total mortgage loans	29,926	22,011
Substandard | Senior Housing
Financing Receivable, Credit Quality Indicator [Line Items]
Total mortgage loans	9,200	9,200
Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
One fiscal year before	0	0
Two fiscal years before	0	0
Three fiscal years before	0	0
Four fiscal years before	5	8
Prior	1	0
Total mortgage loans	6	$ 8
Current-year write-offs
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0
One fiscal year before	3
Two fiscal years before	0
Three fiscal years before	5
Four fiscal years before	5
Prior	241
Total mortgage loans	$ 254