Investments (Credit Quality of Agricultural and Residential Mortgage Loans) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Mortgage Loans, Gross	$ 92,272	$ 93,227
Mortgage Loans in Process of Foreclosure, Amount	143	140
Residential Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	55
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	974
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2,575
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,597
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	337
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	7,663
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 13,201	13,096
Loans Receivable Residential Mortgage Percentage	100.00%
Residential Mortgage Loans | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 55
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	958
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2,507
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,575
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	323
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	7,343
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 12,761
Loans Receivable Residential Mortgage Percentage	96.70%
Residential Mortgage Loans | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	16
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	68
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	22
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	14
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	320
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 440
Loans Receivable Residential Mortgage Percentage	3.30%
Agricultural Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 158
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,198
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2,884
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,934
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,847
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	8,204
Financing Receivable, Revolving	1,487
Mortgage Loans, Gross	$ 19,712	$ 19,805
Loans Receivable Agricultural Mortgage Percentage	100.00%
Agricultural Mortgage Loans | Less than 65%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 152
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,163
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2,793
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,641
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,696
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	7,506
Financing Receivable, Revolving	1,351
Mortgage Loans, Gross	$ 18,302
Loans Receivable Agricultural Mortgage Percentage	92.80%
Agricultural Mortgage Loans | 65% to 75%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 6
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	30
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	91
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	293
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	147
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	556
Financing Receivable, Revolving	130
Mortgage Loans, Gross	$ 1,253
Loans Receivable Agricultural Mortgage Percentage	6.40%
Agricultural Mortgage Loans | 76% to 80%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 0
Loans Receivable Agricultural Mortgage Percentage	0.00%
Agricultural Mortgage Loans | Greater than 80%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	5
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	4
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	142
Financing Receivable, Revolving	6
Mortgage Loans, Gross	$ 157
Loans Receivable Agricultural Mortgage Percentage	0.80%