Investments (Credit Quality of Agricultural and Residential Mortgage Loans) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
Mortgage Loans, Gross	$ 93,227	$ 84,290
Mortgage Loans in Process of Foreclosure, Amount	140	146
Residential Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	772
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,554
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,523
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	352
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	971
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	6,924
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 13,096	12,482
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	$ 767
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,508
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,501
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	336
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	927
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	6,639
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 12,678
Loans Receivable Residential Mortgage Percentage	96.80%
Residential Mortgage Loans | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 5
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	46
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	22
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	16
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	44
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	285
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 418
Loans Receivable Residential Mortgage Percentage	3.20%
Agricultural Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 1,157
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,892
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2,951
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,890
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,885
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	6,509
Financing Receivable, Revolving	1,521
Mortgage Loans, Gross	$ 19,805	$ 19,306
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	$ 1,123
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,796
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2,650
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,725
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,728
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	5,953
Financing Receivable, Revolving	1,394
Mortgage Loans, Gross	$ 18,369
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	$ 30
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	96
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	301
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	160
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	24
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	542
Financing Receivable, Revolving	121
Mortgage Loans, Gross	$ 1,274
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	$ 4
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	5
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	133
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	14
Financing Receivable, Revolving	6
Mortgage Loans, Gross	$ 162
Loans Receivable Agricultural Mortgage Percentage	0.80%