Investments (Analysis of Past Due Commercial Mortgage and Other Loans) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Past Due [Line Items]
Total Loans	$ 58,785	$ 65,660
Non-Accrual Status	22	21
Held-for-sale
Financing Receivable, Past Due [Line Items]
Total Loans	6,580
Current
Financing Receivable, Past Due [Line Items]
Total Loans	58,782	65,484
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	41
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	119
90 days or more past due
Financing Receivable, Past Due [Line Items]
Total Loans	3	16
Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	3	176
Commercial Mortgage Loans
Financing Receivable, Past Due [Line Items]
Total Loans	52,567	60,736
Non-Accrual Status	2	5
Commercial Mortgage Loans | Current
Financing Receivable, Past Due [Line Items]
Total Loans	52,565	60,614
Commercial Mortgage Loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	3
Commercial Mortgage Loans | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	119
Commercial Mortgage Loans | 90 days or more past due
Financing Receivable, Past Due [Line Items]
Total Loans	2	0
Commercial Mortgage Loans | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	2	122
Agricultural property loans
Financing Receivable, Past Due [Line Items]
Total Loans	5,520	4,048
Non-Accrual Status	19	15
Agricultural property loans | Current
Financing Receivable, Past Due [Line Items]
Total Loans	5,520	3,996
Agricultural property loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	37
Agricultural property loans | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Agricultural property loans | 90 days or more past due
Financing Receivable, Past Due [Line Items]
Total Loans	0	15
Agricultural property loans | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	52
Residential property loans
Financing Receivable, Past Due [Line Items]
Total Loans	67	101
Non-Accrual Status	1	1
Residential property loans | Current
Financing Receivable, Past Due [Line Items]
Total Loans	66	99
Residential property loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	1
Residential property loans | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Residential property loans | 90 days or more past due
Financing Receivable, Past Due [Line Items]
Total Loans	1	1
Residential property loans | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	1	2
Other Collateralized Loans
Financing Receivable, Past Due [Line Items]
Total Loans	70	120
Non-Accrual Status	0	0
Other Collateralized Loans | Current
Financing Receivable, Past Due [Line Items]
Total Loans	70	120
Other Collateralized Loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Other Collateralized Loans | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Other Collateralized Loans | 90 days or more past due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Other Collateralized Loans | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Uncollateralized loans
Financing Receivable, Past Due [Line Items]
Total Loans	561	655
Non-Accrual Status	0	0
Uncollateralized loans | Current
Financing Receivable, Past Due [Line Items]
Total Loans	561	655
Uncollateralized loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Uncollateralized loans | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Uncollateralized loans | 90 days or more past due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Uncollateralized loans | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Loans | 90 days or more past due
Financing Receivable, Past Due [Line Items]
Accruing Interest	$ 0	$ 0