Investments (Past Due Mortgage Loans by Portfolio Segment) (Details) - Mortgage Loans - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	$ 22,996	$ 19,910
Current
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	22,902	19,837
30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	11	14
60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	16	14
90 to 179 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	34	29
180 Days and Greater Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	33	16
Commercial
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	13,547	12,159
Commercial | Current
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	13,547	12,159
Commercial | 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	0	0
Commercial | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	0	0
Commercial | 90 to 179 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	0	0
Commercial | 180 Days and Greater Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	0	0
Agricultural
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	4,333	4,128
Agricultural | Current
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	4,314	4,128
Agricultural | 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	0	0
Agricultural | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	0	0
Agricultural | 90 to 179 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	3	0
Agricultural | 180 Days and Greater Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	16	0
Residential
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	5,116	3,623
Residential | Current
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	5,041	3,550
Residential | 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	11	14
Residential | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	16	14
Residential | 90 to 179 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	31	29
Residential | 180 Days and Greater Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	$ 17	$ 16