Investments (Past Due Mortgage Loans by Portfolio Segment) (Details) - Mortgage Loans - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	$ 23,070	$ 22,612
Current
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	22,740	22,487
30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	95	2
60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	49	30
90 to 179 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	46	23
180 Days and Greater Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	140	70
Commercial
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	13,251	13,189
Commercial | Current
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	13,142	13,172
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	10	0
Commercial | 90 to 179 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	14	0
Commercial | 180 Days and Greater Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	85	17
Agricultural
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	4,490	4,416
Agricultural | Current
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	4,465	4,400
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	9	0
Agricultural | 90 to 179 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	0	0
Agricultural | 180 Days and Greater Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	16	16
Residential
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	5,329	5,007
Residential | Current
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	5,133	4,915
Residential | 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	95	2
Residential | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	30	30
Residential | 90 to 179 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	32	23
Residential | 180 Days and Greater Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, before allowance for credit losses	$ 39	$ 37