Investments (Mortgage Loans by Portfolio Segment) (Details) - Mortgage Loans - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit losses	$ 22,612	$ 22,996
Financing receivable, allowance for credit losses	(137)	(119)	$ (123)
Financing receivable, net of allowance for credit losses	$ 22,475	$ 22,877
Financing receivable, before allowance for credit losses as a percentage of financing receivable, net of allowance for credit losses	100.60%	100.50%
Financing receivable, allowance for credit losses as a percentage of financing receivable, net of allowance for credit losses	(0.60%)	(0.50%)
Financing receivable, after allowance for credit losses as a percentage of financing receivable, net of allowance for credit losses	100.00%	100.00%
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit losses	$ 13,189	$ 13,547
Financing receivable, allowance for credit losses	$ (69)	$ (49)	(67)
Financing receivable, before allowance for credit losses as a percentage of financing receivable, net of allowance for credit losses	58.70%	59.20%
Agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit losses	$ 4,416	$ 4,333
Financing receivable, allowance for credit losses	$ (19)	$ (15)	(12)
Financing receivable, before allowance for credit losses as a percentage of financing receivable, net of allowance for credit losses	19.60%	18.90%
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit losses	$ 5,007	$ 5,116
Financing receivable, allowance for credit losses	$ (49)	$ (55)	$ (44)
Financing receivable, before allowance for credit losses as a percentage of financing receivable, net of allowance for credit losses	22.30%	22.40%