Investments (Mortgage Loans by Portfolio Segment) (Details) - Mortgage Loans - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit losses	$ 23,070	$ 22,612
Financing receivable, allowance for credit losses	(167)	(137)	$ (137)	$ (119)
Financing receivable, net of allowance for credit losses	$ 22,903	$ 22,475
Financing receivable, before allowance for credit losses as a percentage of financing receivable, net of allowance for credit losses	100.70%	100.60%
Financing receivable, allowance for credit losses as a percentage of financing receivable, net of allowance for credit losses	(0.70%)	(0.60%)
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	$ 13,251	$ 13,189
Financing receivable, allowance for credit losses	$ (95)	$ (69)	(67)	(49)
Financing receivable, before allowance for credit losses as a percentage of financing receivable, net of allowance for credit losses	57.90%	58.70%
Agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit losses	$ 4,490	$ 4,416
Financing receivable, allowance for credit losses	$ (30)	$ (19)	(15)	(15)
Financing receivable, before allowance for credit losses as a percentage of financing receivable, net of allowance for credit losses	19.60%	19.60%
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit losses	$ 5,329	$ 5,007
Financing receivable, allowance for credit losses	$ (42)	$ (49)	$ (55)	$ (55)
Financing receivable, before allowance for credit losses as a percentage of financing receivable, net of allowance for credit losses	23.20%	22.30%