Investments (Past Due and Interest Accrual Status of Mortgage Loans) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	$ 93,227	$ 84,290
Greater than 90 Days Past Due and Still Accruing Interest	19	39
Financing Receivable, Nonaccrual	1,035	762
Financial Asset, Past Due
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	533	603
Commercial Mortgage Loans
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	60,326	52,502
Greater than 90 Days Past Due and Still Accruing Interest	3	6
Financing Receivable, Nonaccrual	427	169
Commercial Mortgage Loans | Financial Asset, Past Due
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	75	6
Residential Mortgage Loans
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	13,096	12,482
Greater than 90 Days Past Due and Still Accruing Interest	16	12
Financing Receivable, Nonaccrual	402	462
Residential Mortgage Loans | Financial Asset, Past Due
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	418	473
Agricultural Mortgage Loans
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	19,805	19,306
Greater than 90 Days Past Due and Still Accruing Interest	0	21
Financing Receivable, Nonaccrual	206	131
Agricultural Mortgage Loans | Financial Asset, Past Due
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	$ 40	$ 124