Investments (Past Due and Interest Accrual Status of Mortgage Loans) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	$ 92,272	$ 93,227
Greater than 90 Days Past Due and Still Accruing Interest	80	19
Financing Receivable, Nonaccrual	1,351	1,035
Financial Asset, Past Due
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	1,110	533
Commercial Mortgage Loans
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	59,359	60,326
Greater than 90 Days Past Due and Still Accruing Interest	36	3
Financing Receivable, Nonaccrual	665	427
Commercial Mortgage Loans | Financial Asset, Past Due
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	424	75
Residential Mortgage Loans
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	13,201	13,096
Greater than 90 Days Past Due and Still Accruing Interest	15	16
Financing Receivable, Nonaccrual	428	402
Residential Mortgage Loans | Financial Asset, Past Due
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	440	418
Agricultural Mortgage Loans
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	19,712	19,805
Greater than 90 Days Past Due and Still Accruing Interest	29	0
Financing Receivable, Nonaccrual	258	206
Agricultural Mortgage Loans | Financial Asset, Past Due
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	$ 246	$ 40