Investments (Past Due and Interest Accrual Status of Mortgage Loans) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	$ 79,860	$ 84,344
Greater than 90 Days Past Due and Still Accruing Interest	37	91
Nonaccrual	822	1,117
Financial Asset, Past Due
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	587	818
Commercial Mortgage Loans
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	50,553	52,434
Greater than 90 Days Past Due and Still Accruing Interest	13	7
Nonaccrual	155	317	$ 176
Commercial Mortgage Loans | Financial Asset, Past Due
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	13	10
Residential Mortgage Loans
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	11,196	13,782
Greater than 90 Days Past Due and Still Accruing Interest	8	64
Nonaccrual	442	534	418
Residential Mortgage Loans | Financial Asset, Past Due
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	450	556
Agricultural Mortgage Loans
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	18,111	18,128
Greater than 90 Days Past Due and Still Accruing Interest	16	20
Nonaccrual	225	266	$ 137
Agricultural Mortgage Loans | Financial Asset, Past Due
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	$ 124	$ 252