Investments (Past Due and Interest Accrual Status of Mortgage Loans) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	$ 80,464	$ 79,860
Greater than 90 Days Past Due and Still Accruing Interest	77	37
Financing Receivable, Nonaccrual	917	822
Financial Asset, Past Due
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	722	587
Commercial Mortgage Loans
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	51,117	50,553
Greater than 90 Days Past Due and Still Accruing Interest	3	13
Financing Receivable, Nonaccrual	155	155	$ 317
Commercial Mortgage Loans | Financial Asset, Past Due
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	3	13
Residential Mortgage Loans
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	11,465	11,196
Greater than 90 Days Past Due and Still Accruing Interest	13	8
Financing Receivable, Nonaccrual	537	442	534
Residential Mortgage Loans | Financial Asset, Past Due
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	550	450
Agricultural Mortgage Loans
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	17,882	18,111
Greater than 90 Days Past Due and Still Accruing Interest	61	16
Financing Receivable, Nonaccrual	225	225	$ 266
Agricultural Mortgage Loans | Financial Asset, Past Due
Financing Receivable, Nonaccrual [Line Items]
Mortgage Loans, Gross	$ 169	$ 124