Investments (Financing Receivables Past Due) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 6,583	$ 6,329
Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	6,564	6,329
Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	0
Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 19	$ 0