Investments (Mortgage Loans by Maturity Date) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 6,583	$ 6,329
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	100.00%	100.00%
Due within five years
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 2,724	$ 2,660
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	41.40%	42.00%
Due after five years through ten years
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 2,738	$ 2,593
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	41.60%	41.00%
Due after ten years
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 1,121	$ 1,076
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	17.00%	17.00%