Investments (Mortgage Loans by Maturity Date) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	$ 6,329	$ 5,861
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	100.00%	100.00%
Mortgage Loans On Real Estate Due One Year Through Five Years [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	$ 2,660	$ 2,276
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	42.00%	38.80%
Mortgage Loans On Real Estate Due After Five Years [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	$ 2,593	$ 2,768
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	41.00%	47.30%
Mortgage Loans On Real Estate Due After Ten Years [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	$ 1,076	$ 817
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	17.00%	13.90%