v3.24.4
Investments (Schedule of Fair Value of Securities in a Continuous Unrealized Loss Position for Less Than 12 Months and More Than 12 Months) (Details)
$ in Millions
Dec. 31, 2023
USD ($)
securities
Dec. 31, 2022
USD ($)
securities
US Treasury and Government    
Summary of Investment Holdings [Line Items]    
Available-for-sale investment securities, continuous unrealized loss position, number of securities | securities 105 123
Available-for-sale investment securities, continuous unrealized loss position, less than 12 months, fair value $ 3,513 $ 9,060
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss (13) (175)
Available-for-sale investment securities, continuous unrealized loss position, more than 12 months, fair value 3,978 106
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss $ (73) $ (3)
Residential Mortgage Backed Securities - Agency [Member]    
Summary of Investment Holdings [Line Items]    
Available-for-sale investment securities, continuous unrealized loss position, number of securities | securities 31 34
Available-for-sale investment securities, continuous unrealized loss position, less than 12 months, fair value $ 0 $ 559
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss 0 (22)
Available-for-sale investment securities, continuous unrealized loss position, more than 12 months, fair value 465 5
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss $ (15) $ (1)