Investments (Schedule Of Available-For-Sale Securities Whose Value Is Below Amortized Cost) (Details) $ in Millions	Sep. 30, 2022 USD ($) security	Dec. 31, 2021 USD ($) security
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 77,639	$ 16,786
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer	5,744	1,973
Debt Securities, Available-for-sale, Unrealized Loss Position, Total	83,383	18,759
Less Than or Equal to Twelve Months	12,693	313
Greater Than Twelve Months	1,687	138
Fair Value - Total	$ 14,380	$ 451
Number of Securities - Total | security	8,129	2,597
Fair Value Decline, Greater Than 20% [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value - Less than six months	$ 19,010	$ 12
Fair Value - Six months or greater, but less than nine months	477
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer	1	58
Debt Securities, Available-for-sale, Unrealized Loss Position, Total	19,489	70
Gross Unrealized Losses - Less than six months	7,186	3
Gross Unrealized Losses - Six months or greater, but less than nine months	326
Greater Than Twelve Months		8
Fair Value - Total	$ 7,512	$ 11
Number of Securities - Less than six months | security	2,166	6
Number of Securities - Six months or greater, but less than nine months | security	79
Number of Securities - Twelve months or greater | security	13	24
Number of Securities - Total | security	2,260	30