Investments (Schedule Of Available-For-Sale Securities Whose Value Is Below Amortized Cost) (Details) $ in Millions	Jun. 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	$ 70,723	$ 16,786
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer	4,711	1,973
Debt Securities, Available-for-sale, Unrealized Loss Position, Total	75,434	18,759
Less Than or Equal to Twelve Months	7,452	313
Greater Than Twelve Months	1,100	138
Fair Value - Total	$ 8,552	$ 451
Number of Securities - Total | security	7,122	2,597
Fair Value Decline, Greater Than 20% [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value - Less than six months	$ 8,166	$ 12
Fair Value - Six months or greater, but less than nine months	4
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer	1	58
Debt Securities, Available-for-sale, Unrealized Loss Position, Total	8,171	70
Gross Unrealized Losses - Less than six months	2,797	3
Gross Unrealized Losses - Six months or greater, but less than nine months	1
Greater Than Twelve Months	1	8
Fair Value - Total	$ 2,799	$ 11
Number of Securities - Less than six months | security	1,040	6
Number of Securities - Six months or greater, but less than nine months | security	3
Number of Securities - Twelve months or greater | security	17	24
Number of Securities - Total | security	1,060	30