Investment Securities (Schedule Of Realized Gain (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Gross realized gains	$ 5	$ 23	$ 102
Net realized gain on available-for-sale securities	5	23	102
Net realized gain on equity securities	32	72	190
Net unrealized gain (loss) on equity securities	107	(215)	(7)
Other gain (loss) on investments, net	$ 144	$ (120)	$ 285