Stockholders' Equity (Summary Of Dividends Paid On Common Stock) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022
Stockholders Equity [Line Items]
Dividends amount	$ 0	$ 462	$ 596	$ 1,007	$ 830	$ 667
Dividends rate per share	$ 0	$ 0.72	$ 0.89	$ 1.55	$ 1.27	$ 1
Total year to date	$ 1,370			$ 2,504
Fixed Dividend [Member]
Stockholders Equity [Line Items]
Dividends amount	0	$ 128	$ 133	117	$ 105	$ 109
Dividends rate per share			$ 0.2			$ 0.16
Total year to date	388			331
Variable Dividend [Member]
Stockholders Equity [Line Items]
Dividends amount	0	$ 334	$ 463	890	$ 725	$ 558
Total year to date	$ 982			$ 2,173