Stockholders' Equity (Summary Of Dividends Paid On Common Stock) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Stockholders Equity [Line Items]
Dividends amount	$ 462	$ 596	$ 830	$ 667
Dividends rate per share		$ 0.89		$ 1	$ 0.72	$ 1.27
Total year to date	1,058		1,497		$ 1,058	$ 1,497
Fixed Dividend [Member]
Stockholders Equity [Line Items]
Dividends amount	128	$ 133	105	$ 109
Dividends rate per share		$ 0.2		$ 0.16
Total year to date	261		214		261	214
Variable Dividend [Member]
Stockholders Equity [Line Items]
Dividends amount	334	$ 463	725	$ 558
Total year to date	$ 797		$ 1,283		$ 797	$ 1,283