Net Income Per Common Share (Calculations For Basic And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Numerator:
Net Income (Loss)	$ 1,843	$ (487)	$ 2,968
Denominator:
Basic weighted-average common shares outstanding	157.0	158.8	161.0
Diluted weighted-average shares	158.1	158.8	162.7
Earnings (loss) per share:
Basic (in usd per share)	$ 11.74	$ (3.06)	$ 18.43
Diluted (in usd per share)	$ 11.66	$ (3.06)	$ 18.24
Number of anti-dilutive share-based awards	1.3	2.2	0.8
Stock Options
Denominator:
Effect of stock-based awards	0.7	0.0	1.1
Restricted Stock Units (RSUs)
Denominator:
Effect of stock-based awards	0.4	0.0	0.6