Earnings Per Share (EPS) And Dividends (Basic And Diluted Earnings Per Share Computation) (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	1 Months Ended	2 Months Ended	3 Months Ended
	Mar. 31, 2022	Feb. 28, 2022	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Stock Repurchase Program, Authorized Amount					$ 500
Accelerated Share Repurchases, Settlement (Payment) or Receipt	$ 250		$ 250
Accelerated Share Repurchase percentage of initial shares received	80.00%
Payments for Repurchase of Common Stock		$ 250	$ 500	$ 0
Accelerated Share Repurchases, Initial Price Paid Per Share	$ 65.72
Treasury Stock, Shares, Acquired	3,000
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount			3,000
Net Income			$ (2)	$ 648
Weighted Average Common Shares Outstanding, Basic (shares)			501,000	504,000
Effect of Stock Based Compensation Awards, Basic (shares)			0	0
Total Shares, Basic (shares)			501,000	504,000
Net Income, Basic (dollars per share)			$ 0.00	$ 1.29
Weighted Average Common Shares Outstanding, Diluted (shares)			501,000	504,000
Effect of Stock Based Compensation Awards, Diluted (shares)			0	3,000
Total Shares, Diluted (shares)			501,000	507,000
Net Income, Diluted (dollars per share)			$ 0.00	$ 1.28