Stock Transactions And Stock-Based Compensation (Components Of Share-Based Compensation Program) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pretax compensation expense	$ 187	$ 159	$ 138
Income tax benefit	(39)	(33)	(28)
Total stock-based compensation expense, net of income taxes	148	126	110
RSUs/PSUs
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pretax compensation expense	114	97	86
Income tax benefit	(24)	(20)	(17)
Total stock-based compensation expense, net of income taxes	90	77	69
Stock options
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pretax compensation expense	73	62	52
Income tax benefit	(15)	(13)	(11)
Total stock-based compensation expense, net of income taxes	$ 58	$ 49	$ 41