Stock-based Compensation (Schedule Of Stock Option Exercises) (Details) - Stock Options [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock Option Aggregate Disclosures [Abstract]
Intrinsic value of stock options exercised	$ 193	$ 83	$ 88
Cash received from option exercises	130	76	59
Treasury shares repurchased for employee payroll taxes	(37)	(20)	(18)
Tax benefit realized from option exercises	48	21	34
Aggregate grant-date fair value of stock options vested	$ 15	$ 19	$ 20