Stock-Based Compensation (Schedule Of Option Activity And Changes) (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares shares
Options
Options, Outstanding, beginning balance | shares	1,115,954
Options, Granted | shares	296,598
Options, Exercised | shares	(18,635)
Options, Cancelled | shares	(7,969)
Options, Outstanding, ending balance | shares	1,385,948
Options, Exercisable, ending balance | shares	888,093
Weighted Average Exercise Price
Weighted Average Exercise Price, Outstanding, beginning balance (in dollars per share) | $ / shares	$ 54.82
Weighted Average Exercise Price, Granted (in dollars per share) | $ / shares	79.83
Weighted Average Exercise Price, Exercised (in dollars per share) | $ / shares	35.04
Weighted Average Exercise Price, Cancelled (in dollars per share) | $ / shares	79.94
Weighted Average Exercise Price, Outstanding, ending balance (in dollars per share) | $ / shares	60.29
Weighted Average Exercise Price, Exercisable, ending balance (in dollars per share) | $ / shares	$ 47.64
Weighted Average Remaining Term (Years) [Abstract]
Weighted Average Remaining Term (Years), Outstanding	5 years 10 months 24 days
Weighted Average Remaining Term (Years), Exercisable	4 years 6 months
Aggregate Intrinsic Value [Abstract]
Aggregate Intrinsic Value, Outstanding | $	$ 23
Aggregate Intrinsic Value, Exercisable | $	$ 22