Stock-Based Compensation (Schedule Of Option Activity And Changes) (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) $ / shares shares
Options
Options, Outstanding, beginning balance | shares	1,385,948
Options, Granted | shares	462,007
Options, Exercised | shares	(247,414)
Options, Cancelled | shares	(21,671)
Options, Outstanding, ending balance | shares	1,578,870
Options, Exercisable, ending balance | shares	877,908
Weighted Average Exercise Price
Weighted Average Exercise Price, Outstanding, beginning balance (in dollars per share) | $ / shares	$ 60.29
Weighted Average Exercise Price, Granted (in dollars per share) | $ / shares	65.81
Weighted Average Exercise Price, Exercised (in dollars per share) | $ / shares	23.78
Weighted Average Exercise Price, Cancelled (in dollars per share) | $ / shares	77.46
Weighted Average Exercise Price, Outstanding, ending balance (in dollars per share) | $ / shares	67.39
Weighted Average Exercise Price, Exercisable, ending balance (in dollars per share) | $ / shares	$ 62.91
Weighted Average Remaining Term (Years) [Abstract]
Weighted Average Remaining Term (Years), Outstanding	6 years 9 months 18 days
Weighted Average Remaining Term (Years), Exercisable	5 years 2 months 12 days
Aggregate Intrinsic Value [Abstract]
Aggregate Intrinsic Value, Outstanding | $	$ 27
Aggregate Intrinsic Value, Exercisable | $	$ 19