Stock Transactions And Stock-Based Compensation (Summary Of Options Outstanding) (Details) shares in Millions	12 Months Ended
	Dec. 31, 2018 $ / shares shares
$19.89 to $39.60
Options, exercise price, lower range limit	$ 19.89
Options, exercise price, upper range limit	$ 39.60
Outstanding, shares (in millions) | shares	2.1
Outstanding, average exercise price	$ 34.15
Outstanding, average remaining life (in years)	2 years
Exercisable, shares (in millions) | shares	2.0
Exercisable, average exercise price	$ 34.13
$39.61 to $56.70
Options, exercise price, lower range limit	39.61
Options, exercise price, upper range limit	$ 56.70
Outstanding, shares (in millions) | shares	2.5
Outstanding, average exercise price	$ 48.73
Outstanding, average remaining life (in years)	4 years
Exercisable, shares (in millions) | shares	2.3
Exercisable, average exercise price	$ 48.15
$56.71 to $70.75
Options, exercise price, lower range limit	56.71
Options, exercise price, upper range limit	$ 70.75
Outstanding, shares (in millions) | shares	6.1
Outstanding, average exercise price	$ 64.58
Outstanding, average remaining life (in years)	6 years
Exercisable, shares (in millions) | shares	2.6
Exercisable, average exercise price	$ 63.64
$70.76 to $86.08
Options, exercise price, lower range limit	70.76
Options, exercise price, upper range limit	$ 86.08
Outstanding, shares (in millions) | shares	3.9
Outstanding, average exercise price	$ 85.13
Outstanding, average remaining life (in years)	8 years
Exercisable, shares (in millions) | shares	0.7
Exercisable, average exercise price	$ 84.37
$86.09 to $101.65
Options, exercise price, lower range limit	86.09
Options, exercise price, upper range limit	$ 101.65
Outstanding, shares (in millions) | shares	4.0
Outstanding, average exercise price	$ 99.23
Outstanding, average remaining life (in years)	9 years
Exercisable, shares (in millions) | shares	0.1
Exercisable, average exercise price	$ 95.44