Share-Based Awards (Summary Of Stock Option Transactions) (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2017 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding, beginning of period | shares	1,878
Options exercised | shares	(282)
Options forfeited | shares	(192)
Options outstanding, end of period | shares	1,404
Exercisable, end of period | shares	1,309
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted-Average Price, Options outstanding, beginning of period (in dollars per share) | $ / shares	$ 49
Weighted-Average Price, Options exercised (in dollars per share) | $ / shares	40
Weighted-Average Price, Options forfeited (in dollars per share) | $ / shares	68
Weighted-Average Price, Options outstanding, end of period (in dollars per share) | $ / shares	48
Weighted-Average Price, Exercisable, end of period (in dollars per share) | $ / shares	$ 47