Share-Based Awards (Summary Of Stock Appreciation Right Transactions) (Details) - Stock Appreciation Rights (SARs) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
SARs granted (in shares)	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Options outstanding, beginning of period	75
Options exercised	(32)
Options forfeited	(16)
Options outstanding, beginning of period	27	75
Exercisable, end of period	27
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instrument Other Than Options Outstanding, Weighted Average Exercise Price [Roll Forward]
Weighted-Average Price, Options outstanding, beginning of period (in dollars per share)	$ 37
Weighted-Average Price, Options exercised (in dollars per share)	31
Weighted-Average Price, Options forfeited (in dollars per share)	62
Weighted-Average Price, Options outstanding, beginning of period (in dollars per share)	30	$ 37
Weighted-Average Price, Exercisable, end of period (in dollars per share)	$ 30
Weighted average fair value of SARs granted during period (in dollars per share)			$ 13