Share-Based Awards (Summary Of Stock Appreciation Right Transactions) (Details) - Stock Appreciation Rights (SARs) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
SARs granted (in shares)	0
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Options outstanding, beginning of period	162,000
Options exercised	(84,000)
Options forfeited	(3,000)
Options outstanding, beginning of period	75,000	162,000
Exercisable, end of period	65,000
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)	$ 33
Weighted-Average Price, Options exercised (in dollars per share)	29
Weighted-Average Price, Options forfeited (in dollars per share)	63
Weighted-Average Price, Options outstanding, beginning of period (in dollars per share)	37	$ 33
Weighted-Average Price, Exercisable, end of period (in dollars per share)	$ 34
Weighted average fair value of SARs granted during period (in dollars per share)		$ 13	$ 14