Stock-Based Compensation (Schedule Of Stock Option Plans Activity) (Details) - $ / shares	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Shares
Options outstanding at beginning of year (in shares)	298,000
Options granted (in shares)	0
Options exercised (in shares)	(66,000)
Options forfeited and expired (in shares)	(63,000)
Options outstanding at end of year (in shares)	169,000	298,000
Options exercisable at end of year (in shares)	164,000
Weighted average exercise price
Options granted during the year (USD per share)	$ 0.00
Options exercised during the year (USD per share)	73.33
Options outstanding at the end of year (USD per share)	61.73	$ 68.63
Options exercisable at end of year (USD per share)	$ 61.73
Stock Options Plans [Member]
Shares
Options outstanding at beginning of year (in shares)	298,000	425,000	995,000
Options granted (in shares)	0	0	0
Options exercised (in shares)	(66,000)	(108,000)	(561,000)
Options forfeited and expired (in shares)	(63,000)	(19,000)	(9,000)
Options outstanding at end of year (in shares)	169,000	298,000	425,000
Options exercisable at end of year (in shares)	164,000	257,000	343,000
Weighted average exercise price
Options granted during the year (USD per share)	$ 0.00	$ 0.00	$ 0.00
Minimum [Member]
Weighted average exercise price
Options exercised during the year (USD per share)	28.37	28.37	28.37
Options forfeited and expired during the year (USD per share)	28.37	46.80	48.50
Options outstanding at the end of year (USD per share)	28.37	28.37	28.37
Options exercisable at end of year (USD per share)	28.37	28.37	28.37
Maximum [Member]
Weighted average exercise price
Options exercised during the year (USD per share)	93.65	93.65	93.65
Options forfeited and expired during the year (USD per share)	88.33	93.65	88.33
Options outstanding at the end of year (USD per share)	93.65	93.65	93.65
Options exercisable at end of year (USD per share)	$ 93.65	$ 93.65	$ 93.65

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

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Net number of share options (or share units) granted during the period.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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