Earnings/(Loss) Per Share (Schedule Of Computation Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings/(Loss) Per Share[Abstract]
Loss, Income/(Loss)	$ (21,656)	$ 24,885	$ 8,188	$ 49,725
Diluted loss, Income/(Loss)	$ (21,656)	$ 24,885	$ 8,188	$ 49,725
Earnings, Shares	16,010	16,443	16,114	16,583
Dilutive stock options, Shares		289	557	297
Nonvested stock awards, Shares		99	87	119
Diluted Loss, Shares	16,010	16,831	16,758	16,999
Net income/(Loss) per Share	$ (1.35)	$ 1.51	$ 0.51	$ 3.00
Earnings/(Loss) per Share, Diluted earnings/(loss)	$ (1.35)	$ 1.48	$ 0.49	$ 2.93

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Number of additional shares included in diluted EPS for potentially dilutive effect of nonvested equity-based payment award containing forfeitable rights to dividends or dividend equivalents, whether paid or unpaid.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities, and addition from assumption of issuance of common shares for dilutive potential common shares; of income (loss) available to common shareholders.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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