Earnings Per Share (Summary Of Calculation Of Basic And Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Share data	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Earnings Per Share
Income from continuing operations	$ 16,525	$ 15,963	$ 55,857	$ 46,256
Discontinued operations	2,283	1,371	7,161	6,210
Net income available to common stockholders	$ 18,808	$ 17,334	$ 63,018	$ 52,466
Weighted average common shares outstanding, basic	27,729,560	27,673,703	27,711,474	27,657,236
Income from continuing operations per common share, basic	$ 0.60	$ 0.57	$ 2.02	$ 1.67
Discontinued operations per common share, basic	$ 0.08	$ 0.05	$ 0.26	$ 0.22
Net income per common share	$ 0.68	$ 0.62	$ 2.28	$ 1.89
Weighted average common shares outstanding, diluted	27,729,560	27,673,703	27,711,474	27,657,236
Stock options, diluted	59,010	61,403	82,130	55,921
Restricted shares, diluted	1,155	2,696	1,546	2,948
Average dilutive common shares outstanding	27,789,725	27,737,802	27,795,150	27,716,105
Income from continuing operations per common share	$ 0.60	$ 0.57	$ 2.01	$ 1.67
Discontinued operations per common share	$ 0.08	$ 0.05	$ 0.26	$ 0.22
Net income per common share	$ 0.68	$ 0.62	$ 2.27	$ 1.89
Incremental shares excluded since anti-dilutive: Stock options	37,048	2,347	14,962	2,249

Amount Of Dilutive Securities Restrictive Stock Units

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Amount Of Dilutive Securities Stock Options

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) in the future that were not included in the computation of diluted EPS because to do so would increase EPS amounts or decrease loss per share amounts for the period presented.

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

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The amount of net income or loss for the period per each share of common stock and dilutive common stock equivalents outstanding during the reporting period.

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This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses and taxes from ongoing operations before extraordinary items, cumulative effects of changes in accounting principles, and noncontrolling interest.

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The amount of income (loss) from continuing operations per each share of common stock outstanding during the reporting period.

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

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This element represents the overall income (loss) from a disposal group that is classified as a component of the entity, net of income tax, reported as a separate component of income before extraordinary items and the cumulative effect of accounting changes before deduction or consideration of the amount which may be allocable to noncontrolling interests, if any. Includes the following (net of tax): income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.

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The amount of income (loss) from disposition of discontinued operations, net of related tax effect, per each share of common stock outstanding during the reporting period.

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The amount of income (loss) from discontinued operations, net of related tax effect, per each diluted share of common stock outstanding during the reporting period.

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The portion of consolidated profit or loss for the period, net of income taxes, which is attributable to the parent. If the entity does not present consolidated financial statements, the amount of profit or loss for the period, net of income taxes.

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The sum of dilutive potential common shares used in the calculation of the diluted per-share computation.

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The average number of shares issued and outstanding that are used in calculating diluted EPS, determined based on the timing of issuance of shares in the period.

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

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