Earnings Per Share (Components Of Earnings Per Common Share - Basic And Diluted) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Earnings Per Share [Abstract]
Income from continuing operations	$ 16,373	$ 11,113
Gain on sale of property	440	1,060
Net income attributable to noncontrolling interests	(1,441)	(1,092)
Preferred share dividends	(8,869)	(8,869)
Income from continuing operations attributable to common shareholders - basic and diluted	6,503	2,212
Income from discontinued operations attributable to common shareholders - basic and diluted	$ 5,825	$ 5,015
Weighted average shares outstanding - basic	120,481	120,142
Share options and awards	960	959
Weighted average shares outstanding - diluted	121,441	121,101

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This element represents the amount of gain (loss) on sale of properties during the reporting period gross of the applicable income taxes realized.

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This element represents the income or loss from continuing operations attributable to the parent which may also be defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests, if any.

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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, and noncontrolling interest.

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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 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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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 net Income or Loss attributable to the noncontrolling interest (if any) deducted in order to derive the portion attributable to the parent.

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The amount of preferred stock dividends that is an adjustment to net income apportioned to common stockholders.

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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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