Per Share Data (Calculation Of Basic And Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Earnings Per Share [Abstract]
Number of common share equivalent securities excluded from the diluted earnings per share calculation	3,300,000	3,700,000	2,400,000	4,800,000
Income (loss) from continuing operations attributable to common shareholders	$ 30,360	$ 10,751	$ 108,091	$ (638)
Amount allocated to participating securities	(288)	(154)	(1,387)	(118)
Income (loss) from continuing operations attributable to common shareholders, net of amount allocated to participating securities	30,072	10,597	106,704	(756)
Income from discontinued operations, including gain on sale, attributable to common shareholders	343	1,089	33,133	3,167
Net income attributable to common shareholders, as adjusted	30,415	11,686	139,837	2,411
Income (loss) from continuing operations attributable to common shareholders, as adjusted - per share	$ 0.35	$ 0.14	$ 1.29	$ (0.01)
Income from discontinued operations, including gain on sale, attributable to common shareholders	$ 0.01	$ 0.02	$ 0.40	$ 0.04
Net income attributable to common shareholders, as adjusted - per share	$ 0.36	$ 0.16	$ 1.69	$ 0.03
Weighted average number of common shares outstanding - basic	85,631,000	73,242,000	82,923,000	72,502,000
Income allocated to common units from continuing operations	0	8	1,167	0
Income (loss) from continuing operations attributable to common shareholders, as adjusted	30,072	10,605	107,871	(756)
Net income attributable to common shareholders, as adjusted	$ 30,415	$ 11,694	$ 141,004	$ 2,411
Income (loss) from continuing operations attributable to common shareholders, as adjusted - per share	$ 0.35	$ 0.14	$ 1.27	$ (0.01)
Income from discontinued operations, including gain on sale, attributable to common shareholders - per share	$ 0.00	$ 0.02	$ 0.39	$ 0.04
Net income attributable to common shareholders, as adjusted - per share	$ 0.35	$ 0.16	$ 1.66	$ 0.03
Common share options and share awards granted	662,000	793,000	655,000	0
Common units	0	239,000	1,116,000	0
Weighted average number of common shares outstanding - diluted	86,293,000	74,274,000	84,694,000	72,502,000

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 and incremental common shares attributable to participating nonvested shares with non-forfeitable dividend rights using the two class method.

No definition available.