Per Share Data (Calculation Of Basic And Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Earnings Per Share [Abstract]
Number of common share equivalent securities excluded from the diluted earnings per share calculation	2,100,000	3,000,000
Income from continuing operations attributable to common shareholders	$ 40,036	$ 29,012
Amount allocated to participating securities	(352)	(638)
Income from continuing operations attributable to common shareholders, net of amount allocated to participating securities	39,684	28,374
Income from discontinued operations, including gain on sale, attributable to common shareholders	0	34,464
Net income attributable to common shareholders, as adjusted	39,684	62,838
Income from continuing operations attributable to common shareholders, as adjusted – per share	$ 0.45	$ 0.33
Income from discontinued operations, including gain on sale, attributable to common shareholders – per share	$ 0.00	$ 0.39
Net income attributable to common shareholders, as adjusted – per share	$ 0.45	$ 0.72
Weighted average number of common shares outstanding – basic	87,651,000	86,703,000
Income allocated to common units from continuing operations	310	0
Income from continuing operations attributable to common shareholders, as adjusted	39,994	28,374
Net income attributable to common shareholders, as adjusted	$ 39,994	$ 62,838
Income from continuing operations attributable to common shareholders, as adjusted – per share	$ 0.45	$ 0.33
Income from discontinued operations, including gain on sale, attributable to common shareholders – per share	$ 0.00	$ 0.39
Net income attributable to common shareholders, as adjusted – per share	$ 0.45	$ 0.72
Common share options and share awards granted	360,000	573,000
Common units	813,000	0
Weighted average number of common shares outstanding – diluted	88,824,000	87,276,000