Per Share Data (Calculation Of Basic And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Number of common share equivalent securities excluded from the diluted earnings per share calculation	2,500	1,900	2,500	1,500
Income from continuing operations attributable to common shareholders	$ 68,536	$ 31,023	$ 105,190	$ 141,753
Amount allocated to participating securities	(4,278)	(251)	(5,181)	(1,302)
Income from continuing operations attributable to common shareholders, net of amount allocated to participating securities	64,258	30,772	100,009	140,451
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	377,766	5,056	382,842	9,925
Net income attributable to common shareholders, as adjusted – basic	$ 442,024	$ 35,828	$ 482,851	$ 150,376
Earnings per common share from continuing operations	$ 0.72	$ 0.34	$ 1.12	$ 1.58
Earnings per common share from discontinued operations	4.22	0.06	4.28	0.11
Total earnings per common share – basic	$ 4.94	$ 0.40	$ 5.40	$ 1.69
Weighted average number of common shares outstanding – basic	89,559	89,153	89,451	89,071
Income allocated to common units from continuing operations	$ 0	$ 274	$ 0	$ 1,615
Income from continuing operations attributable to common shareholders, as adjusted	64,258	31,046	100,009	142,066
Net income attributable to common shareholders – diluted	$ 442,024	$ 36,102	$ 482,851	$ 151,991
Earnings per common share from continuing operations	$ 0.72	$ 0.34	$ 1.12	$ 1.57
Earnings per common share from discontinued operations	4.20	0.06	4.26	0.11
Total earnings per common share – diluted	$ 4.92	$ 0.40	$ 5.38	$ 1.68
Common share options and share awards granted	303	288	329	339
Common units	0	811	0	1,086
Weighted average number of common shares outstanding – diluted	89,862	90,252	89,780	90,496