Earnings and Dividends Per Share (Summary Of 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, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share [Abstract]
Income from continuing operations attributable to common stockholders	$ 22,812	$ 13,283	$ 56,717	$ 46,359
Income from discontinued operations	19,932	1,068	21,691	3,269
Net income attributable to common stockholders	$ 42,744	$ 14,351	$ 78,408	$ 49,628
Weighted Average Number of Shares Outstanding, Basic	27,876,176	27,830,311	27,872,805	27,799,750
Income from continuing operations per common share, basic	$ 0.82	$ 0.48	$ 2.03	$ 1.66
Discontinued operations per common share, basic	$ 0.71	$ 0.04	$ 0.78	$ 0.12
Net income per common share attributable to common stockholders	$ 1.53	$ 0.52	$ 2.81	$ 1.78
Weighted average common shares outstanding, diluted	27,876,176	27,830,311	27,872,805	27,799,750
Stock options, diluted	29,369	32,271	34,109	29,129
Average dilutive common shares outstanding	27,905,545	27,862,582	27,906,914	27,828,879
Income from continuing operations per common share	$ 0.82	$ 0.48	$ 2.03	$ 1.66
Discontinued operations per common share	$ 0.71	$ 0.04	$ 0.78	$ 0.12
Net income per common share attributable to common stockholders	$ 1.53	$ 0.52	$ 2.81	$ 1.78
Stock options with an exercise price in excess of the market price for our common shares	43,473	917	15,649	1,972
Common Stock, Dividends, Per Share, Declared	$ 0.735	$ 0.67	$ 2.165	$ 1.97