Earnings 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
	Mar. 31, 2012	Mar. 31, 2011
Earnings Per Share [Abstract]
Income from continuing operations	$ 17,127	$ 15,490
Discontinued operations	1,223	3,603
Net income	$ 18,350	$ 19,093
Weighted average common shares outstanding, basic	27,776,104	27,696,727
Income from continuing operations per common share, basic	$ 0.62	$ 0.56
Discontinued operations per common share, basic	$ 0.04	$ 0.13
Net income per common share	$ 0.66	$ 0.69
Weighted average common shares outstanding, diluted	27,776,104	27,696,727
Stock options, diluted	27,118	97,235
Restricted shares, diluted	0	2,147
Average dilutive common shares outstanding	27,803,222	27,796,109
Income from continuing operations per common share	$ 0.62	$ 0.56
Discontinued operations per common share	$ 0.04	$ 0.13
Net income per common share	$ 0.66	$ 0.69
Stock options with an exercise price in excess of the market price for our common shares	11,681	11,130
Common Stock, Dividends, Per Share, Declared	$ 0.65	$ 0.615