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		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Earnings Per Share [Abstract]
Income from continuing operations	$ 15,681	$ 23,842	$ 32,808	$ 39,332
Discontinued operations	1,247	1,275	2,470	4,878
Net income	$ 16,928	$ 25,117	$ 35,278	$ 44,210
Weighted average common shares outstanding, basic	27,792,834	27,708,136	27,784,469	27,702,432
Income from continuing operations per common share, basic	$ 0.56	$ 0.86	$ 1.18	$ 1.42
Discontinued operations per common share, basic	$ 0.05	$ 0.04	$ 0.09	$ 0.17
Net income per common share	$ 0.61	$ 0.90	$ 1.27	$ 1.59
Weighted average common shares outstanding, diluted	27,792,834	27,708,136	27,784,469	27,702,432
Stock options, diluted	27,997	90,145	27,558	93,690
Restricted shares, diluted	0	1,335	0	1,741
Average dilutive common shares outstanding	27,820,831	27,799,616	27,812,027	27,797,863
Income from continuing operations per common share	$ 0.56	$ 0.86	$ 1.18	$ 1.42
Discontinued operations per common share	$ 0.05	$ 0.04	$ 0.09	$ 0.17
Net income per common share	$ 0.61	$ 0.90	$ 1.27	$ 1.59
Stock options with an exercise price in excess of the market price for our common shares	11,026	23,123	14,559	9,735
Common Stock, Dividends, Per Share, Declared	$ 0.65	$ 0.615	$ 1.30	$ 1.23