Earnings per Common Share (Reconciliation Of Number Of Common Shares Used In Calculating Basic And Diluted EPS) (Details) (USD $) In Thousands, except Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Earnings per Share [Line Items]
Earnings from continuing operations	$ 25,599	$ 18,164	$ 41,744	$ 31,376
Basic average common shares outstanding (in shares)	40,187,334	40,000,396	40,147,133	39,954,008
Diluted average common shares outstanding (in shares)	40,380,302	40,233,863	40,359,877	40,194,470
Basic earnings per common share from continuing operations (in dollars per share)	$ 0.64	$ 0.45	$ 1.04	$ 0.79
Diluted earnings per common share from continuing operations (in dollars per share)	$ 0.63	$ 0.45	$ 1.03	$ 0.78
Total anti-dilutive shares excluded from the calculation (in shares)	77,767	81,912	80,467	85,712
Common stock options [Member]
Earnings per Share [Line Items]
Incremental shares (in shares)	44,147	95,335	54,048	95,595
Performance shares [Member]
Earnings per Share [Line Items]
Incremental shares (in shares)	120,182	108,097	129,691	115,739
Total anti-dilutive shares excluded from the calculation (in shares)	77,767	81,162	77,767	81,162
Restricted stock units [Member]
Earnings per Share [Line Items]
Incremental shares (in shares)	28,639	30,035	29,005	29,128
Total anti-dilutive shares excluded from the calculation (in shares)	0	750	2,700	4,550