Earnings Per Common Share (Reconciliation Of Numerators And Denominators ) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Basic EPS:
Net income	$ 16,352	$ 23,859	$ 34,532	$ 46,144
Less: income allocated to participating securities	(96)	(114)	(200)	(227)
Basic EPS per common share	$ 16,256	$ 23,745	$ 34,332	$ 45,917
Basic (in shares)	28,799,828	29,626,931	29,015,308	29,607,074
Basic (in dollars per share)	$ 0.56	$ 0.80	$ 1.18	$ 1.55
Diluted EPS:
Net income	$ 16,352	$ 23,859	$ 34,532	$ 46,144
Effect of Dilutive Securities	0	0	0	0
Diluted EPS per common share	$ 16,352	$ 23,859	$ 34,532	$ 46,144
Basic (in shares)	28,799,828	29,626,931	29,015,308	29,607,074
Effect of Dilutive Securities (in shares)	169,900	170,010	169,113	201,785
Diluted (in shares)	28,969,728	29,796,941	29,184,421	29,808,859
Diluted (in dollars per share)	$ 0.56	$ 0.80	$ 1.18	$ 1.55