Earnings Per Common Share (Reconciliation Of Numerators And Denominators ) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Basic EPS:
Net income	$ 25,019	$ 21,991	$ 71,163	$ 65,394
Less: income allocated to participating securities	(119)	0	(329)	0
Basic EPS per common share	$ 24,900	$ 21,991	$ 70,834	$ 65,394
Basic (in shares)	29,542,001	29,530,203	29,585,383	29,536,273
Basic (in dollars per share)	$ 0.84	$ 0.74	$ 2.39	$ 2.21
Diluted EPS:
Net income	$ 25,019	$ 21,991	$ 71,163	$ 65,394
Effect of Dilutive Securities	0	0	0	0
Diluted EPS per common share	$ 25,019	$ 21,991	$ 71,163	$ 65,394
Basic (in shares)	29,542,001	29,530,203	29,585,383	29,536,273
Effect of Dilutive Securities (in shares)	142,104	90,927	174,076	102,853
Diluted (in shares)	29,684,105	29,621,130	29,759,459	29,639,126
Diluted (in dollars per share)	$ 0.84	$ 0.74	$ 2.39	$ 2.21