Earnings Per Share (Schedule Of Earnings Per Share, Basic And Diluted) (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
Numerator
Net income	$ 27,024	$ 17,048	$ 59,636	$ 70,261
Less: Undistributed earnings allocated to participating securities				(58)
Net income allocable to common stockholders	$ 27,024	$ 17,048	$ 59,636	$ 70,203
Denominator
Weighted average common shares outstanding - basic	30,587,487	30,232,376	30,378,860	29,885,858
Dilutive effect of restricted stock units	318,748	322,505	262,334	303,200
Weighted average common shares outstanding - diluted	30,906,235	30,554,881	30,641,194	30,189,058
Earnings per share:
Basic	$ 0.88	$ 0.56	$ 1.96	$ 2.35
Diluted	$ 0.87	$ 0.56	$ 1.95	$ 2.33