Earnings Per Share (Schedule Of Calculation Of Basic And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share Reconciliation [Line Items]
Net income (loss)	$ 7,369	$ (3,407)	$ 15,286	$ 445
Denominator for basic earnings per share – weighted-average number of common shares outstanding during the period	35,753	36,439	36,000	36,614
Denominator for diluted earnings per share	36,061	36,439	36,474	36,863
Basic earnings per share	$ 0.21	$ (0.09)	$ 0.42	$ 0.01
Diluted earnings per share	$ 0.20	$ (0.09)	$ 0.42	$ 0.01
Stock Options [Member]
Earnings Per Share Reconciliation [Line Items]
Incremental common shares attributable to exercise of dilutive options	45		49	49
Restricted Stock Units [Member]
Earnings Per Share Reconciliation [Line Items]
Incremental common shares attributable to exercise of dilutive options	263		425	200