Nature Of Operations And Accounting Policies (Schedule of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Total equity, beginning balance	$ 812,514	$ 853,842	$ 753,361
Other comprehensive income (loss)	(1,151)	(16)	(391)
Income tax (expense) benefit	1	(68)	22
Total equity, ending balance	845,417	812,514	853,842
Foreign Currency Translation Adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Total equity, beginning balance	(1,065)	(914)	(545)
Other comprehensive income (loss)	(194)	(83)	(391)
Income tax (expense) benefit	1	(68)	22
Total equity, ending balance	(1,258)	(1,065)	(914)
Derivative Gains (Losses) on Cash Flow Hedges, net
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Total equity, beginning balance	67	0	0
Other comprehensive income (loss)	(957)	67	0
Income tax (expense) benefit	0	0	0
Total equity, ending balance	(890)	67	0
Accumulated Other Comprehensive Loss
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Total equity, beginning balance	(998)	(914)	(545)
Other comprehensive income (loss)	(1,151)	(16)	(391)
Income tax (expense) benefit	1	(68)	22
Total equity, ending balance	(2,148)	(998)	(914)
Other Comprehensive Loss
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Total equity, beginning balance	(84)	(369)
Total equity, ending balance	$ (1,150)	$ (84)	$ (369)