Debt (Schedule Of Short-Term And Long-Term Balances Of Term Loan) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Dec. 01, 2017
Debt Instrument [Line Items]
Total loan balance	$ 252,418	$ 223,176
Less unamortized loan origination costs	(7,036)	(7,441)
Total loan balance	245,382	215,735
Less short-term loan balance	(1,155)	(1,164)
Long-term loan balance	244,227	214,571
2.45% Sparkasse Zollernalb (KFW Loan 1) [Member]
Debt Instrument [Line Items]
Total loan balance	974	1,061
1.40% Sparkasse Zollernalb (KFW Loan 2) [Member]
Debt Instrument [Line Items]
Total loan balance	1,506	1,615
Term Loan [Member]
Debt Instrument [Line Items]
Total loan balance	219,938	$ 220,500	$ 225,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total loan balance	$ 30,000