Convertible Debt (Schedule Of Interest Expense Recognized) (Details) - 3.375% Convertible Notes [Member] - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Debt Instrument [Line Items]
3.375% contractual coupon		$ 1,814	$ 1,814
Amortization of debt discount		1,272	1,193
Amortization of debt issuance costs		219	165
Additional interest on Convertible Notes	[1]		1,370
Interest expense		$ 3,305	$ 4,542
Interest rate		3.375%

[1] During the three months ended March 31, 2019, additional nonrecurring interest expense was incurred pursuant to the notes’ indenture related to the removal of the restrictive legend and assignment of the unrestricted CUSIP on the Convertible Notes.