Fair Value Measurements (Schedule Of Fair Values Of Financial Instruments Measured On Recurring Basis) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Total assets	$ 65,853	$ 23,198
Business Combination, Contingent Consideration, Liability	23,800	20,477
Derivative Liability	768	768
Financial Liabilities Fair Value Disclosure	24,568	21,245
Corporate Debt Securities [Member]
Investments, Fair Value Disclosure	20,245	22,745
Money Market Funds [Member]
Cash	45,608	453
Level 1 [Member]
Total assets	45,608	453
Business Combination, Contingent Consideration, Liability	0	0
Derivative Liability	0	0
Financial Liabilities Fair Value Disclosure	0	0
Level 1 [Member] | Corporate Debt Securities [Member]
Investments, Fair Value Disclosure	0	0
Level 1 [Member] | Money Market Funds [Member]
Cash	45,608	453
Level 2 [Member]
Total assets	20,245	22,745
Business Combination, Contingent Consideration, Liability	0	0
Derivative Liability	768	768
Financial Liabilities Fair Value Disclosure	768	768
Level 2 [Member] | Corporate Debt Securities [Member]
Investments, Fair Value Disclosure	20,245	22,745
Level 2 [Member] | Money Market Funds [Member]
Cash	0	0
Level 3 [Member]
Total assets	0	0
Business Combination, Contingent Consideration, Liability	23,800	20,477
Derivative Liability	0	0
Financial Liabilities Fair Value Disclosure	23,800	20,477
Level 3 [Member] | Corporate Debt Securities [Member]
Investments, Fair Value Disclosure	0	0
Level 3 [Member] | Money Market Funds [Member]
Cash	$ 0	$ 0