Commitments and Contingencies (Narrative) (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Apr. 07, 2016
Loss Contingencies [Line Items]
Lymphoseek sales revenue	$ 3,782,680	$ 1,835,422	$ 10,300,000
Capital Royalty Partners II LP [Member]
Loss Contingencies [Line Items]
Debt instrument default interest rate percentage	18.00%
Minimum sales revenue target	$ 22,500,000		11,000,000
Reduced minimum sales revenue target in 2015			$ 10,000,000
Capital Royalty Partners II LP [Member] \| Subsequent Event [Member]
Loss Contingencies [Line Items]
Debt instrument default interest rate percentage				18.00%