Note 1 - Significant Accounting Policies (Details Textual) shares in Thousands	1 Months Ended	3 Months Ended
	Jun. 30, 2015 USD ($)	Mar. 31, 2017 USD ($) shares	Mar. 31, 2016 USD ($) shares	Dec. 31, 2016 USD ($)	Sep. 23, 2016 USD ($)	Dec. 31, 2015 USD ($)	Mar. 09, 2011 USD ($)
Long-term Line of Credit		$ 21,611,000		$ 22,777,000
Restricted Cash and Cash Equivalents, Current		2,798,000		1,546,000
Revenues		9,437,000	$ 4,820,000
Interest Expense, Debt		2,020,000	1,338,000
Amortization of Debt Issuance Costs		220,000	110,000
Interest Expense		2,100,000	$ 1,470,000
Lease Financing Obligation, Net of Current		$ 2,704,000		2,704,000
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares		2,762	1,330
Loss on Sale of Investments		$ 0
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax		0	$ 0
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivative, Loss on Derivative		1,543,000	2,753,000
Currency Hedge Agreement [Member]
Collateral Already Posted, Aggregate Fair Value		0		0
Birmingham Research Facility [Member]
Interest Expense		80,000	$ 132,000
Lease Financing Obligation, Net of Current		2,704,000		$ 2,704,000
Capital Leases, Future Minimum Payments Due		$ 4,662,000
RAPIVAB [Member] | Customer Concentration Risk [Member] | Sales Revenue, Product Line [Member]
Number of Major Customers		3
RAPIVAB [Member] | Customer Concentration Risk [Member] | Sales Revenue, Product Line [Member] | Three Customers [Member]
Concentration Risk, Percentage		90.00%
Agreement [Member] | CSL [Member] | RAPIVAB [Member]
Proceeds from License Fees Received	$ 33,740,000
Revenues	21,777,000
Milestone Payment Maximum	10,000,000
Agreement [Member] | CSL [Member] | RAPIVAB [Member] | Revenue from Sale of Inventory to be Recognized When the Inventory Transfer Is Complete [Member]
Deferred Revenue, Additions	3,740,000
Agreement [Member] | CSL [Member] | RAPIVAB [Member] | Regulatory Support Revenue for Canadian and EU Marketing Approvals, Portion Recognized Ratably Over Expected Period of Involvement [Member]
Deferred Revenue, Additions	1,223,000
Agreement [Member] | CSL [Member] | RAPIVAB [Member] | Contingent upon EU Marketing Approval [Member]
Proceeds from License Fees Received	$ 7,000,000
Computer Equipment [Member]
Property, Plant and Equipment, Useful Life		3 years
Laboratory Equipment, Office Equipment and Software [Member]
Property, Plant and Equipment, Useful Life		5 years
Furniture and Fixtures [Member]
Property, Plant and Equipment, Useful Life		7 years
Leasehold Improvements [Member] | Birmingham Research Facility [Member]
Property, Plant and Equipment, Useful Life		20 years 182 days
Property, Plant and Equipment, Gross						$ 1,589,000
Maximum [Member]
Maturity Period of High Quality Marketable Securities		3 years
Average Maturity Period of High Quality Marketable Securities		1 year 180 days
Maturity Period of Short Term Investment		1 year
Average Maturity for Portfolio Investments		1 year 180 days
Minimum [Member]
Maturity Period of Short Term Investment		90 days
Long-term Investment Maturity, Minimum		1 year
Royalty Receivable [Member]
Restricted Cash and Cash Equivalents, Current		$ 1,391,000
Collateral for Credit [Member]
Restricted Cash and Cash Equivalents, Current		1,407,000
Senior Credit Facility [Member] | MidCap Financial Services, LLC [Member]
Long-term Line of Credit		$ 23,000,000			$ 23,000,000
JPR Royalty Sub LLC [Member]
Revenue Recognition Royalty and Milestone Revenue Recognized							$ 30,000,000