Note 1 - Significant Accounting Policies (Details Textual) - USD ($) shares in Thousands, $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Sep. 23, 2016	Dec. 31, 2015	Mar. 09, 2011
Long-term Line of Credit		$ 18,379		$ 18,379		$ 22,777
Restricted Cash and Cash Equivalents, Current		3,122		3,122		1,546
Loss on Sale of Investments				0
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax				0	$ 11
Revenues		8,760	$ 7,763	21,296	17,370
Interest Expense, Debt		2,140	1,465	6,334	4,356
Amortization of Debt Issuance Costs		219	116	658	335
Interest Expense		2,140	$ 1,465	6,334	$ 4,356
Lease Financing Obligation, Net of Current		$ 2,770		$ 2,770		2,704
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		1,996	1,291	2,519	1,190
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivative, Loss on Derivative				$ 1,858	$ 7,372
Derivative, Gain on Derivative				966	811
Currency Hedge Agreement [Member]
Collateral Already Posted, Aggregate Fair Value		$ 0		0		0
Birmingham Research Facility [Member]
Interest Expense		82	$ 86	217	$ 300
Lease Financing Obligation, Net of Current		2,704		2,704		$ 2,704
Capital Leases, Future Minimum Payments Due		4,444		4,444
RAPIVAB [Member]
Revenue Recognition, Milestone Method, Revenue Recognized				2,000,000
Supplemental NDA for RAPIVAB [Member]
Revenue Recognition, Milestone Method, Revenue Recognized				$ 5,000,000
Agreement [Member] | CSL [Member] | RAPIVAB [Member]
Proceeds from License Fees Received	$ 33,740
Revenues	21,777
Milestone Payment Maximum	5,000
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
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
Agreement [Member] | CSL [Member] | RAPIVAB [Member] | Contingent upon EU Marketing Approval [Member]
Proceeds from License Fees Received	$ 7,000
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
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]
Long-term Investment Maturity, Minimum				1 year
Royalty Receivable [Member]
Restricted Cash and Cash Equivalents, Current		1,713		$ 1,713
Collateral for Credit [Member]
Restricted Cash and Cash Equivalents, Current		1,409		1,409
Senior Credit Facility [Member] | MidCap Financial Services, LLC [Member]
Long-term Line of Credit		$ 23,000		$ 23,000			$ 23,000
JPR Royalty Sub LLC [Member]
Revenue Recognition Royalty and Milestone Revenue Recognized									$ 30,000