Note 18 - Acquisition Activity - Fair Value of Identified Assets Acquired (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Oct. 12, 2016	Jul. 01, 2016
Assets acquired:
Goodwill, Ending Balance	$ 2,483,000	$ 2,483,000
Liabilities assumed:
Goodwill, Ending Balance	$ 2,483,000	$ 2,483,000
Imugen [Member]
Assets acquired:
Property and equipment				$ 655,000
Intangible assets				18,900,000
Net assets acquired				19,555,000
Goodwill, Ending Balance				2,645,000
Total consideration transferred				22,200,000
Liabilities assumed:
Net assets acquired				19,555,000
Goodwill, Ending Balance				2,645,000
Total consideration transferred				22,200,000
Imugen [Member] | Technology-Based Intangible Assets [Member]
Assets acquired:
Intangible assets				5,100,000
Imugen [Member] | Customer Relationships [Member]
Assets acquired:
Intangible assets				2,700,000
Imugen [Member] | Trademarks and Trade Names [Member]
Assets acquired:
Intangible assets				1,900,000
Imugen [Member] | In Process Research and Development, Indefinite Lived [Member]
Assets acquired:
Intangible assets				$ 9,200,000
Immunetics [Member]
Assets acquired:
Property and equipment			$ 787,000
Intangible assets			8,400,000
Net assets acquired			8,122,000
Goodwill, Ending Balance			1,322,000
Total consideration transferred			9,444,000
Cash			285,000
Accounts receivable, net			347,000
Inventory, net			375,000
Prepaid expenses and other assets			199,000
Total assets acquired			10,406,000
Liabilities assumed:
Accounts payable			(319,000)
Accrued liabilities			(739,000)
Other liabilities			(1,226,000)
Total liabilities assumed			(2,284,000)
Net assets acquired			8,122,000
Goodwill, Ending Balance			1,322,000
Total consideration transferred			9,444,000
Immunetics [Member] | Technology-Based Intangible Assets [Member]
Assets acquired:
Intangible assets			883,000
Immunetics [Member] | Customer Relationships [Member]
Assets acquired:
Intangible assets			350,000
Immunetics [Member] | Trade Names [Member]
Assets acquired:
Intangible assets			160,000
Immunetics [Member] | Grants [Member]
Assets acquired:
Intangible assets			50,000
Immunetics [Member] | In Process Research and Development, Indefinite Lived [Member]
Assets acquired:
Intangible assets			$ 6,970,000