Note 7 - Goodwill and Intangible Assets (Details Textual)		3 Months Ended					12 Months Ended
	Nov. 06, 2018 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2018 USD ($)	Oct. 12, 2016 USD ($)
Number of Reporting Units							1
Disposal Group, Including Discontinued Operation, Goodwill										$ 1,500,000
Goodwill, Ending Balance		$ 2,483,000	$ 2,483,000				$ 2,483,000	$ 2,483,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life							9 years 255 days
Amortization of Intangible Assets, Total							$ 93,000	206,000	$ 71,000
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months		22,000					22,000
Finite-Lived Intangible Assets, Amortization Expense, Year Three		17,000					17,000
Impairment of Intangible Assets (Excluding Goodwill), Total			7,200,000				879,000	$ 18,300,000	$ 1,765,000
Goodwill, Impairment Loss		0
Finite-Lived Intangible Assets, Amortization Expense, Year Two		22,000					22,000
Quest [Member]
Proceeds from Divestiture of Businesses	$ 170,000,000
Customer Relationships [Member]
Impairment of Intangible Assets (Excluding Goodwill), Total				$ 1,100,000
Trade Names [Member]
Impairment of Intangible Assets (Excluding Goodwill), Total				701,000
In Process Research and Development Member 1 [Member]
Impairment of Intangible Assets (Excluding Goodwill), Total				9,200,000
Immunetics Intangibles [Member]
Impairment of Intangible Assets, Finite-lived		$ 879,000
Immunetics [Member]
Goodwill, Ending Balance											$ 1,322,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Inventory					$ (45,000)
Goodwill, Purchase Accounting Adjustments					22,500
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments Related to Current Period, Income Tax Expense					58,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments Related to Current Period, Cost of Product Revenue					(44,000)
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments Related to Current Period, Sales and Marketing Expense					(26,000)
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)						$ 1,400,000
Impairment of Intangible Assets (Excluding Goodwill), Total				$ 11,100,000
Goodwill, Impairment Loss							$ 0
Immunetics [Member] | Customer Relationships [Member]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles					(50,000)
Impairment of Intangible Assets (Excluding Goodwill), Total			98,000
Immunetics [Member] | Trade Names [Member]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles					(130,000)
Impairment of Intangible Assets (Excluding Goodwill), Total			166,000
Immunetics [Member] | Technology-Based Intangible Assets [Member]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles					$ 22,500
Immunetics [Member] | In Process Research and Development [Member]
Impairment of Intangible Assets (Excluding Goodwill), Total			$ 7,000,000