Note 3 - Acquisitions (Details Textual) - USD ($) $ in Thousands		4 Months Ended	6 Months Ended
	Sep. 05, 2017	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Payments to Acquire Businesses, Net of Cash Acquired			$ 10,644	$ 255,929
Trevigen Inc. [Member]
Payments to Acquire Businesses, Net of Cash Acquired	$ 10,600
Goodwill, Purchase Accounting Adjustments		$ 1,396
Trevigen Inc. [Member] \| Developed Technology Rights [Member]
Finite-Lived Intangible Asset, Useful Life	13 years
Trevigen Inc. [Member] \| Customer Relationships [Member]
Finite-Lived Intangible Asset, Useful Life	11 years
Trevigen Inc. [Member] \| Trade Names [Member]
Finite-Lived Intangible Asset, Useful Life	1 year 182 days