Note 1 - Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands		3 Months Ended
	Dec. 08, 2016	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Cash and Cash Equivalents, at Carrying Value		$ 126,306	$ 65,675	$ 138,909	$ 74,103
Cash and Cash Equivalents, Period Increase (Decrease)		$ (12,603)	$ (8,428)
Number of Years Cash is Sufficient to Fund Operations		1 year
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment		$ 1,038		$ 838
EXINI Diagnostics AB [Member]
Payments to Noncontrolling Interests	$ 368