Note 2 - Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Revenues	$ 5,942	$ 7,467	$ 17,716	$ 21,343
International [Member]
Revenues:
Revenues	2,310	2,649	6,522	7,088
International [Member] | Fair Value, Measurements, Recurring [Member]
Revenues:
Revenues	1,715	1,839	5,236	5,158
International [Member] | Fair Value, Measurements, Nonrecurring [Member]
Revenues:
Revenues	595	810	1,286	1,930
UNITED STATES
Revenues:
Revenues	3,632	4,818	11,194	14,255
UNITED STATES | Fair Value, Measurements, Recurring [Member]
Revenues:
Revenues	3,176	3,713	9,950	11,239
UNITED STATES | Fair Value, Measurements, Nonrecurring [Member]
Revenues:
Revenues	$ 456	$ 1,105	$ 1,244	$ 3,016