Note 3 - Business Combinations (Details Textual) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended		11 Months Ended	12 Months Ended
	May 01, 2015	May 31, 2015	Dec. 31, 2016	Jun. 30, 2014	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Impairment of Intangible Assets, Finite-lived			$ 1,400			$ 1,391
Payments to Acquire Businesses, Net of Cash Acquired							14,472	$ 2,297
Goodwill, Acquired During Period		$ 14,900					14,887
Goodwill, Foreign Currency Translation Gain (Loss)						(128)	93
RadioPulse [Member]
Business Combination, Consideration Transferred	$ 15,700
Payments to Acquire Businesses, Gross	14,700
Business Combination, Consideration Transferred, Other	1,000
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	6,000
Business Acquisition, Transaction Costs	248
Employee Service Share-based Compensation, Cash Flow Effect, Cash Used to Settle Awards	249						$ 249
Business Combination, Contingent Consideration, Liability	$ 0					0
Impairment of Intangible Assets, Finite-lived			$ 1,400
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual					$ 4,100
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual					$ (3,600)
Other Acquisition [Member]
Payments to Acquire Businesses, Net of Cash Acquired				$ 2,300
Cash Acquired from Acquisition				204
Goodwill, Acquired During Period				2,800
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt				$ 723
Goodwill, Foreign Currency Translation Gain (Loss)						$ (605)