Note 7 - Goodwill and Intangible Assets (Details Textual) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended	12 Months Ended
	May. 31, 2015	Apr. 30, 2014	Jun. 30, 2014	Mar. 31, 2016	Mar. 31, 2015
Other Acquisition [Member]
Goodwill, Acquired During Period		$ 2,800	$ 2,800
RadioPulse [Member]
Goodwill, Acquired During Period	$ 14,900
Goodwill, Impaired, Accumulated Impairment Loss				$ 13,192	$ 13,192
Goodwill, Acquired During Period				14,887	$ 2,781
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months				3,200
Finite-Lived Intangible Assets, Amortization Expense, Year Two				2,900
Finite-Lived Intangible Assets, Amortization Expense, Year Three				904
Finite-Lived Intangible Assets, Amortization Expense, Year Four				268
Finite-Lived Intangible Assets, Amortization Expense, Year Five				$ 240