Note 3 - Business Combinations (Details Textual) - USD ($) $ in Thousands			1 Months Ended		3 Months Ended		12 Months Ended			21 Months Ended
	May. 01, 2015	Jun. 27, 2013	May. 31, 2015	Apr. 30, 2014	Mar. 31, 2016	Jun. 30, 2014	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2016
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 Combination, Contingent Consideration Arrangements, Earnout Payment Period	3 years
Business Acquisition, Transaction Costs	$ 248
Employee Service Share-based Compensation, Cash Flow Effect, Cash Used to Settle Awards	249						$ 249
Business Acquisition, Adjustment to Accruals and Other Liabilities					$ (1,000)
Goodwill, Purchase Accounting Adjustments					(275)
Business Acquisition, Fair Value Adjustment to Intangible Assets					344
Business Acquisition, Fair Value Adjustment to Prepaid Expenses and Other Current Assets					$ (69)
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)
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	$ 15,658
Goodwill, Acquired During Period			$ 14,900
Acquired MCU Business [Member]
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual									$ 36,100
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net		$ 50,000
Payments to Acquire Businesses, Net of Cash Acquired		20,000
Business Acquisition, Cost of Acquired Entity Installment Payments Total		30,000
Business Acquisition, Cost of Acquired Entity Installment Payments Each Installment		$ 15,000
Business Combination, Acquisition Related Costs									403
Other Acquisition [Member]
Payments to Acquire Businesses, Net of Cash Acquired						$ 2,300
Cash Acquired from Acquisition						204
Goodwill, Acquired During Period				$ 2,800		2,800
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt						$ 723
Goodwill, Foreign Currency Translation Gain (Loss)										$ (477)
Payments to Acquire Businesses, Net of Cash Acquired							14,571	$ 2,297	$ 20,000
Goodwill, Acquired During Period							14,887	2,781
Goodwill, Foreign Currency Translation Gain (Loss)							$ 93	$ (570)