Note 9 - Borrowing Arrangements (Details Textual) € in Thousands, $ in Thousands					3 Months Ended	9 Months Ended
	Nov. 20, 2015 USD ($)	Apr. 01, 2015 EUR (€)	Dec. 06, 2013 USD ($)	Jun. 10, 2005 EUR (€)	Sep. 30, 2014 USD ($)	Dec. 31, 2015 EUR (€)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2015 USD ($)	May. 01, 2015 USD ($)	Apr. 01, 2015 USD ($)	Mar. 31, 2015 EUR (€)	Mar. 31, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 10, 2005 USD ($)
Bank of West Amended and Restated Credit Agreement December Six Two Thousand and Thirteen [Member]
Line of Credit Facility, Initiation Date			Dec. 06, 2013
Line of Credit Facility, Expiration Date			Nov. 30, 2015
Line of Credit Facility, Maximum Borrowing Capacity			$ 50,000
Repayments of Lines of Credit							$ 45,000
Bank of West Amended and Restated Credit Agreement November 20, 2015 [Member] | Minimum [Member]
Line of Credit Facility Basis Spread on Variable Rate						0.75%			0.75%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage						0.25%	0.25%
Bank of West Amended and Restated Credit Agreement November 20, 2015 [Member] | Maximum [Member]
Line of Credit Facility Basis Spread on Variable Rate						2.50%			2.50%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage						0.625%	0.625%
Bank of West Amended and Restated Credit Agreement November 20, 2015 [Member]
Line of Credit Facility, Initiation Date	Nov. 20, 2015
Line of Credit Facility, Expiration Date	Nov. 20, 2017
Debt Instrument, Term	2 years
Line of Credit Facility, Maximum Borrowing Capacity	$ 125,000
Line of Credit Facility, Interest Rate at Period End						2.42%			2.42%
Long-term Line of Credit									$ 80,000
Deferred Finance Costs, Net	371								350
Amortization of Financing Costs							$ 21
Available Credit Line for Letter of Credit	$ 10,000								10,000
IKB Deutsche Industrial Bank Loan Payable [Member]
Debt Instrument, Issuance Date				Jun. 10, 2005
Debt Instrument, Face Amount				€ 10,000											$ 12,200
Long-term Debt, Gross												€ 3,500	$ 3,800
April 2015 IKB Deutsche Industriebank Loan Payable [Member]
Debt Instrument, Maturity Date		Mar. 31, 2022
Debt Instrument, Face Amount		€ 6,500									$ 7,000
Long-term Debt, Gross						€ 5,800			6,300
Debt Instrument, Interest Rate, Stated Percentage		1.75%									1.75%
Debt Instrument, Periodic Payment, Principal						€ 232	253
Notes Payable, Other Payables [Member] | RadioPulse [Member]
Long-term Debt, Gross									$ 1,700
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt										$ 2,400
Debt Instrument, Interest Rate, Effective Percentage										4.90%
Notes Payable, Other Payables [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt														$ 723
Repayments of Debt					$ 99
Repayments of Debt							$ 46,247	$ 914