Note 16 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Effective Income Tax Rate Reconciliation, Percent	26.00%	37.00%	22.00%
Effective Income Tax Rate Reconciliation, Out of Period Adjustments, Percent		6.00%
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 1,100	$ (436)
Operating Loss Carryforwards, Valuation Allowance	16,400
Unrecognized Tax Benefits	6,443	6,946	$ 6,952	$ 6,978
Unrecognized Tax Benefits, Period Increase (Decrease)	(503)
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	952
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued, Reversal	94
Unrecognized Tax Benefits, Increase (Decrease) in Income Tax Penalties and Interest Accrued	438
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued, Reversal During Period	532
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	3,000	4,100
Undistributed Earnings of Foreign Subsidiaries	150,500
Cash and Cash Equivalents, at Carrying Value	167,904	$ 155,806
Geographic Distribution, Foreign [Member]
Cash and Cash Equivalents, at Carrying Value	74,000
Domestic Tax Authority [Member]
Operating Loss Carryforwards	23,400
Foreign Tax Authority [Member]
Operating Loss Carryforwards	$ 18,600