Note 10 - Pension Plans - Information on Plan Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Mar. 31, 2015
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets	$ 2,798	$ 2,588
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Fair Value of Plan Assets
Cash and Cash Equivalents [Member]
Defined Benefit Plan, Fair Value of Plan Assets	$ 2,798	$ 2,588
Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets
Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets	$ 38	$ (30)
Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Fair Value of Plan Assets
Foreign Exchange Contract [Member]
Defined Benefit Plan, Fair Value of Plan Assets	$ 38	$ (30)
Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets	20,814	19,997
Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets	43	652
Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Fair Value of Plan Assets	14	7
Equity Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets	20,871	20,656
Fixed Income Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets	1,042	861
Fixed Income Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets	$ 5,739	5,887
Fixed Income Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		1
Fixed Income Funds [Member]
Defined Benefit Plan, Fair Value of Plan Assets	$ 6,781	$ 6,749
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets	$ 14	$ 16
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Fair Value of Plan Assets
Collateralized Mortgage Backed Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets	$ 14	$ 16
Other Contract [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		2
Other Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets	$ 82	$ 133
Other Contract [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Fair Value of Plan Assets
Other Contract [Member]
Defined Benefit Plan, Fair Value of Plan Assets	$ 82	$ 135
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets	24,654	23,448
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets	5,916	6,658
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Fair Value of Plan Assets	14	8
Defined Benefit Plan, Fair Value of Plan Assets	$ 30,584	$ 30,114