Note 10 - Pension Plans - Information on Plan Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Mar. 31, 2016
Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan, Fair Value of Plan Assets	$ 39	$ 121
Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets	423	351
Fair Value, Inputs, Level 1 [Member] | Fixed Income Funds [Member]
Defined Benefit Plan, Fair Value of Plan Assets	1,244	1,225
Fair Value, Inputs, Level 1 [Member] | Mutual Fund [Member]
Defined Benefit Plan, Fair Value of Plan Assets	13,908	13,527
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets	15,614	15,224
Fair Value, Inputs, Level 2 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan, Fair Value of Plan Assets
Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets
Fair Value, Inputs, Level 2 [Member] | Fixed Income Funds [Member]
Defined Benefit Plan, Fair Value of Plan Assets	91	96
Fair Value, Inputs, Level 2 [Member] | Mutual Fund [Member]
Defined Benefit Plan, Fair Value of Plan Assets	13,626	13,394
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets	13,717	13,490
Cash and Cash Equivalents [Member]
Defined Benefit Plan, Fair Value of Plan Assets	39	121
Equity Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets	423	351
Fixed Income Funds [Member]
Defined Benefit Plan, Fair Value of Plan Assets	1,335	1,321
Mutual Fund [Member]
Defined Benefit Plan, Fair Value of Plan Assets	27,534	26,921
Defined Benefit Plan, Fair Value of Plan Assets	$ 29,331	$ 28,714