Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Note 8 - Plant Restructuring (Details Textual) - Closing of Northwest Plant [Member] - USD ($)	6 Months Ended	12 Months Ended
	Sep. 30, 2017	Mar. 31, 2017	Mar. 31, 2016
Restructuring Charges, Total	$ 57,000		$ 10,302,000
Restructuring Reserve, Accrual Adjustment		$ 1,829,000
Employee Severance [Member]
Restructuring Charges, Total			162,000
Restructuring Reserve, Accrual Adjustment		1,578,000
Impairment of Long-Lived Assets [Member]
Restructuring Charges, Total			5,065,000
Restructuring Reserve, Accrual Adjustment		(384,000)
Other Restructuring [Member]
Restructuring Charges, Total			$ 5,075,000
Restructuring Reserve, Accrual Adjustment		$ 635,000