CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019
Statement of Financial Position [Abstract]
Accounts receivable, allowance	$ 946	$ 591
Property, plant and equipment, accumulated depreciation	$ 68,440	$ 65,548
Common shares, par value (USD per share)	$ 0.01	$ 0.01
Common shares, authorized (shares)	50,000,000	50,000,000
Common shares, issued (shares)	16,000,000	16,001,000
Preferred shares, par value (USD per share)	$ 0.01	$ 0.01
Preferred shares, authorized (shares)	10,000,000	10,000,000
Preferred shares, issued (shares)	0	0
Treasury shares, at cost (shares)	975,000	962,000

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount of allowance for credit loss on accounts receivable, classified as current.

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