Note 20 - Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($)	Mar. 31, 2019	Mar. 31, 2018
Accrued vacation	$ 322,000	$ 343,000
Property and equipment		264,000
Accounts and notes receivable reserve	115,000	103,000
Employee severance reserve		549,000
Net operating loss carryforwards	7,516,000	6,083,000
Federal/Canadian tax credits	4,486,000	4,486,000
Unrealized gains/losses	833,000	2,324,000
Outside basis difference on CFCs	1,431,000
Investments in partnerships	534,000
Disallowed capital loss	463,000
Other deferred tax assets	301,000	236,000
Total deferred tax assets	16,001,000	14,388,000
Prepaid expenses	(115,000)	(337,000)
263A inventory capitalization		(28,000)
Inventory basis difference	(434,000)	(179,000)
Property and equipment	(233,000)
Investments in partnerships		(270,000)
Other deferred tax liabilities	(83,000)	(83,000)
Total deferred tax liabilities	(865,000)	(897,000)
Net deferred tax asset	15,136,000	13,491,000
Less valuation allowance	(14,658,000)	(13,583,000)
Net deferred tax liability	$ 478,000
Net deferred tax asset		$ (92,000)