Note 16 - Defined Contribution Retirement Plan (Details Textual)	12 Months Ended
Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)
Defined Contribution Plan, Service Period for Eligibility	1 year
Defined Contribution Plan, Employee, Eligible Age	18
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	3.00%
Defined Contribution Plan, Cost	$ 174,065	$ 145,082

Amount of cost for defined contribution plan.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration