Note 11 - Subsequent Events (Details Textual) - $ / shares		12 Months Ended
May 01, 2019	Mar. 31, 2019	Mar. 31, 2018
Common Stock, Dividends, Per Share, Declared		$ 4	$ 4
Subsequent Event [Member]
Common Stock, Dividends, Per Share, Declared	$ 1
Subsequent Event [Member] \| Common Stock [Member]
Dividends Payable, Date to be Paid	May 31, 2019
Dividends Payable, Date of Record	May 13, 2019

Aggregate dividends declared during the period for each share of common stock outstanding.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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Date the declared dividend will be paid, in CCYY-MM-DD format.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
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