Note 5 - Stockholders' Equity - Dividends (Details) - USD ($) $ / shares in Units, $ in Thousands					12 Months Ended
Dec. 14, 2020	Sep. 09, 2020	Jun. 11, 2020	Apr. 07, 2020	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Record Date	Dec. 29, 2020	Sep. 23, 2020	Jun. 25, 2020	Apr. 22, 2020
Payable	Jan. 07, 2021	Sep. 30, 2020	Jul. 07, 2020	Apr. 29, 2020
Amount	$ 1,450	$ 1,451	$ 1,448	$ 1,431	$ 5,780	$ 5,617	$ 5,479
Common Class A [Member]
Dividend (in dollars per share)	$ 0.072	$ 0.072	$ 0.072	$ 0.072
Common Class B [Member]
Dividend (in dollars per share)	$ 0.06	$ 0.06	$ 0.06	$ 0.06

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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=121583591&loc=d3e4304-108586

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Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

+ References

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=120397183&loc=d3e187085-122770

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The per share amount of a dividend declared, but not paid, as of the financial reporting date.

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Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

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