Note 12 - Stockholders' Equity - Dividend Activity (Details) - USD ($) $ / shares in Units, $ in Thousands							3 Months Ended	6 Months Ended
May 20, 2020	Mar. 03, 2020	Nov. 20, 2019	Aug. 21, 2019	May 22, 2019	Mar. 22, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Payment date	Jun. 04, 2020	Mar. 19, 2020	Dec. 05, 2019	Sep. 05, 2019	Jun. 05, 2019	Apr. 05, 2019
Per share amount (in dollars per share)	$ 0.095	$ 0.095	$ 0.085	$ 0.085	$ 0.085	$ 0.085	$ 0.095	$ 0.085	$ 0.190	$ 0.170
Dividend payment	$ 1,917	$ 1,917	$ 1,701	$ 1,691	$ 1,672	$ 1,672

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

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-Name Accounting Standards Codification
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Date the declared dividend will be paid, in CCYY-MM-DD format.

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Carrying value as of the balance sheet date of dividends declared but unpaid on equity securities issued by the entity and outstanding. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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