Note 7 - Goodwill (Details Textual) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Mar. 31, 2018	Sep. 30, 2017
Goodwill, Useful Life for Tax Purposes			15 years
Goodwill, Impairment Loss	$ 0	$ 0		$ 0

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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