Note 2 - Segment and Geographic Information (Details Textual) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2021 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)
Number of Operating Segments	2
Multi-client Data Library Impairment Charges	$ 0	$ 1,167
Goodwill, Impairment Loss	$ 0	$ 4,150	$ 4,150

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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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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