Note 11 - Segment Reporting - Revenue From Operations by Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Revenue	$ 115,108	$ 113,452
Operating Segments [Member]
Revenue	115,108	113,452
Operating Segments [Member] \| United States Segment [Member]
Revenue	90,076	87,811
Operating Segments [Member] \| Europe Segment [Member]
Revenue	20,787	21,254
Operating Segments [Member] \| Japan Segment [Member]
Revenue	$ 4,245	$ 4,387

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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+ Details