Note 13 - Segment and Geographic Distribution of Operations - Comparison of Total Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Total assets	$ 1,123,073	$ 1,251,177
Operating Segments [Member] | Americas [Member]
Total assets	293,998	338,649
Operating Segments [Member] | Middle East and Asia Pacific [Member]
Total assets	184,580	226,422
Operating Segments [Member] | Europe and Mediterranean [Member]
Total assets	289,123	302,214
Operating Segments [Member] | West Africa [Member]
Total assets	235,249	242,825
Corporate, Non-Segment [Member]
Total assets	$ 120,123	$ 141,067