Note 4 - Business Combinations - Allocation of Purchase Price for the Acquisition of Rapid (Details) - USD ($) $ in Thousands		9 Months Ended
	Jan. 22, 2021	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Assets acquired:
Goodwill		$ 404,240		$ 128,752
Liabilities assumed:
Net cash consideration		127,413	$ (0)
Acquired 3D Hubs [Member]
Assets acquired:
Current assets		2,497
Intangible assets		30,770
Goodwill		281,845
Other long-term assets		1,139
Total assets acquired		316,251
Liabilities assumed:
Current contingent consideration		7,093
Current liabilities		5,666
Long-term contingent consideration		6,507
Long-term deferred tax liabilities		2,608
Other long-term liabilities		255
Total liabilities assumed		22,129
Net assets acquired		294,122
Payments to Acquire Businesses, Gross		133,847
Cash acquired		(6,434)
Net cash consideration	$ 127,400	127,413
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	166,700	166,709
Total purchase consideration	$ 294,100	$ 294,122