Note 3 - Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue:
Revenue	$ 434,395	$ 458,728	$ 445,596
Injection Molding (Protomold) [Member]
Revenue:
Revenue	217,992	217,415	210,523
CNC Machining (Firstcut) [Member]
Revenue:
Revenue	131,587	155,473	153,521
3D Printing (Fineline) [Member]
Revenue:
Revenue	62,502	61,352	53,342
Sheet Metal [Member]
Revenue:
Revenue	18,838	21,000	24,998
Other Products [Member]
Revenue:
Revenue	3,476	3,488	3,212
UNITED STATES
Revenue:
Revenue	345,708	360,205	350,535
Europe [Member]
Revenue:
Revenue	74,796	82,805	80,889
JAPAN
Revenue:
Revenue	$ 13,891	$ 15,718	$ 14,172