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Note 2 - Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2019
Capitalized Computer Software, Net, Ending Balance	$ 49,400	$ 32,700	$ 16,700
Goodwill, Impairment Loss	0
Advertising Expense	11,500	13,000	11,800
Research and Development Expense, Total	36,940	32,692	$ 28,735
Operating Lease, Right-of-Use Asset	9,855	11,425
Operating Lease, Liability, Total	$ 10,858	$ 11,905
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset				$ 13,100
Building [Member]
Property, Plant and Equipment, Useful Life (Year)	39 years
Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)	3 years
Finite-Lived Intangible Asset, Useful Life (Year)	2 years
Minimum [Member] \| Equipment [Member]
Property, Plant and Equipment, Useful Life (Year)	3 years
Minimum [Member] \| Office Furniture And Equipment [Member]
Property, Plant and Equipment, Useful Life (Year)	3 years
Minimum [Member] \| Computer Equipment [Member]
Property, Plant and Equipment, Useful Life (Year)	3 years
Minimum [Member] \| Land, Buildings and Improvements [Member]
Property, Plant and Equipment, Useful Life (Year)	10 years
Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)	39 years
Finite-Lived Intangible Asset, Useful Life (Year)	10 years
Maximum [Member] \| Equipment [Member]
Property, Plant and Equipment, Useful Life (Year)	15 years
Maximum [Member] \| Office Furniture And Equipment [Member]
Property, Plant and Equipment, Useful Life (Year)	7 years
Maximum [Member] \| Computer Equipment [Member]
Property, Plant and Equipment, Useful Life (Year)	5 years
Maximum [Member] \| Land, Buildings and Improvements [Member]
Property, Plant and Equipment, Useful Life (Year)	39 years