Note 3 - Acquisitions - Acquired Intangible Assets (Details) - USD ($) $ in Thousands				9 Months Ended
	Nov. 11, 2019	Aug. 08, 2019	Apr. 01, 2019	Sep. 30, 2020	Nov. 12, 2019	Aug. 07, 2019	Mar. 31, 2019
Intangible assets, estimated useful life (Year)				9 years
Astero [Member]
Intangible assets			$ 4,120
Astero [Member] | Customer Relationships [Member]
Intangible assets			$ 160				$ 160
Intangible assets, estimated useful life (Year)			4 years
Astero [Member] | Trade Names [Member]
Intangible assets			$ 470				470
Intangible assets, estimated useful life (Year)			9 years
Astero [Member] | Developed Technology Rights [Member]
Intangible assets			$ 2,840				2,840
Astero [Member] | Developed Technology Rights [Member] | Minimum [Member]
Intangible assets, estimated useful life (Year)			5 years
Astero [Member] | Developed Technology Rights [Member] | Maximum [Member]
Intangible assets, estimated useful life (Year)			9 years
Astero [Member] | In Process Research and Development [Member]
Intangible assets			$ 650				$ 650
Intangible assets, estimated useful life (Year)			9 years
SAVSU [Member]
Intangible assets		$ 12,150
SAVSU [Member] | Customer Relationships [Member]
Intangible assets		$ 80				$ 80
Intangible assets, estimated useful life (Year)		6 years
SAVSU [Member] | Trade Names [Member]
Intangible assets		$ 1,320				1,320
Intangible assets, estimated useful life (Year)		9 years
SAVSU [Member] | Developed Technology Rights [Member]
Intangible assets						$ 10,750
SAVSU [Member] | Technology-Based Intangible Assets [Member]
Intangible assets		$ 10,750
SAVSU [Member] | Technology-Based Intangible Assets [Member] | Minimum [Member]
Intangible assets, estimated useful life (Year)		7 years
SAVSU [Member] | Technology-Based Intangible Assets [Member] | Maximum [Member]
Intangible assets, estimated useful life (Year)		8 years
CBS Acquisition [Member]
Intangible assets	$ 6,790				$ 6,800
CBS Acquisition [Member] | Customer Relationships [Member]
Intangible assets	$ 560
Intangible assets, estimated useful life (Year)	6 years
CBS Acquisition [Member] | Trade Names [Member]
Intangible assets	$ 800
Intangible assets, estimated useful life (Year)	6 years
CBS Acquisition [Member] | Developed Technology Rights [Member]
Intangible assets	$ 5,430
Intangible assets, estimated useful life (Year)	9 years