Note 13 - Acquisitions - Fair Value of Net Assets Acquired (Details) - USD ($)			3 Months Ended
	Nov. 11, 2019	Apr. 01, 2019	Mar. 31, 2019	Dec. 31, 2019	Nov. 12, 2019	Sep. 30, 2019	Aug. 08, 2019	Aug. 07, 2019	Jun. 30, 2019	Dec. 31, 2018
Intangible assets			$ 4,120,000
Goodwill				$ 33,637,000		$ 28,342,000			$ 9,515,000
Intangible assets, estimated fair value				$ 21,982,000
Astero [Member]
Cash and cash equivalents		$ 11,000
Accounts receivable, net		154,000
Inventory		456,000
Goodwill		9,515,000
Other assets		99,000
Accounts Payable		(250,000)
Other liabilities		164,000
Fair value of net assets acquired		13,941,000
Other liabilities		(164,000)
Fair value of net assets acquired		13,941,000
Inventory		456,000
Intangible assets, estimated fair value		12,150,000
Astero [Member] | Customer Relationships [Member]
Intangible assets		$ 160,000	$ 160,000
Intangible assets (Year)		6 years	4 years
Intangible assets, estimated fair value		$ 80,000
Intangible assets, estimated useful life (Year)		6 years	4 years
Astero [Member] | Customer Relationships [Member] | Minimum [Member]
Intangible assets (Year)
Intangible assets, estimated useful life (Year)
Astero [Member] | Trade Names [Member]
Intangible assets		$ 470,000	$ 470,000
Intangible assets (Year)		9 years	9 years
Intangible assets, estimated fair value		$ 1,320,000
Intangible assets, estimated useful life (Year)		9 years	9 years
Astero [Member] | Trade Names [Member] | Minimum [Member]
Intangible assets (Year)
Intangible assets, estimated useful life (Year)
Astero [Member] | Developed Technology Rights [Member]
Intangible assets		$ 2,840,000	$ 2,840,000
Intangible assets (Year)			9 years
Intangible assets, estimated useful life (Year)			9 years
Astero [Member] | Developed Technology Rights [Member] | Minimum [Member]
Intangible assets (Year)			5 years
Intangible assets, estimated useful life (Year)			5 years
Astero [Member] | In Process Research and Development [Member]
Intangible assets		$ 650,000	$ 650,000
SAVSU [Member]
Cash and cash equivalents								$ 1,251,000
Accounts receivable, net								753,000
Intangible assets							$ 12,200,000
Goodwill							19,500,000	21,037,000
Accounts Payable								(807,000)
Other liabilities								232,000
Fair value of net assets acquired							35,800,000	35,850,000
Prepaid expenses and other current assets								19,000
Property, plant and equipment, net								546,000
Operating right-of-use asset							232,000	233,000
Assets held for lease								2,441,000
Deferred tax liabilities								(1,541,000)
Other liabilities								(232,000)
Fair value of net assets acquired							$ 35,800,000	35,850,000
SAVSU [Member] | Customer Relationships [Member]
Intangible assets								80,000
SAVSU [Member] | Trade Names [Member]
Intangible assets								1,320,000
SAVSU [Member] | Developed Technology Rights [Member]
Intangible assets								$ 10,750,000
CBS Acquisition [Member]
Accounts receivable, net	$ 1,044,000
Inventory	3,232,000
Intangible assets					$ 6,800,000
Goodwill	3,085,000				$ 3,100,000
Accounts Payable	(1,328,000)
Other liabilities	611,000
Fair value of net assets acquired	15,856,000
Prepaid expenses and other current assets	29,000
Property, plant and equipment, net	3,615,000
Other liabilities	(611,000)
Fair value of net assets acquired	15,856,000
Inventory	3,232,000
Intangible assets, estimated fair value	6,790,000
CBS Acquisition [Member] | Customer Relationships [Member]
Intangible assets	$ 560,000
Intangible assets (Year)	6 years
Intangible assets, estimated fair value	$ 560,000
Intangible assets, estimated useful life (Year)	6 years
CBS Acquisition [Member] | Trade Names [Member]
Intangible assets	$ 800,000
Intangible assets (Year)	6 years
Intangible assets, estimated fair value	$ 800,000
Intangible assets, estimated useful life (Year)	6 years
CBS Acquisition [Member] | Developed Technology Rights [Member]
Intangible assets	$ 5,430,000
Intangible assets (Year)	9 years
Intangible assets, estimated fair value	$ 5,430,000
Intangible assets, estimated useful life (Year)	9 years