Note 11 - Acquisitions (Details Textual) - USD ($)						2 Months Ended	3 Months Ended		5 Months Ended	9 Months Ended	12 Months Ended
	Oct. 01, 2020	Sep. 30, 2020	Nov. 12, 2019	Aug. 08, 2019	Apr. 01, 2019	Dec. 31, 2019	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Nov. 11, 2019	Aug. 07, 2019	Mar. 31, 2019	Dec. 31, 2018
Payment for Contingent Consideration Liability, Financing Activities											$ 483,000	$ (0)
Business Combination, Contingent Consideration, Liability, Total							$ 221,000	$ 388,000			221,000
Goodwill, Ending Balance						$ 33,637,000	58,449,000		$ 33,637,000	$ 33,637,000	58,449,000	33,637,000				$ 0
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain (Loss), Net, Total											0	10,108,000
SAVSU [Member]
Equity Method Investments				$ 5,800,000
Astero [Member]
Payments to Acquire Businesses, Gross					$ 12,521,000
Payments to Acquire Businesses, Initial Cash Payment					8,000,000.0
Payments to Acquire Businesses, Deferred Cash Payment					4,500,000
Business Combination, Consideration Transferred, Liabilities Incurred					1,491,000
Payment for Contingent Consideration Liability, Financing Activities								$ 483,000
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High					8,500,000
Business Combination, Contingent Consideration, Liability, Total					1,500,000	1,100,000	81,000		1,100,000	1,100,000	81,000	1,100,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Tangible Assets					324,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets					4,100,000
Goodwill, Ending Balance					9,500,000										$ 9,515,000
Business Acquisition, Goodwill, Expected Tax Deductible Amount					1,100,000
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net, Total															$ 13,941,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles					4,120,000
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual										1,200,000
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual										(1,500,000)
Astero [Member] | Earnout Payments Payable in Each Calendar Years of 2019, 2020 and 2021 [Member]
Business Combination, Consideration Transferred, Liabilities Incurred					3,500,000
Astero [Member] | Earnout Payment for Calendar Year 2021 [Member]
Business Combination, Consideration Transferred, Liabilities Incurred					$ 5,000,000.0
SAVSU [Member]
Goodwill, Ending Balance				$ 19,500,000										$ 21,037,000
Business Combinations, Number of Shares Acquired (in shares)				8,616
Business Acquisition, Percentage of Voting Interests Acquired				56.00%
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares (in shares)				1,100,000
Share Price (in dollars per share)				$ 18.12
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable				$ 19,932,000							0	19,932,000
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net, Total				35,800,000										35,850,000
Business Combination, Step Acquisition, Equity Interest in Acquiree, Fair Value				$ 15,900,000
Business Combination, Step Acquisition, Equity Interest in Acquiree, Percentage				44.00%
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain (Loss), Net, Total				$ 10,100,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Tangible Assets, Net				4,200,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles				12,150,000
Business Combination, Consideration Transferred, Including Equity Interest in Acquiree Held Prior to Combination, Total				$ 35,800,000
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual									692,000
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual									(1,700,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities														$ 1,541,000
CBS Acquisition [Member]
Payments to Acquire Businesses, Gross			$ 11,000,000
Payments to Acquire Businesses, Initial Cash Payment			11,000,000.0
Business Combination, Consideration Transferred, Liabilities Incurred			856,000
Business Combination, Contingent Consideration, Liability, Total						856,000	140,000		$ 856,000	$ 856,000	140,000	856,000
Goodwill, Ending Balance			3,100,000										$ 2,954,000
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable			4,000,000.0								0	4,000,000
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net, Total													$ 15,856,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Tangible Assets, Net			6,000,000.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles			6,790,000
Business Combination, Consideration Transferred, Excluding Contingent Consideration			15,000,000.0
Business Combination, Cash Holdback Escrow to Satisfy Indemnification Claims			550,000
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable, Escrow Holdback			3,000,000.0
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual						2,100,000
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual						$ 187,000
CBS Acquisition [Member] | Earning Payments Payable in Each Calendar Year 2020, 2021, 2022, 2023, and 2024 [Member]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High			$ 15,000,000.0
SciSafe Holdings, Inc [Member]
Payments to Acquire Businesses, Gross	$ 15,000,000
Business Combination, Consideration Transferred, Liabilities Incurred	3,663,000
Business Combination, Contingent Consideration, Liability, Total	3,700,000						6,900,000				6,900,000
Goodwill, Ending Balance	$ 24,943,000
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares (in shares)	611,683
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	$ 17,916,000										$ 17,916,000	$ 0
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net, Total	$ 36,526,000
Business Combination, Step Acquisition, Equity Interest in Acquiree, Percentage	100.00%
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	$ 12,100,000
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual							1,800,000
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual							$ (416,000)
Business Acquisition, Share Price (in dollars per share)	$ 29.29
Business Acquisition, Amount Held in Escrow	$ 1,500,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Tangible Assets	2,800,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities	3,297,000
Payments to Acquire Notes Receivable		$ 500,000
Business Combination, Indemnification Assets, Amount as of Acquisition Date	$ 130,000
SciSafe Holdings, Inc [Member] | Maximum [Member]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares (in shares)	626,000