Note 13 - Acquisitions (Details Textual) - USD ($)				1 Months Ended	2 Months Ended	3 Months Ended			5 Months Ended	6 Months Ended	9 Months Ended		12 Months Ended
	Nov. 12, 2019	Aug. 08, 2019	Apr. 01, 2019	Nov. 30, 2019	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Nov. 11, 2019	Aug. 07, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018
Goodwill, Ending Balance					$ 33,637,000	$ 28,342,000	$ 9,515,000		$ 33,637,000	$ 9,515,000	$ 33,637,000	$ 28,342,000	$ 33,637,000
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable												19,932,000
Equity Method Investments						1,000,000	6,100,000	$ 6,317,000		6,100,000		1,000,000		6,548,000			$ 6,857,000	$ 1,900,000	$ 926,000
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain (Loss), Net, Total						10,108,000						10,108,000	10,108,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles								4,120,000
Business Combination, Acquisition Related Costs						291,000	$ 39,000	$ 208,000		$ 247,000		$ 538,000	$ 940,000
SAVSU [Member]
Equity Method Investments		$ 5,800,000
Astero [Member]
Business Acquisition, Percentage of Voting Interests Acquired					12.50%				12.50%		12.50%		12.50%
Payments to Acquire Businesses, Initial Cash Payment			$ 8,000,000
Payments to Acquire Businesses, Deferred Cash Payment			4,500,000
Business Combination, Consideration Transferred, Liabilities Incurred			1,491,000
Payments to Acquire Businesses, Gross			12,521,000
Business Combination, Contingent Consideration, Asset, Total			8,500,000
Business Combination, Contingent Consideration, Liability, Total			1,500,000
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			9,515,000
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, Consideration Transferred, Total			13,941,000
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
SAVSU [Member]
Business Acquisition, Percentage of Voting Interests Acquired		55.60%
Goodwill, Ending Balance		$ 19,500,000														$ 21,037,000
Business Combinations, Number of Shares Acquired (in shares)		8,616
Business Combinations, Number of Shares Acquired (in shares)		1,100,000	1,100,000
Share Price (in dollars per share)		$ 18.12
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable		$ 19,932,000											$ 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		12,200,000
Business Combination, Consideration Transferred, Including Equity Interest in Acquiree Held Prior to Combination, Total		$ 35,800,000
Business Combination, Acquisition Related Costs						$ 11,000,000
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)
CBS Acquisition [Member]
Business Combination, Consideration Transferred, Liabilities Incurred				$ 856,000
Payments to Acquire Businesses, Gross	$ 11,000,000			11,000,000
Business Combination, Contingent Consideration, Asset, Total	15,000,000
Goodwill, Ending Balance	3,100,000														$ 3,085,000
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	4,000,000			4,000									$ 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
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	6,800,000
Business Combination, Consideration Transferred, Total	15,000,000			$ 15,856,000
Business Combination, Cash Holdback Escrow to Satisfy Indemnification Claims	$ 550,000
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)