Note 16 - Risks and Uncertainties (Details Textual) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Sep. 30, 2022 USD ($) $ / bbl
Revenue from Contract with Customer, Excluding Assessed Tax	$ 31,370	$ 24,700	$ 62,479	$ 42,691
Oil and Gas, Average Sale Price (in USD per Barrel of Oil) | $ / bbl					70
Geospace Technologies Eurasia LLC (GTE) [Member]
Imported Product for Resale			2,300		$ 1,900
Equity, Attributable to Noncontrolling Interest	6,000		6,000
Cash	$ 3,200		3,200
Geospace Technologies Eurasia LLC (GTE) [Member] | Geographic Distribution, Domestic [Member]
Revenue from Contract with Customer, Excluding Assessed Tax			1,300		$ 1,900
Customer Concentration Risk [Member] | Accounts Receivable [Member]
Number of Major Customers	3
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Customer One [Member]
Accounts and Financing Receivable, after Allowance for Credit Loss	$ 8,500		8,500
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Customer Two [Member]
Accounts and Financing Receivable, after Allowance for Credit Loss	4,900		4,900
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Customer Three [Member]
Accounts and Financing Receivable, after Allowance for Credit Loss	$ 3,400		$ 3,400
Customer Concentration Risk [Member] | Revenue from Contract with Customer Benchmark [Member]
Number of Major Customers	3		3
Customer Concentration Risk [Member] | Revenue from Contract with Customer Benchmark [Member] | Customer One [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 9,900		$ 17,900
Customer Concentration Risk [Member] | Revenue from Contract with Customer Benchmark [Member] | Customer Two [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	2,900		5,600
Customer Concentration Risk [Member] | Revenue from Contract with Customer Benchmark [Member] | Customer Three [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 1,200		$ 2,900