Note 5 - Debt (Details Textual) $ in Thousands		3 Months Ended		6 Months Ended
	Jan. 28, 2016 USD ($)	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)
Capital and Financing Lease Obligations Number of Leases		17		17		23
Interest Expense, Debt, Excluding Amortization		$ 500	$ 1,300	$ 1,100	$ 2,600
Interest Costs Capitalized		100	$ 100	100	$ 100
Letter of Credit [Member]
Letters of Credit Outstanding, Amount		1,000		1,000
The New Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 50,000
Line of Credit Facility, Dividend Restrictions, Maximum Amount	10,000
Long-term Line of Credit, Total		0		0		$ 5,700
Line of Credit Facility, Remaining Borrowing Capacity		$ 49,000		$ 49,000		$ 43,300
The New Credit Facility [Member] | Standby Letters of Credit [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 5,000