Note 5 - Financing Arrangements (Details Textual) ¥ in Billions		12 Months Ended
	Apr. 15, 2020 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2021 CNY (¥)	Jun. 15, 2017 USD ($)
Debt Issuance Costs, Net, Total			$ 79,000
Proceeds from Issuance of Long-term Debt, Total		$ 0	6,077,000
Long-term Debt, Total			7,069,000
Gain (Loss) on Extinguishment of Debt, Total		6,171,000	0
Paycheck Protection Program CARES Act [Member]
Proceeds from Issuance of Long-term Debt, Total	$ 6,077,000
Long-term Debt, Total		6,077,000
Interest Payable		93,000
Gain (Loss) on Extinguishment of Debt, Total		6,170,000
Bank of America [Member] | Credit Agreement [Member]
Long-term Line of Credit, Total		9,016,000	3,328,000
Debt Issuance Costs, Net, Total		$ 58,000
Line of Credit, Minimum Fixed Charge Coverage Ratio During the Period		1.0
Line of Credit Facility, Remaining Borrowing Capacity		$ 3,539,000	$ 8,131,000
Bank of America [Member] | Credit Agreement [Member] | Line of Credit [Member]
Line of Credit Facility, Maximum Borrowing Capacity					$ 16,000,000
Debt Instrument, Interest Rate During Period		3.50%	4.00%
China Construction Bank [Member] | Line of Credit [Member]
Line of Credit Facility, Maximum Borrowing Capacity		$ 1,600		¥ 10
Long-term Line of Credit, Total		$ 0	$ 0
Debt Instrument, Interest Rate, Stated Percentage		4.50%		4.50%