Note 11 - Notes Payable and Long-term Debt - Schedule of Notes Payable and Long-term Debt (Details) (Parentheticals) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Mar. 05, 2019	Mar. 30, 2018	Sep. 28, 2017
Chailease Finance Co, Ltd. [Member] | Promissory Note [Member]
Long-term debt, interest	3.50%	3.50%
Debt Instrument, Maturity Date	Jan. 21, 2022	Jan. 21, 2022
Chailease Finance Co, Ltd. [Member] | Promissory Note 2 [Member]
Long-term debt, interest	3.10%	3.10%
Debt Instrument, Maturity Date	Jan. 21, 2022	Jan. 21, 2022
Branch Banking and Trust Company [Member] | Revolving Credit Facility [Member]
Long-term debt, maximum			$ 20,000,000	$ 25,000,000	$ 60,000,000	$ 50,000,000
Far Eastern [Member] | Revolving Credit Facility [Member]
Long-term debt, maximum	$ 2,668,000	$ 2,668,000
Long-term debt, interest	1.70%	1.70%
Debt Instrument, Maturity Date	Apr. 11, 2020	Apr. 11, 2020
China Merchants Bank Co, Ltd [Member] | Revolving Credit Facility [Member]
Long-term debt, maximum	$ 8,917,000	$ 8,917,000
Long-term debt, interest	4.50%	4.50%
Debt Instrument, Maturity Date	Oct. 14, 2020	Oct. 14, 2020
SPD Bank [Member] | Revolving Credit Facility [Member]
Long-term debt, maximum	$ 25,449	$ 25,449
Debt Instrument, Maturity Date	May 24, 2024	May 24, 2024
SPD Bank [Member] | Revolving Credit Facility [Member] | Minimum [Member]
Long-term debt, interest	3.01%	3.01%
SPD Bank [Member] | Revolving Credit Facility [Member] | Maximum [Member]
Long-term debt, interest	4.57%	4.57%
Third Amendment to Loan Agreement with BB and T [Member] | Branch Banking and Trust Company [Member] | Revolving Credit Facility [Member]
Long-term debt, maximum	$ 20,000,000	$ 20,000,000
Long-term debt, interest	1.50%	1.50%
Debt Instrument, Maturity Date	Apr. 02, 2021	Apr. 02, 2021
Paycheck Protection Program, CARES Act [Member]
Long-term debt, interest	1.00%	1.00%
Debt Instrument, Maturity Date	Apr. 16, 2022	Apr. 16, 2022
Credit Facility [Member] | Taishin International Bank [Member] | Revolving Credit Facility [Member]
Long-term debt, maximum	$ 3,336,000	$ 3,336,000
Long-term debt, interest	2.20%	2.20%
Debt Instrument, Maturity Date	Oct. 16, 2020	Oct. 16, 2020
The ¥100M Credit Facility [Member] | China Zheshang Bank Co., Ltd [Member] | Revolving Credit Facility [Member]
Long-term debt, maximum	$ 14,125,000	$ 14,125,000
Long-term debt, interest	3.50%	3.50%
Debt Instrument, Maturity Date	Nov. 07, 2020	Nov. 07, 2020
The ¥50M Credit Facility [Member] | China Zheshang Bank Co., Ltd [Member] | Revolving Credit Facility [Member]
Long-term debt, maximum	$ 7,167	$ 7,167
Long-term debt, interest	5.70%	5.70%
Debt Instrument, Maturity Date	Jun. 20, 2022	Jun. 20, 2022