Note 11 - Notes Payable and Long-term Debt - Schedule of Notes Payable and Long-term Debt (Details) (Parentheticals) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 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	3.40%	3.40%
Long-term debt, maturity date	Nov. 30, 2021	Nov. 30, 2021
Chailease Finance Co, Ltd. [Member] | Promissory Note 2 [Member]
Long-term debt, interest	3.10%	3.10%
Long-term debt, 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%
Long-term debt, maturity date	Apr. 11, 2020	Apr. 11, 2020
SPD Bank [Member] | Revolving Credit Facility [Member]
Long-term debt, maximum	$ 25,449,000	$ 25,449,000
Long-term debt, interest	4.57%	4.57%
Long-term debt, maturity date	May 24, 2024	May 24, 2024
China Zheshang Bank Co., Ltd [Member] | Revolving Credit Facility [Member]
Long-term debt, maximum	$ 7,167,000	$ 7,167,000
Long-term debt, interest	5.70%	5.70%
Long-term debt, maturity date	Jun. 20, 2022	Jun. 20, 2022
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%
Long-term debt, maturity date	Apr. 02, 2021	Apr. 02, 2021
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%
Long-term debt, maturity date	Jul. 31, 2020	Jul. 31, 2020