Note 13 - Short-term Bank Loan and Credit Facility (Details Textual) ¥ in Millions						12 Months Ended
		Sep. 29, 2019 USD ($)	Sep. 29, 2019 CNY (¥)	Jul. 29, 2019 USD ($)	Jul. 29, 2019 CNY (¥)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2018 CNY (¥)	Sep. 30, 2018 USD ($)	Dec. 31, 2017 CNY (¥)
Short-term Bank Loans and Notes Payable	[1]					$ 874,000	$ 765,000
Restricted Cash and Cash Equivalents, Total						$ 25,500
Minimum [Member]
Short-term Debt, Weighted Average Interest Rate, at Point in Time						5.22%	5.22%	5.22%		5.22%
Debt Instrument, Basis Spread on Variable Rate						20.00%	20.00%
Maximum [Member]
Short-term Debt, Weighted Average Interest Rate, at Point in Time						5.655%	5.655%	5.655%		5.655%
Debt Instrument, Basis Spread on Variable Rate						30.00%	30.00%
VIEs [Member]
Short-term Bank Loans and Notes Payable						$ 874,000	$ 765,000
VIEs [Member] | Loans Payable [Member]
Short-term Bank Loans and Notes Payable						700,000		¥ 5.0
VIEs [Member] | Loan Payable Borrowed on August 16, 2017 [Member]
Short-term Bank Loans and Notes Payable						$ 440,000		3.0
VIEs [Member] | Loan Payable Borrowed on September 30, 2018 [Member]
Short-term Bank Loans and Notes Payable								¥ 3.0	$ 440,000
VIEs [Member] | Loan Payable Borrowed on September 30, 2018 [Member] | Scenario, Forecast [Member]
Repayments of Short-term Debt, Total		$ 220,000	¥ 1.5	$ 220,000	¥ 1.5
VIEs [Member] | Loan Payable Maturing on August 15, 2018 [Member]
Short-term Bank Loans and Notes Payable							500,000			¥ 3.0
VIEs [Member] | Loan Payable Maturing on October 18, 2017 [Member]
Short-term Bank Loans and Notes Payable							$ 300,000			¥ 2.0

[1] All of the VIEs' assets can be used to settle obligations of their primary beneficiary. Liabilities recognized as a result of consolidating these VIEs do not represent additional claims on the Company's general assets (Note 2).