Note 5 - Leases (Details Textual)	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($) ft²	Mar. 31, 2020 USD ($)	Jun. 30, 2021 USD ($) ft²	Jun. 30, 2020 USD ($)
Operating Lease, Payments | $	$ 344,000	$ 421,000	$ 702,000	$ 900,000
HONG KONG
Area of Land (Square Foot)	7,300		7,300
Rolling Hills Estates [Member]
Area of Land (Square Foot)	4,900		4,900
Lessee, Operating Lease, Renewal Term (Year)	5 years		5 years
Richmond, British Columbia [Member]
Area of Land (Square Foot)	1,600		1,600
Metuchen, New Jersey [Member]
Area of Land (Square Foot)	2,000		2,000
CHINA
Lessee, Number of Branches	8		8