Note H - Investments (Details Textual)	12 Months Ended
Dec. 31, 2019 USD ($)	Dec. 31, 2019 HKD ($)	Dec. 31, 2018 USD ($)
Debt Securities, Held-to-maturity, Current	$ 512,821	$ 4,000,000
Investment in Held-to-maturity Debt Securities, Term (Year)	1 year
Investment in Held-to-maturity Debt Securities, Interest Rate	5.00%	5.00%
Limit of Bond		$ 20,000,000

Amount of investment in debt security measured at amortized cost (held-to-maturity), classified as current.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121553693&loc=d3e26626-111562

Name:	us-gaap_HeldToMaturitySecuritiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant