RELATED PARTY BALANCES AND TRANSACTION - Additional Information (Details) - HKD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Payables to clients
Related Party Transaction [Line Items]
Payable to related parties	$ 19,553	$ 308,073
Directors and officers and their spouses \| Brokerage Services and Margin Loans
Related Party Transaction [Line Items]
Revenues earned	$ 2,211	$ 6,797	$ 3,040

Amount for accounts payable to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(a))
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant