Name:	futu_IncomeTaxDisclosureLineItems
Namespace Prefix:	futu_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Represents the pre-tax deduction ratio for R&D expenses.

No definition available.

Name:	futu_PreTaxDeductionRatioForResearchAndDevelopmentExpenses
Namespace Prefix:	futu_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Percentage of preferential tax rate applicable to the company.

No definition available.

Name:	futu_PreferentialTaxRatePercentage
Namespace Prefix:	futu_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

The period during which the preferential tax rate is valid, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	futu_PreferentialTaxRateValidPeriod
Namespace Prefix:	futu_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

The percentage of reduced withholding tax rate applicable to beneficial owner.

No definition available.

Name:	futu_ReducedWithholdingTaxRate
Namespace Prefix:	futu_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Percentage of research and development expenses that can be claimed as super deduction by the company.

No definition available.

Name:	futu_SuperDeductionOfResearchAndDevelopmentExpensesPercentage
Namespace Prefix:	futu_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

The percentage of withholding tax rate.

No definition available.

Name:	futu_WithholdingTaxRate
Namespace Prefix:	futu_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-12

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 6.I.Fact.4)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-1

Name:	us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Name:	srt_StatementGeographicalAxis=country_US
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_StatementGeographicalAxis=country_HK
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_StatementScenarioAxis=futu_AssessableProfitsOnFirstHk2MillionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_StatementScenarioAxis=futu_AssessableProfitsInExcessOfHk2MillionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_StatementGeographicalAxis=country_CN
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_OwnershipAxis=futu_FutuNetworkTechnologyShenzhenCo.LtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: