Name:	jl_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipOwnershipInterests
Namespace Prefix:	jl_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Description of business purpose of the subsidiary of the limited liability company or limited partnership, for example, its day-to-day operating functions and whether it acts as a holding or operating company.

No definition available.

Name:	us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipBusinessPurpose
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Date the subsidiary of the limited liability company (LLC) or limited partnership (LP) was formed, in YYYY-MM-DD format.

No definition available.

Name:	us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The number of units or percentage investment held in the subsidiary by the limited liability company or limited partnership.

No definition available.

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

State in which the subsidiary of the limited liability company or limited partnership was organized.

No definition available.

Name:	us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipState
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Name:	srt_OwnershipAxis=jl_JLongGroupLimitedtheCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_OwnershipAxis=jl_StratumStarLimitedStratumStarMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_OwnershipAxis=jl_AlpineEagleLimitedAlpineEagleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_OwnershipAxis=jl_JLongLimitedJLHKMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_OwnershipAxis=jl_SunChoiceEnterprisesLimitedSunChoiceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: