Foreign exchange rate used to translate amounts denominated in functional currency to reporting currency.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479424/830-30-S99-1

+ Details

Name:	us-gaap_ForeignCurrencyExchangeRateTranslation1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

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.

+ References

No definition available.

+ Details

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

- Definition

Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (a)
-SubTopic 10
-Topic 606
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-13

+ Details

Name:	us-gaap_RevenueRemainingPerformanceObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

+ References

No definition available.

+ Details

Name:	us-gaap_SaleOfStockPricePerShare
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	srt_ProductOrServiceAxis=JLHL_EngineeringSolutionServiceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=JLHL_SystemMaintenanceRevenueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Recent accounting pronouncements (Details Narrative)	Mar. 31, 2026 $ / shares	Mar. 31, 2026 CNY (¥)	Mar. 31, 2025 CNY (¥)
Product Information [Line Items]
Sale of Stock, Price Per Share \| $ / shares	$ 1.00
Foreign currency exchange rate, translation		6.8980
Revenue, Remaining Performance Obligation, Amount		¥ 36,541,289	¥ 18,048,402
Engineering Solution Service [Member]
Product Information [Line Items]
Revenue, Remaining Performance Obligation, Amount		33,262,734
System Maintenance Revenue [Member]
Product Information [Line Items]
Revenue, Remaining Performance Obligation, Amount		¥ 13,523,072