Land use right net (Details) - ZHEJIANG TIANLAN - CNY (¥) ¥ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Land use right, gross	¥ 7,361	¥ 7,361
Less: accumulated amortization	2,662	2,511
Land use right, net	¥ 4,699	¥ 4,850

Gross carrying amount before accumulated amortization as of the balance sheet date of an intangible asset that arises from a contractual arrangement with a third party (not including franchise rights and license agreements).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482665/350-30-50-2

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