Amount of allowance for credit loss on accounts receivable.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=123577603&loc=d3e5074-111524

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
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-URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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-Subparagraph (SX 210.5-02(4))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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

Accounts receivable net (Details) ¥ in Thousands, $ in Thousands	Dec. 31, 2022 USD ($)	Dec. 31, 2022 CNY (¥)	Dec. 31, 2021 USD ($)	Dec. 31, 2021 CNY (¥)	Dec. 31, 2020 USD ($)	Dec. 31, 2020 CNY (¥)
Contract receivables \| $	$ 1,614		$ 3,661
Less: allowance for doubtful accounts \| $	(28)		(30)		$ (30)
Accounts receivable, net \| $	$ 1,586		$ 3,631
ZHEJIANG TIANLAN
Contract receivables \| ¥		¥ 175,792		¥ 148,889
Less: allowance for doubtful accounts \| ¥		(40,019)		(42,867)		¥ (42,182)
Accounts receivable, net \| ¥		¥ 135,773		¥ 106,022