Lease obligations (Details 3)	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Weighted-average remaining lease term - operating leases	23 months	16 months
Weighted-average discount rate - operating leases	5.00%	5.00%
ZHEJIANG TIANLAN
Weighted-average remaining lease term - finance leases	0 months	0 months
Weighted-average discount rate - finance leases	5.90%	5.90%

Weighted average discount rate for operating lease calculated at point in time.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (g)(4)
-URI https://asc.fasb.org/extlink&oid=128292326&loc=SL77918686-209980

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 55
-Paragraph 53
-URI https://asc.fasb.org/extlink&oid=123414884&loc=SL77918982-209971

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant