Contingencies (Details) $ in Millions	3 Months Ended
Mar. 31, 2021 USD ($) segment	Mar. 31, 2020	Dec. 31, 2020 USD ($)
Contingencies
Number of reporting units \| segment	4
Cayman Water Retail Operations, Percentage Of Revenue	33.00%	35.00%
Cayman Water Retail Operations, Percentage Of Gross Profit	49.00%	51.00%
WSC [Member]
Contingencies
Accounts Receivable, Net \| $	$ 19.5		$ 16.8

Represents the percentage of consolidated gross profit from Cayman Water retail operations.

No definition available.

Name:	cwco_CaymanWaterRetailOperationsPercentageOfGrossProfit
Namespace Prefix:	cwco_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of consolidated revenue from Cayman Water retail operations.

+ References

No definition available.

+ Details

Name:	cwco_CaymanWaterRetailOperationsPercentageOfRevenue
Namespace Prefix:	cwco_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

+ References

No definition available.

+ Details

Name:	cwco_CommitmentsAndContingenciesLineItems
Namespace Prefix:	cwco_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(5))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

+ Details

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

- Definition

Number of reporting units tested for impairment of goodwill. A reporting unit is an operating segment or one level below an operating segment.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfReportingUnits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_MajorCustomersAxis=cwco_WSCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: