Share capital and additional paid-in capital (Details Textual)	12 Months Ended
Dec. 31, 2014 KYD	Dec. 31, 2014 Class B Common Stock [Member] USD ($)	Dec. 31, 2013 Class B Common Stock [Member]
Share Capital And Additional Paid In Capital [Line Items]
Options Redemption Price	0.01cwco_OptionsRedemptionPrice
Options Exercise Price		$ 100.00
Criteria One Description		a person or group of affiliated or associated persons (an Acquiring Person) has acquired, or obtained the right to acquire, beneficial ownership of 20% or more of the Companys outstanding common shares
Criteria Two Description		an Acquiring Person (or by certain related parties) following any person, alone or jointly with its affiliates and associates, becoming an Acquiring Person would entitle its holder to purchase $200.00 worth of the Companys common shares for $100.00.
Option Expiration Date			Jul. 31, 2017
Options, Exercise Basis Assumptions	Assuming that the common shares had a per share value of $20.00 at such time, the holder of each valid Option would be entitled to purchase 10 common shares for $100.00

an Acquiring Person (or by certain related parties) following any person, alone or jointly with its affiliates and associates, becoming an Acquiring Person would entitle its holder to purchase $200.00 worth of the Companys common shares for $100.00.

Options, Exercise Basis Assumptions

Assuming that the common shares had a per share value of $20.00 at such time, the holder of each valid Option would be entitled to purchase 10 common shares for $100.00