Share capital and additional paid-in capital (Details Textual) - 12 months ended Dec. 31, 2016	$ / shares	KYD / shares
Share Capital And Additional Paid In Capital [Line Items]
Options Redemption Price \| KYD / shares		KYD 0.01
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.
Class B Common Stock [Member]
Share Capital And Additional Paid In Capital [Line Items]
Options Exercise Price \| $ / shares	$ 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

Share Capital And Additional Paid In Capital [Line Items]

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.

Share Capital And Additional Paid In Capital [Line Items]

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

Option Expiration Date

Jul. 31, 2017