v2.4.1.9
Employee pension (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Employee pension [Abstract]      
Pension expense $ 73us-gaap_PensionExpense $ 135us-gaap_PensionExpense $ 74us-gaap_PensionExpense