v3.10.0.1
Clients and other receivable (Details) - USD ($)
$ in Thousands
Jun. 30, 2018
Dec. 31, 2017
Clients and other receivables [Abstract]    
Trade receivables $ 204,223 $ 186,728
Tax receivables 29,685 39,607
Prepayments 12,927 6,375
Other accounts receivable 13,406 11,739
Total $ 260,241 $ 244,449