XML 46 R36.htm IDEA: XBRL DOCUMENT v3.7.0.1
Income taxes (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Income Tax Disclosure [Abstract]        
Income tax (expense) benefit $ (1,452) $ 319 $ (1,144) $ 2,389