v3.5.0.2
Income taxes (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2016
Jun. 30, 2015
Jun. 30, 2016
Jun. 30, 2015
Dec. 31, 2015
Income taxes          
Income tax expense $ 124 $ 82 $ 362 $ 286  
Effective tax rate (as a percent) 1.70% 1.40% 2.20% 2.10%  
Uncertain tax positions $ 371   $ 371   $ 363
Uncertain tax positions, reduction to deferred tax assets 84   84   84
Accrued interest, net of federal income tax benefits, and penalties 58   58   $ 50
Unrecognized tax benefits that would affect the effective tax rate $ 229   $ 229