v3.7.0.1
Cash and cash equivalents (Details) - USD ($)
$ in Thousands
Mar. 31, 2017
Dec. 31, 2016
Mar. 31, 2016
Dec. 31, 2015
Cash and cash equivalents:        
Cash $ 16,737 $ 17,246    
Money market accounts 2,241 2,239    
Total cash and cash equivalents $ 18,978 $ 19,485 $ 14,651 $ 14,718