XML 65 R51.htm IDEA: XBRL DOCUMENT v3.8.0.1
Commitments (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Operating leases      
Rent expense $ 1,300 $ 900 $ 800
Future minimum payments required under the non-cancelable operating lease      
2018 1,379    
2019 1,421    
2020 721    
Total minimum lease payments $ 3,521