Intangible Assets - Future amortization (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Projected Amortization Expense [Abstract]    
2017 $ 2,208  
2018 2,208  
2019 1,182  
2020 1,182  
Total $ 6,780 $ 8,988