Goodwill and Intangible Assets (Amortization) (Details) - USD ($)
$ in Thousands
Sep. 30, 2017
Dec. 31, 2016
Amortization of finite-lived intangible assets    
2017 $ 1,315  
2018 5,075  
2019 4,959  
2020 4,053  
2021 2,196  
Thereafter 8,077  
Intangible assets, net $ 25,675 $ 23,120