v3.8.0.1
Intangible Assets - Estimated Future Amortization Expense (Details) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]    
2018 $ 8,032  
2019 6,259  
2020 2,482  
2021 437  
Net book value $ 17,210 $ 6,437