Segment Information - Revenue by Geographic Region (Table) (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Revenues From External Customers And Long Lived Assets [Line Items]      
Revenue by geographic region $ 517,739 $ 463,049 $ 419,782
North America      
Revenues From External Customers And Long Lived Assets [Line Items]      
Revenue by geographic region 4,248 5,513 6,218
Europe      
Revenues From External Customers And Long Lived Assets [Line Items]      
Revenue by geographic region 142,688 124,857 109,267
Asia      
Revenues From External Customers And Long Lived Assets [Line Items]      
Revenue by geographic region 135,614 91,552 73,073
South America      
Revenues From External Customers And Long Lived Assets [Line Items]      
Revenue by geographic region 208,751 212,616 220,336
Other      
Revenues From External Customers And Long Lived Assets [Line Items]      
Revenue by geographic region $ 26,438 $ 28,511 $ 10,888