Business Segments - Summary of Revenue by Geographic Region (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Revenues From External Customers And Long Lived Assets [Line Items]        
Total revenue $ 28,059 $ 28,505 $ 79,463 $ 91,483
Domestic        
Revenues From External Customers And Long Lived Assets [Line Items]        
Total revenue 22,708 24,621 64,214 79,054
International        
Revenues From External Customers And Long Lived Assets [Line Items]        
Total revenue $ 5,351 $ 3,884 $ 15,249 $ 12,429