Income Taxes - Narrative (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Operating Loss Carryforwards [Line Items]      
Valuation recorded $ 12,100    
Operating loss carryforwards 16,600    
Unrecognized tax benefits 4,240 $ 3,519 $ 2,320
Proficient [Member]      
Operating Loss Carryforwards [Line Items]      
Operating loss carryforwards $ 5,100