Intangible Assets - Schedule of Amortization Expense (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]      
Total amortization $ 4,134 $ 4,251 $ 4,405
Acquired technology and domain name      
Finite-Lived Intangible Assets [Line Items]      
Total amortization 3,047 3,164 3,318
Customer relationships      
Finite-Lived Intangible Assets [Line Items]      
Total amortization 760 760 760
Trade names      
Finite-Lived Intangible Assets [Line Items]      
Total amortization $ 327 $ 327 $ 327