Significant Customers and Geographic Information (Details 2) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Net revenue by geographic information    
Revenue $ 169.4 $ 156.5
U.S.    
Net revenue by geographic information    
Revenue 127.9 111.6
International    
Net revenue by geographic information    
Revenue $ 41.5 $ 44.9