Revenue Recognition (Details) $ in Millions  | 
9 Months Ended | 
|---|---|
| 
 Sep. 30, 2017  
USD ($)  
item 
 | |
| Revenue Recognition | |
| Number of criteria | item | 4 | 
| Additional cost to obtain technical support directly from the software publisher and upgrade to latest technology | $ | $ 0 | 
| X | ||||||||||
- References No definition available. 
  | 
| X | ||||||||||
- Definition Represents the additional cost charged by software publisher to obtain technical support and upgrade to the latest technology. No definition available. 
  | 
| X | ||||||||||
- Definition Represents the number of criteria to be fulfilled for recognition of revenue of software and hardware products and maintenance agreement sales. No definition available. 
  |