Revenue (Details)  | 
3 Months Ended | 
|---|---|
Mar. 31, 2019  | |
| Revenue [Abstract] | |
| Number of principal reporting segments | 4 | 
| X | ||||||||||
- Definition The number of reporting segments for an entity. No definition available. 
  | 
| X | ||||||||||
- Definition Revenue [Abstract] No definition available. 
  |