Intangible Assets Including Goodwill - Additional Information (Details) € in Millions |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2018
EUR (€)
Segment
|
Dec. 31, 2017
EUR (€)
|
Dec. 31, 2016
EUR (€)
|
|
| Intangible Assets And Goodwill [Abstract] | |||
| Amortization included in research and development | € | € 11 | € 8 | € 5 |
| Number of operating segments | Segment | 2 | ||