Income Tax - Summary of Reconciliation of Net Deferred Tax (Details) - EUR (€) € in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Reconciliation Of Changes In Deferred Tax Liability Asset [Abstract] | |||
| At January 1 | € 6 | € 6 | € 3 |
| Movement recognized in consolidated statement of operations | (11) | 136 | 5 |
| Movement recognized in consolidated statement of changes in equity and other comprehensive income | 18 | (136) | 2 |
| Movement due to acquisition | (6) | 0 | (4) |
| At December 31 | € 7 | € 6 | € 6 |