Income Tax - Additional Information (Details) - EUR (€) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Disclosure Of Income Tax [Line Items] | |||
| Income tax relating to components of other comprehensive income | € 147,000,000 | € 0 | € 0 |
| Uncertain tax position liability, expected to be resolved | 1,000,000 | ||
| Deferred tax on foreign exchange differences | 8,000,000 | € 0 | € 0 |
| Deferred tax liability recognized on investment in subsidiaries | € 0 | ||
| Luxembourg | |||
| Disclosure Of Income Tax [Line Items] | |||
| Statutory tax rate | 26.01% | 27.08% | 29.22% |
| Provisions | |||
| Disclosure Of Income Tax [Line Items] | |||
| Current income tax expense on uncertain tax positions | € 1,000,000 | ||
| Uncertain tax position liability | € 2,000,000 | ||