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BORROWINGS - Movement in Borrowings (Details) - EUR (€) € in Millions |  |  | 6 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Jun. 30, 2020 | Aug. 08, 2019 | Jun. 30, 2020 | Jun. 30, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Disclosure of detailed information about borrowings [line items] |  |  |  |  |  |  |
Beginning Balance |  |  | € 2,361 |  | € 2,361 |  |
Cash flows |  |  |  |  |  |  |
Proceeds from issuance of Senior Notes |  |  |  | € 0 | 290 | € 0 | € 0
Repayments of Senior Notes |  |  |  |  | (200) | (100) | 0
Repayments of U.S. revolving credit facility |  |  |  |  | (129) |  |
Proceeds from U.S. revolving credit facility |  |  |  |  |  | 105 |
Proceeds from other borrowings |  |  |  |  | 202 | 8 | 0
Repayments from other borrowings |  |  |  |  | (10) | (4) | (1)
Lease repayments |  |  |  |  | (35) | (86) |
Payment of deferred financing costs |  |  |  |  | (6) | 0 |
Non-cash changes |  |  |  |  |  |  |
Borrowings assumed through business combination |  |  |  |  | 0 | 75 |
Movement in interests accrued or capitalized |  |  |  |  | (1) | 1 |
Changes in leases and other loans |  |  |  |  | 62 | 75 |
Deferred arrangement fees |  |  |  |  | 5 | 5 |
Effects of changes in foreign exchange rates |  |  |  |  | (148) | 29 |
Ending Balance |  |  |  |  | 2,391 | 2,361 |
Borrowings |  |  | 2,361 |  | 2,361 | 2,361 |
Senior Unsecured Notes due 2021 |  |  |  |  |  |  |
Disclosure of detailed information about borrowings [line items] |  |  |  |  |  |  |
Beginning Balance |  |  | € 200 |  | 200 |  |
Cash flows |  |  |  |  |  |  |
Repayments of Senior Notes | € (200) | € (100) |  |  |  |  |
Non-cash changes |  |  |  |  |  |  |
Ending Balance |  | 300 |  |  | € 0 | 200 |
Nominal rate |  |  | 4.625% |  | 4.625% |  |
Borrowings |  | € 300 | € 200 |  | € 200 | 200 |
Previously stated |  |  |  |  |  |  |
Disclosure of detailed information about borrowings [line items] |  |  |  |  |  |  |
Beginning Balance |  |  |  | 2,151 |  | 2,151 |
Non-cash changes |  |  |  |  |  |  |
Ending Balance |  |  |  |  |  |  | 2,151
Borrowings |  |  |  | 2,151 |  | 2,151 | 2,151
IFRS 16 application | IFRS 16 |  |  |  |  |  |  |
Disclosure of detailed information about borrowings [line items] |  |  |  |  |  |  |
Beginning Balance |  |  |  | 102 |  | 102 |
Non-cash changes |  |  |  |  |  |  |
Ending Balance |  |  |  |  |  |  | 102
Borrowings |  |  |  | 102 |  | 102 | 102
Restated |  |  |  |  |  |  |
Disclosure of detailed information about borrowings [line items] |  |  |  |  |  |  |
Beginning Balance |  |  |  | 2,253 |  | 2,253 |
Non-cash changes |  |  |  |  |  |  |
Ending Balance |  |  |  |  |  |  | 2,253
Borrowings |  |  |  | € 2,253 |  | € 2,253 | € 2,253

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