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Operating costs and non-underlying items - Additional Information (Detail) - EUR (€) € in Millions | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Disclosure Of Gross Profit And Operating Costs [Abstract] |  |  |
Exchange gains/(losses) | € 45 | € 41 | € 49

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- Definition Disclosure of gross profit and operating costs [Abstract] + References No definition available. + Details
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- Definition Gain losses on exchange difference amounts on forward contracts and underlying transactions. + References No definition available. + Details
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