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Borrowings - Summary of Composition of Carrying Amounts of Total Borrowings (Detail) - EUR (€) € in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of detailed information about borrowings [line items]
Total borrowings	€ 2,127	€ 2,468	€ 2,233
U.S. Dollar [member]
Disclosure of detailed information about borrowings [line items]
Total borrowings	1,387	1,887
Euro [member]
Disclosure of detailed information about borrowings [line items]
Total borrowings	720	575
Other currencies [member]
Disclosure of detailed information about borrowings [line items]
Total borrowings	€ 20	€ 6

X

- Definition

The amount of outstanding funds that the entity is obligated to repay.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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+ Details

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- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

+ References

No definition available.

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