Revenue and Expenses - Revenues (Details) - EUR (€) € in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Analysis of income and expense [abstract]
Rendering of services	€ 47,175	€ 47,321	€ 49,681
Net sales	4,833	4,715	5,235
Total	€ 52,008	€ 52,036	€ 54,916

The income arising in the course of an entity's ordinary activities. Income is increases in economic benefits during the accounting period in the form of inflows or enhancements of assets or decreases of liabilities that result in an increase in equity, other than those relating to contributions from equity participants.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2017-01-01
-Paragraph 28
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=8&date=2017-03-01&anchor=para_28_a&doctype=Standard
-URIDate 2017-03-09

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2017-01-01
-Paragraph 23
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=8&date=2017-03-01&anchor=para_23_a&doctype=Standard
-URIDate 2017-03-09

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2017-01-01
-Paragraph 32
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=8&date=2017-03-01&anchor=para_32&doctype=Standard
-URIDate 2017-03-09

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2017-01-01
-Paragraph 33
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=8&date=2017-03-01&anchor=para_33_a&doctype=Standard
-URIDate 2017-03-09

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2017-01-01
-Paragraph 34
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=8&date=2017-03-01&anchor=para_34&doctype=Standard
-URIDate 2017-03-09

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2017-01-01
-Paragraph 82
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_82_a&doctype=Standard
-URIDate 2017-03-09

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 1
-IssueDate 2017-01-01
-Paragraph 103
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_103&doctype=Standard
-URIDate 2017-03-09

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2018-01-01
-Name IAS
-Number 18
-IssueDate 2017-01-01
-Paragraph 35
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=18&date=2017-03-02&anchor=para_35_b&doctype=Standard&book=B
-URIDate 2017-03-09

Reference 9: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 1
-IssueDate 2017-01-01
-Paragraph 102
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_102&doctype=Standard
-URIDate 2017-03-09

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2017-01-01
-Paragraph B12
-Subparagraph b
-Clause v
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=12&date=2017-03-01&anchor=para_B12_b_v&doctype=Appendix&seq=2
-URIDate 2017-03-09

Reference 11: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 12
-IssueDate 2017-01-01
-Paragraph B10
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=12&date=2017-03-01&anchor=para_B10_b&doctype=Appendix&seq=2
-URIDate 2017-03-09

+ Details