| Investments in subsidiaries, joint ventures and associates | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Total investments in subsidiaries, joint ventures and associates | en | http://www.xbrl.org/2003/role/totalLabel | http://www.xbrl.org/2003/role/link |
| The amount of investments in subsidiaries, joint ventures and associates in an entity's separate financial statements. [Refer: Associates [member]; Joint ventures [member]; Subsidiaries [member]; Investments in subsidiaries] | en | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |
| Partecipazioni in controllate, in joint venture e in società collegate | it | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| L'ammontare delle partecipazioni in controllate, in joint venture e in società collegate nel bilancio separato dell'entità. [Rif: Società collegate [member]; Joint venture [member]; Controllate [member]; Partecipazioni in società controllate] | it | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |