| Credit derivative, fair value | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Credit derivative, fair value at beginning of period | en | http://www.xbrl.org/2003/role/periodStartLabel | http://www.xbrl.org/2003/role/link |
| Credit derivative, fair value at end of period | en | http://www.xbrl.org/2003/role/periodEndLabel | http://www.xbrl.org/2003/role/link |
| The fair value of a credit derivative. [Refer: At fair value [member]; Derivatives [member]] | en | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |
| Derivati su crediti, fair value (valore equo) | it | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Il fair value (valore equo) di un derivato su crediti. [Rif: Al fair value (valore equo) [member]; Derivati [member]] | it | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |
| Derivati su crediti, fair value (valore equo) all'inizio del periodo | it | http://www.xbrl.org/2003/role/periodStartLabel | http://www.xbrl.org/2003/role/link |
| Derivati su crediti, fair value (valore equo) alla fine del periodo | it | http://www.xbrl.org/2003/role/periodEndLabel | http://www.xbrl.org/2003/role/link |