| Non-current employment termination benefits | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Report the value, as at the reporting date, the aggregate non-current portion of termination benefits which are employee benefits payable as a result of either | en | http://xbrl.ssm.com.my/role/ssm/rol_ssmt-mpers-cor_2017-12-31/ReportingDocumentation | http://www.xbrl.org/2003/role/link |
| Report the value, as at the reporting date, the aggregate non-current portion of termination benefits which are employee benefits payable as a result of either | en | http://xbrl.ssm.com.my/role/ssm/fs/mpers/lab_rol_ssmt-fs-mpers_2017-12-31/ReportingDocumentation | http://www.xbrl.org/2003/role/link |
| Employment termination benefits | en | http://xbrl.ssm.com.my/role/ssm/fs/mpers/lab_rol_ssmt-fs-mpers_2017-12-31/ReportingLabel | http://www.xbrl.org/2003/role/link |