| Non-current defined benefit plan | 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 post-employment benefit plans other than defined contribution plans. | en | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |
| Report the value, as at the reporting date, the aggregate non-current portion of post-employment benefit plans other than defined contribution plans. | en | http://xbrl.ssm.com.my/role/ssm/rol_ssmt-mpers-cor_2017-12-31/ReportingDocumentation | http://www.xbrl.org/2003/role/link |