| r0.c0 | Shareholding Structure/Ordinary shares | | | | N/A | ssmt:OrdinarySharesMember |
| r0.c1 | Shareholding Structure/Preference shares | | | | N/A | ssmt:PreferenceSharesMember |
| r0.c2 | Shareholding Structure/Other kinds of shares | | | | N/A | ssmt:OtherKindsOfSharesMember |
| r0.c3 | Shareholding Structure/Total | | | | N/A | ssmt:SharesMember |
| r1.c0 | Summary of shareholding structure/Ordinary shares | | | | N/A | ssmt:OrdinarySharesMember |
| r1.c1 | Summary of shareholding structure/Preference shares | | | | N/A | ssmt:PreferenceSharesMember |
| r1.c2 | Summary of shareholding structure/Other kinds of shares | | | | N/A | ssmt:OtherKindsOfSharesMember |
| r1.c3 | Summary of shareholding structure/Total | | | | N/A | ssmt:SharesMember |
| r2.c0 | Number of shares subject to payments wholly in cash/Ordinary shares | ssmt:NumberOfSharesSubjectToPaymentsWhollyInCash | xbrli:sharesItemType | instant | xbrli:shares | ssmt:OrdinarySharesMember |
| r2.c1 | Number of shares subject to payments wholly in cash/Preference shares | ssmt:NumberOfSharesSubjectToPaymentsWhollyInCash | xbrli:sharesItemType | instant | xbrli:shares | ssmt:PreferenceSharesMember |
| r2.c2 | Number of shares subject to payments wholly in cash/Other kinds of shares | ssmt:NumberOfSharesSubjectToPaymentsWhollyInCash | xbrli:sharesItemType | instant | xbrli:shares | ssmt:OtherKindsOfSharesMember |
| r2.c3 | Number of shares subject to payments wholly in cash/Total | ssmt:NumberOfSharesSubjectToPaymentsWhollyInCash | xbrli:sharesItemType | instant | xbrli:shares | ssmt:SharesMember |
| r3.c0 | Number of shares subject to payment otherwise than cash/Ordinary shares | ssmt:NumberOfSharesSubjectToPaymentOtherwiseThanCash | xbrli:sharesItemType | instant | xbrli:shares | ssmt:OrdinarySharesMember |
| r3.c1 | Number of shares subject to payment otherwise than cash/Preference shares | ssmt:NumberOfSharesSubjectToPaymentOtherwiseThanCash | xbrli:sharesItemType | instant | xbrli:shares | ssmt:PreferenceSharesMember |
| r3.c2 | Number of shares subject to payment otherwise than cash/Other kinds of shares | ssmt:NumberOfSharesSubjectToPaymentOtherwiseThanCash | xbrli:sharesItemType | instant | xbrli:shares | ssmt:OtherKindsOfSharesMember |
| r3.c3 | Number of shares subject to payment otherwise than cash/Total | ssmt:NumberOfSharesSubjectToPaymentOtherwiseThanCash | xbrli:sharesItemType | instant | xbrli:shares | ssmt:SharesMember |
| r4.c0 | Total number of shares issued/Ordinary shares | ssmt:NumberOfSharesIssued | xbrli:sharesItemType | instant | xbrli:shares | ssmt:OrdinarySharesMember |
| r4.c1 | Total number of shares issued/Preference shares | ssmt:NumberOfSharesIssued | xbrli:sharesItemType | instant | xbrli:shares | ssmt:PreferenceSharesMember |
| r4.c2 | Total number of shares issued/Other kinds of shares | ssmt:NumberOfSharesIssued | xbrli:sharesItemType | instant | xbrli:shares | ssmt:OtherKindsOfSharesMember |
| r4.c3 | Total number of shares issued/Total | ssmt:NumberOfSharesIssued | xbrli:sharesItemType | instant | xbrli:shares | ssmt:SharesMember |
| r5.c0 | Other details on share capital/Ordinary shares | ssmt:OtherDetailsOnShareCapitalAbstract | xbrli:stringItemType | instant | N/A | ssmt:OrdinarySharesMember |
| r5.c1 | Other details on share capital/Preference shares | ssmt:OtherDetailsOnShareCapitalAbstract | xbrli:stringItemType | instant | N/A | ssmt:PreferenceSharesMember |
| r5.c2 | Other details on share capital/Other kinds of shares | ssmt:OtherDetailsOnShareCapitalAbstract | xbrli:stringItemType | instant | N/A | ssmt:OtherKindsOfSharesMember |
| r5.c3 | Other details on share capital/Total | ssmt:OtherDetailsOnShareCapitalAbstract | xbrli:stringItemType | instant | N/A | ssmt:SharesMember |
| r6.c0 | Total number of shares forfeited/Ordinary shares | ssmt:NumberOfSharesForfeited | xbrli:sharesItemType | instant | xbrli:shares | ssmt:OrdinarySharesMember |
| r6.c1 | Total number of shares forfeited/Preference shares | ssmt:NumberOfSharesForfeited | xbrli:sharesItemType | instant | xbrli:shares | ssmt:PreferenceSharesMember |
| r6.c2 | Total number of shares forfeited/Other kinds of shares | ssmt:NumberOfSharesForfeited | xbrli:sharesItemType | instant | xbrli:shares | ssmt:OtherKindsOfSharesMember |
| r6.c3 | Total number of shares forfeited/Total | ssmt:NumberOfSharesForfeited | xbrli:sharesItemType | instant | xbrli:shares | ssmt:SharesMember |
| r7.c0 | Total number of shares held as treasury shares/Ordinary shares | ssmt:NumberOfSharesHeldAsTreasuryShares | xbrli:sharesItemType | instant | xbrli:shares | ssmt:OrdinarySharesMember |
| r7.c1 | Total number of shares held as treasury shares/Preference shares | ssmt:NumberOfSharesHeldAsTreasuryShares | xbrli:sharesItemType | instant | xbrli:shares | ssmt:PreferenceSharesMember |
| r7.c2 | Total number of shares held as treasury shares/Other kinds of shares | ssmt:NumberOfSharesHeldAsTreasuryShares | xbrli:sharesItemType | instant | xbrli:shares | ssmt:OtherKindsOfSharesMember |
| r7.c3 | Total number of shares held as treasury shares/Total | ssmt:NumberOfSharesHeldAsTreasuryShares | xbrli:sharesItemType | instant | xbrli:shares | ssmt:SharesMember |