XML 83 R57.htm IDEA: XBRL DOCUMENT
v3.23.1

Short-Term Investments - Additional Information (Details) - CNY (¥) | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract] |  |  |
Impairment on short-term investments | ¥ 0 | ¥ 0 | ¥ 0

X
- Definition Impairment loss on short-term investments. + References No definition available. + Details
Name: | stg_ImpairmentLossOnShortTermInvestments
Namespace Prefix: | stg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration