v3.26.1
Interim financial statements (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Location, Statement of Financial Position, Balance [Axis]: us-gaap:CashAndCashEquivalentsAtCarryingValue    
Debt Instrument [Line Items]    
Investments restricted for statutory reserve funds $ 3.8 $ 4.4
Location, Statement of Financial Position, Balance [Axis]: stc:InvestmentsInDebtAndEquitySecurities    
Debt Instrument [Line Items]    
Investments restricted for statutory reserve funds $ 504.7 $ 492.0