Annual Fund Operating Expenses	Oct. 31, 2025
Old Westbury Small & Mid Cap Strategies Fund \| Old Westbury Small & Mid Cap Strategies Fund
Prospectus [Line Items]
Fee Waiver or Reimbursement over Assets, Date of Termination	Oct. 31, 2028
Old Westbury Total Equity Fund \| Old Westbury Total Equity Fund
Prospectus [Line Items]
Fee Waiver or Reimbursement over Assets, Date of Termination	Oct. 31, 2028
Old Westbury Credit Income Fund \| Old Westbury Credit Income Fund
Prospectus [Line Items]
Fee Waiver or Reimbursement over Assets, Date of Termination	Oct. 31, 2028
Old Westbury Fixed Income Fund \| Old Westbury Fixed Income Fund
Prospectus [Line Items]
Fee Waiver or Reimbursement over Assets, Date of Termination	Oct. 31, 2028
Old Westbury Short-Term Bond Fund \| Old Westbury Short-Term Bond Fund
Prospectus [Line Items]
Fee Waiver or Reimbursement over Assets, Date of Termination	Oct. 31, 2028
Old Westbury Municipal Bond Fund \| Old Westbury Municipal Bond Fund
Prospectus [Line Items]
Fee Waiver or Reimbursement over Assets, Date of Termination	Oct. 31, 2028
Old Westbury California Municipal Bond Fund \| Old Westbury California Municipal Bond Fund
Prospectus [Line Items]
Fee Waiver or Reimbursement over Assets, Date of Termination	Oct. 31, 2028
Old Westbury New York Municipal Bond Fund \| Old Westbury New York Municipal Bond Fund
Prospectus [Line Items]
Fee Waiver or Reimbursement over Assets, Date of Termination	Oct. 31, 2028