Investment Objectives and Goals	Oct. 31, 2025
Old Westbury All Cap Core Fund \| Old Westbury All Cap Core Fund
Prospectus [Line Items]
Risk/Return [Heading]	Old Westbury All Cap Core Fund
Old Westbury Large Cap Strategies Fund \| Old Westbury Large Cap Strategies Fund
Prospectus [Line Items]
Risk/Return [Heading]	Old Westbury Large Cap Strategies Fund
Old Westbury Small & Mid Cap Strategies Fund \| Old Westbury Small & Mid Cap Strategies Fund
Prospectus [Line Items]
Risk/Return [Heading]	Old Westbury Small & Mid Cap Strategies Fund
Old Westbury Total Equity Fund \| Old Westbury Total Equity Fund
Prospectus [Line Items]
Risk/Return [Heading]	Old Westbury Total Equity Fund
Old Westbury Credit Income Fund \| Old Westbury Credit Income Fund
Prospectus [Line Items]
Risk/Return [Heading]	Old Westbury Credit Income Fund
Old Westbury Fixed Income Fund \| Old Westbury Fixed Income Fund
Prospectus [Line Items]
Risk/Return [Heading]	Old Westbury Fixed Income Fund
Old Westbury Short-Term Bond Fund \| Old Westbury Short-Term Bond Fund
Prospectus [Line Items]
Risk/Return [Heading]	Old Westbury Short-Term Bond Fund
Old Westbury Municipal Bond Fund \| Old Westbury Municipal Bond Fund
Prospectus [Line Items]
Risk/Return [Heading]	Old Westbury Municipal Bond Fund
Old Westbury California Municipal Bond Fund \| Old Westbury California Municipal Bond Fund
Prospectus [Line Items]
Risk/Return [Heading]	Old Westbury New York Municipal Bond Fund
Old Westbury New York Municipal Bond Fund \| Old Westbury New York Municipal Bond Fund
Prospectus [Line Items]
Risk/Return [Heading]	Old Westbury New York Municipal Bond Fund