Label	Element	Value
Class P2 Prospectus \| UBS Sustainable Development Bank Bond Fund
Risk/Return:	rr_RiskReturnAbstract
Supplement to Prospectus [Text Block]	rr_SupplementToProspectusTextBlock	The UBS Funds Prospectus Supplement \| December 31, 2019 Includes: • UBS Sustainable Development Bank Bond Fund Dear Investor, The purpose of this supplement is to update the Prospectus relating to Class P2 shares of the UBS Sustainable Development Bank Bond Fund series of The UBS Funds, dated October 28, 2019, as follows:
Risk/Return [Heading]	rr_RiskReturnHeading	UBS Sustainable Development Bank Bond Fund
Performance Table Market Index Changed	rr_PerformanceTableMarketIndexChanged	The UBS Sustainable Development Bank Bond Fund's index, the Solactive UBS Global Multilateral Development Bank Bond USD 40% 1-5 Year 60% 5-10 Year Total Return Index has changed its name to the Solactive Global Multilateral Development Bank Bond USD 40% 1-5 Year 60% 5-10 Year Total Return Index.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	The UBS Sustainable Development Bank Bond Fund's index, the Solactive UBS Global Multilateral Development Bank Bond USD 40% 1-5 Year 60% 5-10 Year Total Return Index has changed its name to the Solactive Global Multilateral Development Bank Bond USD 40% 1-5 Year 60% 5-10 Year Total Return Index. Therefore, all references to the Solactive UBS Global Multilateral Development Bank Bond USD 40% 1-5 Year 60% 5-10 Year Total Return Index are deleted in their entirety and replaced with Solactive Global Multilateral Development Bank Bond USD 40% 1-5 Year 60% 5-10 Year Total Return Index.
Performance Table Closing [Text Block]	rr_PerformanceTableClosingTextBlock	PLEASE BE SURE TO RETAIN THIS IMPORTANT INFORMATION FOR FUTURE REFERENCE.

- Definition

If the Fund has annual returns for at least one calendar year, provide a table showing the Fund's (A) average annual total return; (B) average annual total return (after taxes on distributions); and (C) average annual total return (after taxes on distributions and redemption). A Money Market Fund should show only the returns described in clause (A) of the preceding sentence. All returns should be shown for 1-, 5-, and 10- calendar year periods ending on the date of the most recently completed calendar year (or for the life of the Fund, if shorter), but only for periods subsequent to the effective date of the Fund's registration statement. The table also should show the returns of an appropriate broad-based securities market index as defined in Instruction 5 to Item 22(b)(7) for the same periods. A Fund that has been in existence for more than 10 years also may include returns for the life of the Fund. A Money Market Fund may provide the Fund's 7-day yield ending on the date of the most recent calendar year or disclose a toll-free (or collect) telephone number that investors can use to obtain the Fund's current 7-day yield. For a Fund (other than a Money Market Fund or a Fund described in General Instruction C.3.(d)(iii)), provide the information in the following table with the specified captions AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, _____). For a Fund that provides annual total returns for only one calendar year or for a Fund that does not include the bar chart because it does not have annual returns for a full calendar year, modify, as appropriate, the narrative explanation required by paragraph (c)(2)(i) (e.g., by stating that the information gives some indication of the risks of an investment in the Fund by comparing the Fund's performance with a broad measure of market performance).

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