S000018772 [Member] Investment Strategy - Wasatch Emerging Markets Small Cap Fund	Sep. 30, 2025
Prospectus [Line Items]
Strategy [Heading]	Principal Strategies
Strategy Narrative [Text Block]	The Fund invests primarily in small companies tied economically to emerging markets. Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities, typically common stock, of small-capitalization companies that are tied economically to emerging market countries. The Fund considers a company to be a small-capitalization company if its market capitalization, at the time of purchase, is less than the larger of $3 billion or the market capitalization of the largest company in the Morgan Stanley Capital International (MSCI) Emerging Markets Small Cap Index as of its most recent reconstitution date. As of its most recent reconstitution date, the market capitalization of companies included in the MSCI Emerging Markets Small Cap Index ranged from $120 million to $14.098 billion. The market capitalizations for the range of companies in the MSCI Emerging Markets Small Cap Index are subject to change following MSCI’s fourth quarter index review, which occurs on or around November of each year. Emerging market countries are those currently included in the MSCI Emerging Markets Index. We will consider qualifying investments to be in companies that are listed on an exchange in an emerging market country, that have at least 50% of their assets in an emerging market country, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services performed in an emerging market country. We travel extensively outside of the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis to identify individual companies that we believe have above average revenue and earnings growth potential. We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries. The Fund may invest a large percentage of its assets (greater than 5%) in a particular region or market, including Asia, India, Taiwan, and China. The Fund may invest a large percentage of its assets (greater than 5%) in a few sectors. As of the date of this Prospectus, these sectors were financials, information technology, industrials, communication services, and health care.
Strategy Portfolio Concentration [Text]	The Fund may invest a large percentage of its assets (greater than 5%) in a few sectors. As of the date of this Prospectus, these sectors were financials, information technology, industrials, communication services, and health care.

S000018772 [Member] Investment Strategy - Wasatch Emerging Markets Small Cap Fund

Sep. 30, 2025

Principal Strategies

The Fund invests primarily in small companies tied economically to emerging markets.

Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities, typically common stock, of small-capitalization companies that are tied economically to emerging market countries. The Fund considers a company to be a small-capitalization company if its market capitalization, at the time of purchase, is less than the larger of $3 billion or the market capitalization of the largest company in the Morgan Stanley Capital International (MSCI) Emerging Markets Small Cap Index as of its most recent reconstitution date. As of its most recent reconstitution date, the market capitalization of companies included in the MSCI Emerging Markets Small Cap Index ranged from $120 million to $14.098 billion. The market capitalizations for the range of companies in the MSCI Emerging Markets Small Cap Index are subject to change following MSCI’s fourth quarter index review, which occurs on or around November of each year.

Emerging market countries are those currently included in the MSCI Emerging Markets Index. We will consider qualifying investments to be in companies that are listed on an exchange in an emerging market country, that have at least 50% of their assets in an emerging market country, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services performed in an emerging market country.

We travel extensively outside of the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis to identify individual companies that we believe have above average revenue and earnings growth potential.

We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.

The Fund may invest a large percentage of its assets (greater than 5%) in a particular region or market, including Asia, India, Taiwan, and China.

The Fund may invest a large percentage of its assets (greater than 5%) in a few sectors. As of the date of this Prospectus, these sectors were financials, information technology, industrials, communication services, and health care.

Strategy Portfolio Concentration [Text]