S000000885 [Member] Investment Strategy - Wasatch Micro Cap Fund	Sep. 30, 2025
Prospectus [Line Items]
Strategy [Heading]	Principal Strategies
Strategy Narrative [Text Block]	The Fund invests primarily in growing micro cap companies. 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 micro-capitalization companies. The Fund considers a company to be a micro-capitalization company if its market capitalization, at the time of purchase, is less than the larger of $1.5 billion or the market capitalization of the largest company in the Russell Microcap® Index as of its most recent reconstitution date. The Russell Microcap Index reconstitution date is typically each year on or around July 1st. As of the 2025 reconstitution date, the market capitalization of companies included in the Russell Microcap Index ranged from $23 million to $3.464 billion. The market capitalizations for the range of companies in the Russell Microcap Index are subject to change at its next reconstitution date. The Fund may invest up to 30% of its total assets at the time of purchase in equity securities (typically common stock) issued by foreign companies (companies that are incorporated in any country outside the United States and whose securities principally trade outside the United States). Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation. We focus on companies that we consider to be high quality. We use a process of “bottom-up” fundamental analysis to look for companies that we believe have the potential to grow faster than the gross domestic product (GDP) growth of the United States. Our analysis may include studying a company’s financial statements, building proprietary financial models, visiting company facilities, and meeting with executive management, suppliers and customers. The Fund seeks to purchase stocks at prices we believe are reasonable relative to our projection of a company’s long-term earnings growth rate. The Fund’s secondary objective of income is achieved when fast growing portfolio companies pay dividends, generated by cash flow, typically after achieving growth targets. The Fund may invest a large percentage of its assets (greater than 5%) in a particular region or market. 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 information technology, industrials, consumer discretionary, financials, health care, and consumer staples. The Fund may invest in initial public offerings (IPOs).
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 information technology, industrials, consumer discretionary, financials, health care, and consumer staples.

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 micro-capitalization companies. The Fund considers a company to be a micro-capitalization company if its market capitalization, at the time of purchase, is less than the larger of $1.5 billion or the market capitalization of the largest company in the Russell Microcap® Index as of its most recent reconstitution date. The Russell Microcap Index reconstitution date is typically each year on or around July 1st. As of the 2025 reconstitution date, the market capitalization of companies included in the Russell Microcap Index ranged from $23 million to $3.464 billion. The market capitalizations for the range of companies in the Russell Microcap Index are subject to change at its next reconstitution date.

The Fund may invest up to 30% of its total assets at the time of purchase in equity securities (typically common stock) issued by foreign companies (companies that are incorporated in any country outside the United States and whose securities principally trade outside the United States). Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.

We focus on companies that we consider to be high quality. We use a process of “bottom-up” fundamental analysis to look for companies that we believe have the potential to grow faster than the gross domestic product (GDP) growth of the United States. Our analysis may include studying a company’s financial statements, building proprietary financial models, visiting company facilities, and meeting with executive management, suppliers and customers.

The Fund seeks to purchase stocks at prices we believe are reasonable relative to our projection of a company’s long-term earnings growth rate. The Fund’s secondary objective of income is achieved when fast growing portfolio companies pay dividends, generated by cash flow, typically after achieving growth targets.

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 information technology, industrials, consumer discretionary, financials, health care, and consumer staples.