485BPOS

As filed with the Securities and Exchange Commission on February 15, 2013

Securities Act Registration No. 33-10451

Investment Company Act Registration No. 811-4920

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A

    REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933                                 X

Post-Effective Amendment No. 73                      X

and/or

    REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940         X

Amendment No. 75                        X

(Check appropriate box or boxes)

WASATCH FUNDS TRUST

(Exact Name of Registrant as Specified in Charter)

150 Social Hall Avenue

4th Floor

Salt Lake City, Utah 84111

(Address of Principal Executive Offices)

Registrant’s Telephone Number, including Area Code: (801) 533-0777

(Name and Address of Agent for Service)	Copy to:
Samuel S. Stewart, Jr. Wasatch Advisors, Inc. 150 Social Hall Avenue, 4th Floor Salt Lake City, Utah 84111	Eric F. Fess Chapman and Cutler LLP 111 West Monroe Street Chicago, IL 60603

    Approximate Date of Proposed Public Offering: As soon as practicable following effectiveness.

It is proposed that this filing will become effective:

(X) immediately upon filing pursuant to paragraph (b)

(  ) on             pursuant to paragraph (b)

(  ) 60 days after filing pursuant to paragraph (a)(1)

(  ) on             pursuant to paragraph (a)(1)

(  ) 75 days after filing pursuant to paragraph (a)(2)

(  ) on             pursuant to paragraph (a)(2) of Rule 485.

If appropriate, check the following box:

(  ) this Post-Effective Amendment designates a new effective date for a previously filed Post-Effective Amendment.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended and the Investment Company Act of 1940, as amended, the Registrant certifies that this Post-Effective Amendment No. 73 to the Registration Statement meets all the requirements for effectiveness pursuant to Rule 485(b) of the Securities Act of 1933, as amended, and the Registrant has duly caused this Post-Effective Amendment No. 73 under the Securities Act of 1933, as amended and Post-Effective Amendment No. 75 under the Investment Company Act of 1940, as amended to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Salt Lake City, and the State of Utah on the 15^th day of February 2013.

WASATCH FUNDS TRUST

By         /s/ Samuel S. Stewart, Jr.

             Samuel S. Stewart, Jr., Ph.D.,

             President

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed below by the following persons in the capacities and on the date indicated.

Signature	Title	Date
/s/ Samuel S. Stewart, Jr. Samuel S. Stewart, Jr., Ph.D.	President and Trustee (principal executive officer)	February 15, 2013
/s/ Cindy B. Firestone Cindy B. Firestone	Treasurer   (principal financial and accounting officer)	February 15, 2013
James U. Jensen* James U. Jensen, Esquire	Trustee	February 15, 2013
William R. Swinyard* William R. Swinyard	Trustee	February 15, 2013
D. James Croft* D. James Croft	Trustee	February 15, 2013
Miriam M. Allison* Miriam M. Allison	Trustee	February 15, 2013
Heikki Rinne* Heikki Rinne	Trustee	February 15, 2013

/s/ Russell L. Biles

Russell L. Biles

*Attorney-in-Fact

February 15, 2013

*Signed pursuant to powers of attorney are incorporated herein by reference to Exhibit (q) in Post-Effective Amendment No. 50 to the Registrant’s Registration Statement on Form N-1A filed with the Commission on March 31, 2010 and a power of attorney incorporated herein by reference to Exhibit q-1 in Post-Effective Amendment No. 65 to the Registrant’s Registration Statement on Form N-1A filed with the Commission on October 2, 2012.

Exhibit Index

Exhibit No.
EX-101.INS	XBRL Instance Document
EX-101.SCH	XBRL Taxonomy Extension Schema Document
EX-101.CAL	XBRL Taxonomy Extension Calculation Linkbase
EX-101.DEF	XBRL Taxonomy Extension Definition Linkbase
EX-101.LAB	XBRL Taxonomy Extension Labels Linkbase
EX-101.PRE	XBRL Taxonomy Extension Presentation Linkbase

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Wasatch World Innovators Fund

WASATCH WORLD INNOVATORS FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Wasatch World Innovators Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Wasatch World Innovators Fund Investor Class Shares
Management Fee		1.50%
Distribution/Service (12b-1) Fee		none
Other Expenses		0.35%
Acquired Fund Fees and Expenses		0.02%
Total Annual Fund Operating Expenses	[1]	1.87%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Wasatch World Innovators Fund Investor Class	190	588	1,012	2,193

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 66% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in domestic and foreign growth companies that we believe are innovators in their respective sectors or industries.
Typically, the Fund’s assets will be invested in at least three developed countries including the U.S. The Fund may invest in securities issued by companies domiciled in emerging markets without limitation. Under normal market conditions, a significant portion of the Fund’s assets (typically between 40% and 80% at the time of purchase) will be invested outside the U.S.
We will use a process of “bottom up” fundamental analysis to invest in companies of any size. However, because innovative companies are rapidly evolving, we expect to invest a significant portion of the Fund’s assets in early stage companies and small to mid-size companies with market capitalizations of less than US $5 billion at the time of purchase.
We have defined two broad categories that we believe are critical to identifying companies with outstanding investment potential. The first is companies that possess valuable intellectual property. The second is companies that are innovators in their respective sectors or industries.
The Fund may invest a large percentage of its assets in a few sectors, including information technology, health care, consumer discretionary, industrials and financials.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics).
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Technology and Science Stock Risk. Stocks of science and information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market. Science companies may be affected by the same risks as technology companies.
Health Care Stock Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com. Effective April 1, 2011, the Wasatch World Innovators Fund changed its name from the Wasatch Global Science & Technology Fund and changed its principal strategies and primary comparison benchmark index. The bar chart, best and worst quarterly returns and average annual total return table include performance prior to these changes.

WASATCH WORLD INNOVATORS FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/03	28.94%
Worst — 12/31/08	-30.07%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Wasatch World Innovators Fund		1 Year	5 Years	10 Years
Investor Class		18.04%	3.98%	10.18%
Investor Class Return after taxes on distributions		18.04%	3.97%	9.86%
Investor Class Return after taxes on distributions and sale of Fund shares		11.72%	3.41%	8.98%
MSCI All Country (AC) World Investable Markets Index (IMI) (reflects no deductions for fees, expenses or taxes)	[1]	16.38%	(0.73%)	8.60%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.95% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). Acquired Fund Fees and Expenses are not included in the expense limitation. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date. There were no reimbursements for the Investor Class shares of the Fund during 2012. The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund’s most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

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Institutional Class | Wasatch Small Cap Value Fund

WASATCH SMALL CAP VALUE FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Institutional Class Wasatch Small Cap Value Fund Institutional Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Institutional Class Wasatch Small Cap Value Fund Institutional Class Shares
Management Fee	[1]	1.00%
Distribution/Service (12b-1) Fee	[1]	none
Other Expenses	[1]	0.66%
Total Annual Fund Operating Expenses	[1][2]	1.66%
Expense Reimbursement	[1]	(0.51%)
Total Annual Fund Operating Expenses After Expense Reimbursement	[1]	1.15%

EXAMPLE

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Institutional Class Wasatch Small Cap Value Fund	117	473	853	1,922

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 55% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in small companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets in the equity securities of small companies with market capitalizations of less than $2.5 billion at the time of purchase.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly traded in the United States are not defined as foreign companies and are not subject to this limitation.
The Fund may also invest in growth companies if the Advisor believes that current valuation is at a sufficient discount to the projected long-term earnings growth rate.
We use a “bottom-up” process of fundamental analysis to look for individual companies that we believe are temporarily undervalued but have significant potential for stock price appreciation. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
We typically look for companies that we believe fall into one of these three categories at the time of purchase:

• Undiscovered Gems — Companies with good growth potential which have yet to be broadly discovered by Wall Street analysts, thus leaving them attractively undervalued relative to their expected growth.
• Fallen Angels — High quality growth companies that have experienced a temporary setback and therefore have appealing valuations relative to their long term growth potential.
• Quality Value — Quality companies with earnings potential that is not fully reflected in their stock prices.

The Fund may invest a large percentage of its assets in a few sectors, including industrials, information technology, financials, consumer discretionary, health care and energy.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Value Investing Risk. Value investing attempts to identify strong companies whose stocks are selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

HISTORICAL PERFORMANCE

The following tables provide information on how the Fund has performed over time. The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. The Fund’s Institutional Class commenced operations on January 31, 2012. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH SMALL CAP VALUE FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/09	33.91%
Worst — 12/31/08	-34.04%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Institutional Class Wasatch Small Cap Value Fund	1 Year	5 Years	10 Years
Investor Class	16.52%	2.46%	9.49%
Investor Class Return after taxes on distributions	16.52%	2.46%	8.05%
Investor Class Return after taxes on distributions and sale of Fund shares	10.74%	2.11%	7.96%
Russell 2000® Value Index (reflects no deductions for fees, expenses or taxes)	18.05%	3.55%	9.50%
Russell 2000® Index (reflects no deductions for fees, expenses or taxes)	16.35%	3.56%	9.72%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Fund's operating expenses have been restated to reflect a reduction in the management fee, effective January 31, 2012, as if such changes had been in effect during the fiscal year ended September 30, 2012. The information has been restated to better reflect anticipated expenses of the Fund.

[2] The Advisor has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.15% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

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Risk/Return:

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Registrant Name

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WASATCH FUNDS TRUST

Prospectus Date

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Jan. 31, 2013

Wasatch International Growth Fund

Risk/Return:

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Risk/Return [Heading]

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WASATCH INTERNATIONAL GROWTH FUND — Summary

Objective [Heading]

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INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

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The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

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FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

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ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

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PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 44% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

44.00%

Expense Example [Heading]

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EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

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PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

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The Fund invests primarily in foreign growth companies.
Under normal market conditions, we will invest the Fund’s assets in the equity securities of foreign companies with market capitalizations of less than US$5 billion at the time of purchase. Under normal market conditions, the Fund will invest in at least five of the countries included in the Morgan Stanley Capital International (MSCI) All Country (AC) World Ex-U.S.A. Small Cap Index.
The Fund may invest a significant amount of its total assets (5% to 70% under normal market conditions) at the time of purchase in securities issued by companies domiciled in emerging markets. Emerging market countries are those currently included in the MSCI EFM (Emerging + Frontier Markets) Index. These companies typically are located in the Asia-Pacific region, Eastern Europe, the Middle East, Central and South America, and Africa.
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 may invest in early stage companies if we believe they have outstanding long-term 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 in a few sectors, including consumer discretionary, financials, industrials, information technology, materials, consumer staples, health care and energy.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

Risk Lose Money [Text]

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All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

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HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

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The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide information on how the Investor Class of the Fund has performed over time.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH INTERNATIONAL GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns*

Best — 6/30/09	41.88%
Worst — 9/30/08	-28.61%

^[1]

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch International Growth Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.25%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Interest Expense

rr_Component1OtherExpensesOverAssets

0.01%

Other Expenses

rr_OtherExpensesOverAssets

0.31%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.57%

^[2]

1 Year

rr_ExpenseExampleYear01

160

3 Years

rr_ExpenseExampleYear03

496

5 Years

rr_ExpenseExampleYear05

856

10 Years

rr_ExpenseExampleYear10

1,868

2003

rr_AnnualReturn2003

44.96%

2004

rr_AnnualReturn2004

22.93%

2005

rr_AnnualReturn2005

18.37%

2006

rr_AnnualReturn2006

23.79%

2007

rr_AnnualReturn2007

12.47%

2008

rr_AnnualReturn2008

(53.93%)

2009

rr_AnnualReturn2009

64.19%

2010

rr_AnnualReturn2010

34.24%

2011

rr_AnnualReturn2011

(12.04%)

2012

rr_AnnualReturn2012

33.08%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

41.88%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(28.61%)

1 Year

rr_AverageAnnualReturnYear01

33.08%

5 Years

rr_AverageAnnualReturnYear05

3.52%

10 Years

rr_AverageAnnualReturnYear10

13.32%

Wasatch International Growth Fund | Return after taxes on distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

33.01%

5 Years

rr_AverageAnnualReturnYear05

3.48%

10 Years

rr_AverageAnnualReturnYear10

12.68%

Wasatch International Growth Fund | Return after taxes on distributions and sale of Fund shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

21.60%

5 Years

rr_AverageAnnualReturnYear05

3.00%

10 Years

rr_AverageAnnualReturnYear10

11.83%

Wasatch International Growth Fund | MSCI AC World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

18.52%

^[3]

5 Years

rr_AverageAnnualReturnYear05

(0.39%)

^[3]

10 Years

rr_AverageAnnualReturnYear10

13.16%

^[3]

Wasatch International Growth Fund | MSCI World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

17.48%

^[3]

5 Years

rr_AverageAnnualReturnYear05

(0.70%)

^[3]

10 Years

rr_AverageAnnualReturnYear10

12.04%

^[3]

[1] Prior to January 31, 2007, the Fund primarily invested in companies with market capitalizations of less than US$2 billion at the time of purchase.

[2] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.75% until at least January 31, 2014 (excluding interest, interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). There were no reimbursements for the Investor Class shares of the Fund during 2012. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

[3] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Wasatch Micro Cap Fund

WASATCH MICRO CAP FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital. Income is an objective only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Wasatch Micro Cap Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Wasatch Micro Cap Fund Investor Class Shares
Management Fee		1.95%
Distribution/Service (12b-1) Fee		none
Other Expenses		0.19%
Total Annual Fund Operating Expenses	[1]	2.14%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Wasatch Micro Cap Fund Investor Class	217	670	1,149	2,472

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 25% of the average value of its portfolio.

PRINCIPAL STRATEGIES

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 in the equity securities of micro cap companies with market capitalizations of less than $1 billion at the time of purchase.
The Fund may invest up to 30% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly 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, and we use a process of “bottom up” fundamental analysis to look for individual companies that we believe have superior growth potential. 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 may invest a large percentage of its assets in a few sectors, including information technology, health care, industrials, financials and consumer discretionary.
The Fund may invest in initial public offerings (IPOs).

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap Company Stock Risk. Micro cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH MICRO CAP FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/03	27.44%
Worst — 12/31/08	-31.16%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Wasatch Micro Cap Fund	1 Year	5 Years	10 Years
Investor Class	11.85%	(0.11%)	8.36%
Investor Class Return after taxes on distributions	11.85%	(0.13%)	7.13%
Investor Class Return after taxes on distributions and sale of Fund shares	7.70%	(0.11%)	7.16%
Russell Microcap® Index (reflects no deductions for fees, expenses or taxes)	19.75%	1.46%	8.42%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 2.25% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). There were no reimbursements for the Investor Class shares of the Fund during 2012. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Wasatch International Opportunities Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH INTERNATIONAL OPPORTUNITIES FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 41% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

41.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in foreign micro cap companies.
Under normal market conditions, we will invest the Fund’s assets in equity securities of foreign companies with market capitalizations of less than US$1 billion at the time of purchase. Under normal market conditions, the Fund will invest in at least five of the countries included in the Morgan Stanley Capital International (MSCI) All Country (AC) World Ex-U.S.A. Small Cap Index.
The Fund may invest a significant amount of its total assets (20% to 70% under normal market conditions) at the time of purchase in securities issued by companies domiciled in emerging markets. Emerging market countries are those currently included in the MSCI EFM (Emerging Frontier Markets) Index. These companies typically are located in the Asia-Pacific region, Eastern Europe, the Middle East, Central and South America, and Africa.
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 may invest in early stage companies if we believe they have outstanding long-term 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 in a few sectors, including industrials, consumer discretionary, information technology, materials, consumer staples, energy, financials and health care.
The Fund may also invest in initial public offerings (IPOs).

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap Company Stock Risk. Micro cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide information on how the Investor Class of the Fund has performed over time.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH INTERNATIONAL OPPORTUNITIES FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/09	44.35%
Worst — 9/30/08	-27.60%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After tax-returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After tax-returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch International Opportunities Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.95%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.53%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

2.48%

^[1]

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.23%)

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

2.25%

1 Year

rr_ExpenseExampleYear01

228

3 Years

rr_ExpenseExampleYear03

751

5 Years

rr_ExpenseExampleYear05

1,300

10 Years

rr_ExpenseExampleYear10

2,799

2006

rr_AnnualReturn2006

31.50%

2007

rr_AnnualReturn2007

15.17%

2008

rr_AnnualReturn2008

(54.73%)

2009

rr_AnnualReturn2009

75.05%

2010

rr_AnnualReturn2010

26.10%

2011

rr_AnnualReturn2011

(16.01%)

2012

rr_AnnualReturn2012

31.79%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

44.35%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(27.60%)

1 Year

rr_AverageAnnualReturnYear01

31.79%

5 Years

rr_AverageAnnualReturnYear05

2.04%

Since Inception

rr_AverageAnnualReturnSinceInception

9.20%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 27, 2005

Wasatch International Opportunities Fund | Return after taxes on distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

31.79%

5 Years

rr_AverageAnnualReturnYear05

1.49%

Since Inception

rr_AverageAnnualReturnSinceInception

8.09%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 27, 2005

Wasatch International Opportunities Fund | Return after taxes on distributions and sale of Fund shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

20.67%

5 Years

rr_AverageAnnualReturnYear05

1.59%

Since Inception

rr_AverageAnnualReturnSinceInception

7.74%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 27, 2005

Wasatch International Opportunities Fund | MSCI AC World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

18.52%

^[2]

5 Years

rr_AverageAnnualReturnYear05

(0.39%)

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

6.76%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 27, 2005

^[2]

Wasatch International Opportunities Fund | MSCI World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

17.48%

^[2]

5 Years

rr_AverageAnnualReturnYear05

(0.70%)

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

5.00%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 27, 2005

^[2]

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 2.25% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

[2] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Wasatch Strategic Income Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH STRATEGIC INCOME FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s primary investment objective is to capture current income.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

A secondary objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 57% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

57.00%

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees

The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund’s most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in income-producing securities.
Under normal market conditions, we will invest the Fund’s assets in income-producing domestic and foreign securities, including equity securities (common stock, preferred stocks and securities convertible into common stock) and fixed income securities of companies of all market capitalizations. The Fund is not managed as a balanced portfolio. At times, one type of security may make up a substantial portion of the Fund, while other types may have minimal or no representation.
The Fund may invest its assets in securities issued by foreign companies in developed countries without limit. To a lesser extent, the Fund may invest in foreign companies in emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly traded in the United States are not defined as foreign companies.
In our search for investments, we maintain the flexibility to invest in companies from a variety of industries. The Fund, however, does have a concentration in the financials sector — meaning that at least 25% of the Fund’s total assets will be invested in securities of issuers in the group of industries in the financials sector. For both domestic and foreign securities, we define the group of industries comprising the financials sector to include, among others, Banks (Commercial Banks, Thrifts and Mortgage Finance), Diversified Financial Companies (Diversified Financial Services, Consumer Finance, Capital Markets), Finance Companies, Financial Data Processing Services and Systems, Finance Companies (Small Loan), Financial Information Services, Insurance Companies (Life, Multi-Line, Property-Casualty), Investment Management Companies, Real Estate Companies (Real Estate Investment Trusts [REITs], Real Estate Management and Development Companies), Rental and Leasing Services (Commercial), Savings and Loans, and Securities Brokerage and Services.
The Fund may invest a large percentage of its assets in a few sectors, including financials, information technology and health care.
The Fund may invest in exchange-traded funds (ETFs).
The Fund may make short sales of securities, and may also use derivatives such as put and call options and futures contracts for hedging and non-hedging purposes. The Fund may write put and call options subject to applicable law and SEC guidelines.
In the selection of equity securities, we use “bottom up” fundamental analysis to identify individual companies with attractive, sustainable dividend yields or the potential for dividend growth. In certain situations, the Fund may acquire non-income producing securities if we believe the company has the potential to pay dividends in the future. 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.
Characteristics we consider when investing in equity securities generally include:

• Attractive, sustainable dividend yields or the potential for dividend growth.
• Experienced top management.
• Sustainable competitive advantage.
• Stable demand for products and services.
• Ability to capitalize on favorable long-term trends.

The Fund’s investments in fixed income securities may include domestic and foreign corporate bonds with a variety of maturities (e.g., long-term, intermediate or short-term) and credit qualities (e.g., investment grade or non-investment grade). At certain times the Fund may emphasize one particular maturity or credit quality. The Fund may invest in non-investment grade securities without limitation. The Fund may also invest in U.S. Treasury securities and the debt obligations of foreign governments.
Characteristics we consider when investing in fixed income securities generally include:

• Rates of current income.
• Credit quality of the issuer.
• Maturity, duration and other characteristics of the obligation.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small and mid cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it will have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Derivatives Risk. The Fund may suffer a loss from its use of put and call options and futures contracts, which are forms of derivatives. Derivatives can amplify a gain or loss, potentially earning or losing substantially more money than the actual cost of the derivative instrument, with the potential for unlimited losses on certain instruments. Derivatives may be difficult to value, may become illiquid, and may affect the timing and character of taxes payable by shareholders.
Short Sales Risk. The Fund may make short sales of securities, which means it may experience a loss if the market price of the security increases between the date of the short sale and the date the security is replaced. Short sales may reduce a Fund’s returns or increase volatility.
Investment Companies Risk. The Fund may invest in shares of other investment companies, including foreign and domestic registered and unregistered open-end funds, closed-end funds, and unit investment trusts and exchange-traded funds noted below. Investing in another investment company subjects the Fund to the same risks associated with investing in the securities held by the applicable investment company and the investment strategies employed by such funds (such as the use of leverage). In addition, the benefit of investing in another investment company is largely dependent on the skill of the investment advisor of the underlying company and whether the associated fees and costs involved with investing in such company are offset by the potential gains. As a shareholder in an investment company, a fund will bear its ratable share of that investment company’s expenses including advisory and administrative fees. Shareholders would therefore be subject to duplicative expenses to the extent that the Fund invests in other investment companies.
Exchange-Traded Funds (ETFs) Risk. ETFs are investment companies that are bought and sold on a securities exchange. Shares of ETFs are redeemable only in larger aggregations of a specified number of shares and generally on an in-kind basis. When the Fund invests in an ETF, it will bear additional expenses based on its pro rata share of the ETF’s operating expenses. In addition, the Fund will incur brokerage costs when purchasing and selling shares of ETFs. The risk of owning an ETF generally reflects the risks of the underlying securities held by the ETF and investment strategies employed by such ETF (such as the use of leverage). The market price may also fluctuate due to the supply and demand of the ETF’s shares on the exchange upon which its shares are traded. Lack of liquidity in an ETF could result in the ETF being more volatile than the underlying portfolio of securities. In addition, because of ETF expenses, compared to owning the underlying securities directly, it may be more costly to own an ETF.
REIT Risk. Investments in real estate investment trusts (REITs) subject the Fund to risks associated with the direct ownership of real estate. The value of securities of REITs can be affected by changes in real estate values and rental income, property taxes, interest rates, tax and regulatory requirements and the management skill and creditworthiness of the issuer. In addition, the value of a REIT can depend on the structure and cash flow generated by the REIT and REITs may not have diversified holdings. Because REITs are pooled investment vehicles that have expenses of their own, the Fund will indirectly bear its proportionate share of those expenses.
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. Credit risk is affected by the issuer’s credit status, and is generally higher for non-investment grade securities.
Interest Rate Risk. Interest rate risk is the risk that a debt security’s value will decline due to changes in market interest rates. Even though some interest-bearing securities offer a stable stream of income, their prices will fluctuate with changes in interest rates.
Non-Investment Grade Securities Risk. Non-investment grade securities (also known as “high yield” or “junk bonds”), those rated below investment grade by the primary rating agencies (e.g., below BB/Ba by S&P/Moody’s) tend to have more volatile prices and increased price sensitivity to changing interest rates and adverse economic and business developments than investment grade securities. In addition, compared to investments in investment grade securities, investments in non-investment grade securities are subject to greater risk of loss due to default or decline in credit quality. There is a greater likelihood that adverse economic or company-specific events will make the issuer unable to make interest and/or principal payments, and more susceptible to negative market sentiment, leading to depressed prices and decreased liquidity.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional comparison index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide information on how the Investor Class of the Fund has performed over time.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH STRATEGIC INCOME FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/09	21.21%
Worst — 12/31/08	-28.22%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch Strategic Income Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

0.70%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.44%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.09%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.23%

^[1]

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.19%)

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.04%

1 Year

rr_ExpenseExampleYear01

106

3 Years

rr_ExpenseExampleYear03

373

5 Years

rr_ExpenseExampleYear05

660

10 Years

rr_ExpenseExampleYear10

1,477

2007

rr_AnnualReturn2007

(2.02%)

2008

rr_AnnualReturn2008

(40.57%)

2009

rr_AnnualReturn2009

38.04%

2010

rr_AnnualReturn2010

19.87%

2011

rr_AnnualReturn2011

6.35%

2012

rr_AnnualReturn2012

11.29%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

21.21%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(28.22%)

1 Year

rr_AverageAnnualReturnYear01

11.29%

5 Years

rr_AverageAnnualReturnYear05

3.08%

Since Inception

rr_AverageAnnualReturnSinceInception

4.53%

Inception Date

rr_AverageAnnualReturnInceptionDate

Feb. 01, 2006

Wasatch Strategic Income Fund | Return after taxes on distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

10.73%

5 Years

rr_AverageAnnualReturnYear05

2.05%

Since Inception

rr_AverageAnnualReturnSinceInception

2.73%

Inception Date

rr_AverageAnnualReturnInceptionDate

Feb. 01, 2006

Wasatch Strategic Income Fund | Return after taxes on distributions and sale of Fund shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

7.58%

5 Years

rr_AverageAnnualReturnYear05

2.04%

Since Inception

rr_AverageAnnualReturnSinceInception

2.84%

Inception Date

rr_AverageAnnualReturnInceptionDate

Feb. 01, 2006

Wasatch Strategic Income Fund | S&P 500 Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

16.00%

5 Years

rr_AverageAnnualReturnYear05

1.66%

Since Inception

rr_AverageAnnualReturnSinceInception

3.78%

Inception Date

rr_AverageAnnualReturnInceptionDate

Feb. 01, 2006

Wasatch Strategic Income Fund | Barclays Capital U.S. Aggregate Bond Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.22%

5 Years

rr_AverageAnnualReturnYear05

5.95%

Since Inception

rr_AverageAnnualReturnSinceInception

5.93%

Inception Date

rr_AverageAnnualReturnInceptionDate

Feb. 01, 2006

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 0.95% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, and extraordinary expenses). Acquired Fund Fees and Expenses are not included in the expense limitation. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date. The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund's most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Wasatch World Innovators Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH WORLD INNOVATORS FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 66% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

66.00%

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees

The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund’s most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in domestic and foreign growth companies that we believe are innovators in their respective sectors or industries.
Typically, the Fund’s assets will be invested in at least three developed countries including the U.S. The Fund may invest in securities issued by companies domiciled in emerging markets without limitation. Under normal market conditions, a significant portion of the Fund’s assets (typically between 40% and 80% at the time of purchase) will be invested outside the U.S.
We will use a process of “bottom up” fundamental analysis to invest in companies of any size. However, because innovative companies are rapidly evolving, we expect to invest a significant portion of the Fund’s assets in early stage companies and small to mid-size companies with market capitalizations of less than US $5 billion at the time of purchase.
We have defined two broad categories that we believe are critical to identifying companies with outstanding investment potential. The first is companies that possess valuable intellectual property. The second is companies that are innovators in their respective sectors or industries.
The Fund may invest a large percentage of its assets in a few sectors, including information technology, health care, consumer discretionary, industrials and financials.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics).
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Technology and Science Stock Risk. Stocks of science and information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market. Science companies may be affected by the same risks as technology companies.
Health Care Stock Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com. Effective April 1, 2011, the Wasatch World Innovators Fund changed its name from the Wasatch Global Science & Technology Fund and changed its principal strategies and primary comparison benchmark index. The bar chart, best and worst quarterly returns and average annual total return table include performance prior to these changes.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide information on how the Investor Class of the Fund has performed over time.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH WORLD INNOVATORS FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/03	28.94%
Worst — 12/31/08	-30.07%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch World Innovators Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.50%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.35%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.02%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.87%

^[1]

1 Year

rr_ExpenseExampleYear01

190

3 Years

rr_ExpenseExampleYear03

588

5 Years

rr_ExpenseExampleYear05

1,012

10 Years

rr_ExpenseExampleYear10

2,193

2003

rr_AnnualReturn2003

48.04%

2004

rr_AnnualReturn2004

(4.05%)

2005

rr_AnnualReturn2005

16.43%

2006

rr_AnnualReturn2006

15.95%

2007

rr_AnnualReturn2007

13.17%

2008

rr_AnnualReturn2008

(52.75%)

2009

rr_AnnualReturn2009

67.48%

2010

rr_AnnualReturn2010

24.46%

2011

rr_AnnualReturn2011

4.53%

2012

rr_AnnualReturn2012

18.04%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2003

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

28.94%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(30.07%)

1 Year

rr_AverageAnnualReturnYear01

18.04%

5 Years

rr_AverageAnnualReturnYear05

3.98%

10 Years

rr_AverageAnnualReturnYear10

10.18%

Wasatch World Innovators Fund | Return after taxes on distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

18.04%

5 Years

rr_AverageAnnualReturnYear05

3.97%

10 Years

rr_AverageAnnualReturnYear10

9.86%

Wasatch World Innovators Fund | Return after taxes on distributions and sale of Fund shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

11.72%

5 Years

rr_AverageAnnualReturnYear05

3.41%

10 Years

rr_AverageAnnualReturnYear10

8.98%

Wasatch World Innovators Fund | MSCI All Country (AC) World Investable Markets Index (IMI) (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

16.38%

^[2]

5 Years

rr_AverageAnnualReturnYear05

(0.73%)

^[2]

10 Years

rr_AverageAnnualReturnYear10

8.60%

^[2]

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.95% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). Acquired Fund Fees and Expenses are not included in the expense limitation. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date. There were no reimbursements for the Investor Class shares of the Fund during 2012. The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund’s most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

[2] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Institutional Class | Wasatch Core Growth Fund

WASATCH CORE GROWTH FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s primary investment objective is long-term growth of capital.

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Institutional Class Wasatch Core Growth Fund Institutional Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Institutional Class Wasatch Core Growth Fund Institutional Class Shares
Management Fee		1.00%
Distribution/Service (12b-1) Fee		none
Other Expenses		0.55%
Total Annual Fund Operating Expenses	[1]	1.55%
Expense Reimbursement		(0.43%)
Total Annual Fund Operating Expenses After Expense Reimbursement		1.12%

EXAMPLE

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Institutional Class Wasatch Core Growth Fund	114	447	803	1,809

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 28% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in smaller growing companies at reasonable prices.
Under normal market conditions, we will invest at least 65% of the Fund’s net assets in the equity securities of growing companies. These companies are usually small to mid-size with market capitalizations of less than $5 billion at the time of purchase.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly 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 individual companies that we believe are stable and have the potential to grow steadily for long periods of time. 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 may invest a large percentage of its assets in a few sectors, including industrials, financials, consumer discretionary, information technology and health care.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small and mid cap stocks may be very sensitive to changing economic conditions and market downturns.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

HISTORICAL PERFORMANCE

The following tables provide information on how the Fund has performed over time. The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total returns table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index, and an additional index composed of securities similar to those held by the Fund. The Fund’s Institutional Class commenced operations on January 31, 2012. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH CORE GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/09	29.50%
Worst — 12/31/08	-27.03%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Institutional Class Wasatch Core Growth Fund	1 Year	5 Years	10 Years
Investor Class	19.19%	4.81%	9.58%
Investor Class Return after taxes on distributions	19.19%	4.71%	8.80%
Investor Class Return after taxes on distributions and sale of Fund shares	12.48%	4.07%	8.28%
Russell 2000® Index (reflects no deductions for fees, expenses or taxes)	16.35%	3.56%	9.72%
Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)	14.59%	3.49%	9.80%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Advisor has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.12% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Wasatch Micro Cap Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH MICRO CAP FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital. Income is an objective only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 25% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

25.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

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 in the equity securities of micro cap companies with market capitalizations of less than $1 billion at the time of purchase.
The Fund may invest up to 30% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly 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, and we use a process of “bottom up” fundamental analysis to look for individual companies that we believe have superior growth potential. 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 may invest a large percentage of its assets in a few sectors, including information technology, health care, industrials, financials and consumer discretionary.
The Fund may invest in initial public offerings (IPOs).

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap Company Stock Risk. Micro cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide information on how the Investor Class of the Fund has performed over time.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH MICRO CAP FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/03	27.44%
Worst — 12/31/08	-31.16%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch Micro Cap Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.95%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.19%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

2.14%

^[1]

1 Year

rr_ExpenseExampleYear01

217

3 Years

rr_ExpenseExampleYear03

670

5 Years

rr_ExpenseExampleYear05

1,149

10 Years

rr_ExpenseExampleYear10

2,472

2003

rr_AnnualReturn2003

49.84%

2004

rr_AnnualReturn2004

12.70%

2005

rr_AnnualReturn2005

11.02%

2006

rr_AnnualReturn2006

17.05%

2007

rr_AnnualReturn2007

2.23%

2008

rr_AnnualReturn2008

(49.29%)

2009

rr_AnnualReturn2009

44.37%

2010

rr_AnnualReturn2010

29.76%

2011

rr_AnnualReturn2011

(6.39%)

2012

rr_AnnualReturn2012

11.85%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2003

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

27.44%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(31.16%)

1 Year

rr_AverageAnnualReturnYear01

11.85%

5 Years

rr_AverageAnnualReturnYear05

(0.11%)

10 Years

rr_AverageAnnualReturnYear10

8.36%

Wasatch Micro Cap Fund | Return after taxes on distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

11.85%

5 Years

rr_AverageAnnualReturnYear05

(0.13%)

10 Years

rr_AverageAnnualReturnYear10

7.13%

Wasatch Micro Cap Fund | Return after taxes on distributions and sale of Fund shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

7.70%

5 Years

rr_AverageAnnualReturnYear05

(0.11%)

10 Years

rr_AverageAnnualReturnYear10

7.16%

Wasatch Micro Cap Fund | Russell Microcap® Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

19.75%

5 Years

rr_AverageAnnualReturnYear05

1.46%

10 Years

rr_AverageAnnualReturnYear10

8.42%

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 2.25% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). There were no reimbursements for the Investor Class shares of the Fund during 2012. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

XML

Institutional Class | Wasatch Large Cap Value Fund

WASATCH LARGE CAP VALUE FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s investment objectives are to seek capital appreciation and income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Institutional Class Wasatch Large Cap Value Fund Institutional Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Institutional Class Wasatch Large Cap Value Fund Institutional Class Shares
Management Fee		0.90%
Distribution/Service (12b-1) Fee		none
Other Expenses		0.41%
Total Annual Fund Operating Expenses	[1]	1.31%
Expense Reimbursement		(0.33%)
Total Annual Fund Operating Expenses After Expense Reimbursement		0.98%

EXAMPLE

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Institutional Class Wasatch Large Cap Value Fund	100	383	687	1,550

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 14% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in equity securities.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets in equity securities (including common stock, preferred stock and securities convertible into common stocks) of companies with market capitalizations of over $5 billion at the time of purchase.
The Fund typically invests in the securities of companies that we believe will pay above average dividends or interest.
When evaluating a potential investment for the Fund, we employ a comprehensive valuation analysis intended to establish a range for fair valuation or intrinsic company value, with a particular emphasis on company fundamentals. The initial valuation review may include:

• Calculating and reviewing standard ratios such as price-to-sales, price-to-book, price-to-earnings, and price/earnings-to-growth.
• Modified discounted cash flow models with sensitivity analysis for changes to revenue growth rates, operating margins, outstanding share counts, earnings multiples, and tangible book value.
• Changing sector and company specific outlooks due to subjective factors, including globalization of capital, labor and process knowledge, as well as increasing information and price transparency.

The Fund may invest a large percentage of its assets in a few sectors, including energy, financials, information technology, consumer staples, health care and industrials.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Value Investing Risk. Value investing attempts to identify strong companies whose stocks are selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

HISTORICAL PERFORMANCE

The Fund’s Investor Class shares commenced operations on December 15, 2008 upon the reorganization of the 1st Source Monogram Income Equity Fund, the Fund’s predecessor fund (the “Predecessor Fund”), into the Fund. With the reorganization, the Fund assumed the financial and performance history of the Predecessor Fund. The following tables provide an indication of the historical risk of an investment in the Fund (and Predecessor Fund for periods prior to December 15, 2008). The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to that of a broad-based market index. Past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. In addition, the Predecessor Fund was advised by a different investment advisor and subject to different expenses, which may have produced different investment results. The Fund, however, has two portfolio managers, one of which was also the portfolio manager of the Predecessor Fund. The Fund’s Institutional Class commenced operations on January 31, 2012. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH LARGE CAP VALUE FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/03	15.78%
Worst — 12/31/08	-19.38%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Institutional Class Wasatch Large Cap Value Fund	1 Year	5 Years	10 Years
Investor Class	10.55%	0.22%	8.58%
Investor Class Return after taxes on distributions	10.17%	(0.18%)	7.64%
Investor Class Return after taxes on distributions and sale of Fund shares	7.35%	0.02%	7.23%
Russell 1000® Value Index (reflects no deductions for fees, expenses or taxes)	17.51%	0.59%	7.38%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Advisor has contractually agreed to reimburse Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 0.98% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

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Wasatch Micro Cap Value Fund

WASATCH MICRO CAP VALUE FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Wasatch Micro Cap Value Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Wasatch Micro Cap Value Fund Investor Class Shares
Management Fee		1.95%
Distribution/Service (12b-1) Fee		none
Other Expenses		0.36%
Acquired Fund Fees and Expenses		0.01%
Total Annual Fund Operating Expenses	[1]	2.32%
Expense Reimbursement		(0.06%)
Total Annual Fund Operating Expenses After Expense Reimbursement		2.26%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Wasatch Micro Cap Value Fund Investor Class	229	719	1,235	2,651

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 78% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in micro cap companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets in the equity securities of micro cap companies with market capitalizations of less than $1 billion at the time of purchase.
The Fund may invest up to 30% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly traded in the United States are not defined as foreign companies and are not subject to this limitation.
The Fund may invest in initial public offerings (IPOs).
While the Fund primarily invests in value companies, it may also invest in growth companies if the Advisor believes that current valuation is at a sufficient discount to the projected long term earnings growth rate.
We use a “bottom up” process of fundamental analysis to look for individual companies that we believe are temporarily undervalued but have significant potential for stock price appreciation. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
We typically look for companies that we believe fall into one of these three categories at the time of purchase:

• Undiscovered Gems — Companies with good growth potential which have yet to be broadly discovered by Wall Street analysts, thus leaving them attractively undervalued relative to their expected growth.
• Fallen Angels — High quality growth companies that have experienced a temporary setback and therefore have appealing valuations relative to their long term growth potential.
• Value Momentum — Cheap valuation relative to history, but catalyst for future growth has been identified.
• The Fund may invest a large percentage of its assets in a few sectors, including financials, information technology, consumer discretionary, industrials, health care and materials.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap Company Stock Risk. Micro cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Value Investing Risk. Value investing attempts to identify strong companies whose stocks are selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic value may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH MICRO CAP VALUE FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/09	40.00%
Worst — 12/31/08	-26.67%

Average Annual Total Returns — (as of 12/31/12)

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Average Annual Total Returns Wasatch Micro Cap Value Fund	1 Year	5 Years	Since Inception	Inception Date
Investor Class	22.10%	3.40%	10.66%	Jul. 28, 2003
Return after taxes on distributions Investor Class	20.34%	3.07%	9.03%	Jul. 28, 2003
Return after taxes on distributions and sale of Fund shares Investor Class	16.67%	2.89%	8.74%	Jul. 28, 2003
Russell Microcap® Index (reflects no deductions for fees, expenses or taxes)	19.75%	1.46%	5.73%	Jul. 28, 2003

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 2.25% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). Acquired Fund Fees and Expenses are not included in the expense limitation. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date. The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund's most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

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Wasatch International Growth Fund

WASATCH INTERNATIONAL GROWTH FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Wasatch International Growth Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Wasatch International Growth Fund Investor Class Shares
Management Fee		1.25%
Distribution/Service (12b-1) Fee		none
Other Expenses		0.31%
Interest Expense		0.01%
Total Annual Fund Operating Expenses	[1]	1.57%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Wasatch International Growth Fund Investor Class	160	496	856	1,868

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 44% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in foreign growth companies.
Under normal market conditions, we will invest the Fund’s assets in the equity securities of foreign companies with market capitalizations of less than US$5 billion at the time of purchase. Under normal market conditions, the Fund will invest in at least five of the countries included in the Morgan Stanley Capital International (MSCI) All Country (AC) World Ex-U.S.A. Small Cap Index.
The Fund may invest a significant amount of its total assets (5% to 70% under normal market conditions) at the time of purchase in securities issued by companies domiciled in emerging markets. Emerging market countries are those currently included in the MSCI EFM (Emerging + Frontier Markets) Index. These companies typically are located in the Asia-Pacific region, Eastern Europe, the Middle East, Central and South America, and Africa.
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 may invest in early stage companies if we believe they have outstanding long-term 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 in a few sectors, including consumer discretionary, financials, industrials, information technology, materials, consumer staples, health care and energy.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH INTERNATIONAL GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns*

Best — 6/30/09	41.88%
Worst — 9/30/08	-28.61%

^[1]

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Wasatch International Growth Fund		1 Year	5 Years	10 Years
Investor Class		33.08%	3.52%	13.32%
Investor Class Return after taxes on distributions		33.01%	3.48%	12.68%
Investor Class Return after taxes on distributions and sale of Fund shares		21.60%	3.00%	11.83%
MSCI AC World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)	[1]	18.52%	(0.39%)	13.16%
MSCI World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)	[1]	17.48%	(0.70%)	12.04%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.75% until at least January 31, 2014 (excluding interest, interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). There were no reimbursements for the Investor Class shares of the Fund during 2012. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

[1] Prior to January 31, 2007, the Fund primarily invested in companies with market capitalizations of less than US$2 billion at the time of purchase.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Investor Class | Wasatch Small Cap Value Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH SMALL CAP VALUE FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 55% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

55.00%

Expenses Restated to Reflect Current [Text]

rr_ExpensesRestatedToReflectCurrent

The Fund’s operating expenses have been restated to reflect a reduction in the management fee, effective January 31, 2012, as if such changes had been in effect during the fiscal year ended September 30, 2012. The information has been restated to better reflect anticipated expenses of the Fund.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in small companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets in the equity securities of small companies with market capitalizations of less than $2.5 billion at the time of purchase.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly traded in the United States are not defined as foreign companies and are not subject to this limitation.
The Fund may also invest in growth companies if the Advisor believes that current valuation is at a sufficient discount to the projected long-term earnings growth rate.
We use a “bottom-up” process of fundamental analysis to look for individual companies that we believe are temporarily undervalued but have significant potential for stock price appreciation. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
We typically look for companies that we believe fall into one of these three categories at the time of purchase:

• Undiscovered Gems — Companies with good growth potential which have yet to be broadly discovered by Wall Street analysts, thus leaving them attractively undervalued relative to their expected growth.
• Fallen Angels — High quality growth companies that have experienced a temporary setback and therefore have appealing valuations relative to their long term growth potential.
• Quality Value — Quality companies with earnings potential that is not fully reflected in their stock prices.

The Fund may invest a large percentage of its assets in a few sectors, including industrials, information technology, financials, consumer discretionary, health care and energy.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Value Investing Risk. Value investing attempts to identify strong companies whose stocks are selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide information on how the Investor Class of the Fund has performed over time.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH SMALL CAP VALUE FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/09	33.91%
Worst — 12/31/08	-34.04%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Investor Class | Wasatch Small Cap Value Fund | Investor Class shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

(2.00%)

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.00%

^[1]

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Other Expenses

rr_OtherExpensesOverAssets

0.29%

^[1]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.29%

^[1],[2]

1 Year

rr_ExpenseExampleYear01

131

3 Years

rr_ExpenseExampleYear03

408

5 Years

rr_ExpenseExampleYear05

707

10 Years

rr_ExpenseExampleYear10

1,556

2003

rr_AnnualReturn2003

54.57%

2004

rr_AnnualReturn2004

21.58%

2005

rr_AnnualReturn2005

4.76%

2006

rr_AnnualReturn2006

14.84%

2007

rr_AnnualReturn2007

(3.00%)

2008

rr_AnnualReturn2008

(47.75%)

2009

rr_AnnualReturn2009

55.91%

2010

rr_AnnualReturn2010

25.52%

2011

rr_AnnualReturn2011

(5.22%)

2012

rr_AnnualReturn2012

16.52%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

33.91%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(34.04%)

1 Year

rr_AverageAnnualReturnYear01

16.52%

5 Years

rr_AverageAnnualReturnYear05

2.46%

10 Years

rr_AverageAnnualReturnYear10

9.49%

Investor Class | Wasatch Small Cap Value Fund | Return after taxes on distributions | Investor Class shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

16.52%

5 Years

rr_AverageAnnualReturnYear05

2.46%

10 Years

rr_AverageAnnualReturnYear10

8.05%

Investor Class | Wasatch Small Cap Value Fund | Return after taxes on distributions and sale of Fund shares | Investor Class shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

10.74%

5 Years

rr_AverageAnnualReturnYear05

2.11%

10 Years

rr_AverageAnnualReturnYear10

7.96%

Investor Class | Wasatch Small Cap Value Fund | Russell 2000® Value Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

18.05%

5 Years

rr_AverageAnnualReturnYear05

3.55%

10 Years

rr_AverageAnnualReturnYear10

9.50%

Investor Class | Wasatch Small Cap Value Fund | Russell 2000® Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

16.35%

5 Years

rr_AverageAnnualReturnYear05

3.56%

10 Years

rr_AverageAnnualReturnYear10

9.72%

[1] The Fund's operating expenses have been restated to reflect a reduction in the management fee, effective January 31, 2012, as if such changes had been in effect during the fiscal year ended September 30, 2012. The information has been restated to better reflect anticipated expenses of the Fund.

[2] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date. There were no reimbursements for the Investor Class shares of the Fund during 2012.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Institutional Class | Wasatch Small Cap Value Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH SMALL CAP VALUE FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 55% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

55.00%

Expenses Restated to Reflect Current [Text]

rr_ExpensesRestatedToReflectCurrent

The Fund’s operating expenses have been restated to reflect a reduction in the management fee, effective January 31, 2012, as if such changes had been in effect during the fiscal year ended September 30, 2012. The information has been restated to better reflect anticipated expenses of the Fund.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in small companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets in the equity securities of small companies with market capitalizations of less than $2.5 billion at the time of purchase.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly traded in the United States are not defined as foreign companies and are not subject to this limitation.
The Fund may also invest in growth companies if the Advisor believes that current valuation is at a sufficient discount to the projected long-term earnings growth rate.
We use a “bottom-up” process of fundamental analysis to look for individual companies that we believe are temporarily undervalued but have significant potential for stock price appreciation. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
We typically look for companies that we believe fall into one of these three categories at the time of purchase:

• Undiscovered Gems — Companies with good growth potential which have yet to be broadly discovered by Wall Street analysts, thus leaving them attractively undervalued relative to their expected growth.
• Fallen Angels — High quality growth companies that have experienced a temporary setback and therefore have appealing valuations relative to their long term growth potential.
• Quality Value — Quality companies with earnings potential that is not fully reflected in their stock prices.

The Fund may invest a large percentage of its assets in a few sectors, including industrials, information technology, financials, consumer discretionary, health care and energy.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Value Investing Risk. Value investing attempts to identify strong companies whose stocks are selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Fund has performed over time. The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. The Fund’s Institutional Class commenced operations on January 31, 2012. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide information on how the Fund has performed over time.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH SMALL CAP VALUE FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/09	33.91%
Worst — 12/31/08	-34.04%

Bar Chart, Returns for Class Not Offered in Prospectus [Text]

rr_BarChartReturnsForClassNotOfferedInProspectus

The Fund’s Institutional Class commenced operations on January 31, 2012. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses.

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Institutional Class | Wasatch Small Cap Value Fund | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.00%

^[1]

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Other Expenses

rr_OtherExpensesOverAssets

0.66%

^[1]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.66%

^[1],[2]

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.51%)

^[1]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.15%

^[1]

1 Year

rr_ExpenseExampleYear01

117

3 Years

rr_ExpenseExampleYear03

473

5 Years

rr_ExpenseExampleYear05

853

10 Years

rr_ExpenseExampleYear10

1,922

Institutional Class | Wasatch Small Cap Value Fund | Investor Class shares

Risk/Return:

rr_RiskReturnAbstract

2003

rr_AnnualReturn2003

54.57%

2004

rr_AnnualReturn2004

21.58%

2005

rr_AnnualReturn2005

4.76%

2006

rr_AnnualReturn2006

14.84%

2007

rr_AnnualReturn2007

(3.00%)

2008

rr_AnnualReturn2008

(47.75%)

2009

rr_AnnualReturn2009

55.91%

2010

rr_AnnualReturn2010

25.52%

2011

rr_AnnualReturn2011

(5.22%)

2012

rr_AnnualReturn2012

16.52%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

33.91%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(34.04%)

1 Year

rr_AverageAnnualReturnYear01

16.52%

5 Years

rr_AverageAnnualReturnYear05

2.46%

10 Years

rr_AverageAnnualReturnYear10

9.49%

Institutional Class | Wasatch Small Cap Value Fund | Return after taxes on distributions | Investor Class shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

16.52%

5 Years

rr_AverageAnnualReturnYear05

2.46%

10 Years

rr_AverageAnnualReturnYear10

8.05%

Institutional Class | Wasatch Small Cap Value Fund | Return after taxes on distributions and sale of Fund shares | Investor Class shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

10.74%

5 Years

rr_AverageAnnualReturnYear05

2.11%

10 Years

rr_AverageAnnualReturnYear10

7.96%

Institutional Class | Wasatch Small Cap Value Fund | Russell 2000® Value Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

18.05%

5 Years

rr_AverageAnnualReturnYear05

3.55%

10 Years

rr_AverageAnnualReturnYear10

9.50%

Institutional Class | Wasatch Small Cap Value Fund | Russell 2000® Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

16.35%

5 Years

rr_AverageAnnualReturnYear05

3.56%

10 Years

rr_AverageAnnualReturnYear10

9.72%

[1] The Fund's operating expenses have been restated to reflect a reduction in the management fee, effective January 31, 2012, as if such changes had been in effect during the fiscal year ended September 30, 2012. The information has been restated to better reflect anticipated expenses of the Fund.

[2] The Advisor has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.15% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Wasatch Ultra Growth Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH ULTRA GROWTH FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s primary investment objective is long-term growth of capital.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 43% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

43.00%

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees

The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund’s most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in smaller high growth companies.
Under normal market conditions, we will invest the Fund’s assets in the equity securities of rapidly growing companies. These companies are usually small to mid-size with market capitalizations of less than $5 billion at the time of purchase.
The Fund may invest up to 30% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly traded in the United States are not defined as foreign companies and are not subject to this limitation.
We use a process of “bottom up” fundamental analysis to look for individual companies that we believe have above average potential for rapid earnings growth and stock price appreciation. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
The Fund may invest a large percentage of its assets in a few sectors, including information technology, financials, health care, consumer discretionary and industrials.
The Fund may invest in initial public offerings (IPOs).

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide information on how the Investor Class of the Fund has performed over time.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com.

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH ULTRA GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/03	29.29%
Worst — 12/31/08	-31.56%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch Ultra Growth Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.00%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.32%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.20%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.52%

^[1]

1 Year

rr_ExpenseExampleYear01

155

3 Years

rr_ExpenseExampleYear03

481

5 Years

rr_ExpenseExampleYear05

831

10 Years

rr_ExpenseExampleYear10

1,817

2003

rr_AnnualReturn2003

44.52%

2004

rr_AnnualReturn2004

(0.82%)

2005

rr_AnnualReturn2005

3.58%

2006

rr_AnnualReturn2006

7.31%

2007

rr_AnnualReturn2007

15.11%

2008

rr_AnnualReturn2008

(55.40%)

2009

rr_AnnualReturn2009

55.01%

2010

rr_AnnualReturn2010

35.85%

2011

rr_AnnualReturn2011

(5.37%)

2012

rr_AnnualReturn2012

12.45%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2003

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

29.29%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(31.56%)

1 Year

rr_AverageAnnualReturnYear01

12.45%

5 Years

rr_AverageAnnualReturnYear05

(0.01%)

10 Years

rr_AverageAnnualReturnYear10

6.25%

Wasatch Ultra Growth Fund | Return after taxes on distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

10.16%

5 Years

rr_AverageAnnualReturnYear05

(0.59%)

10 Years

rr_AverageAnnualReturnYear10

5.21%

Wasatch Ultra Growth Fund | Return after taxes on distributions and sale of Fund shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

11.10%

5 Years

rr_AverageAnnualReturnYear05

(0.03%)

10 Years

rr_AverageAnnualReturnYear10

5.29%

Wasatch Ultra Growth Fund | Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

14.59%

5 Years

rr_AverageAnnualReturnYear05

3.49%

10 Years

rr_AverageAnnualReturnYear10

9.80%

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). Acquired Fund Fees and Expenses are not included in the expense limitation. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date. There were no reimbursements for the Investor Class shares of the Fund during 2012. The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund's most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Institutional Class | Wasatch Large Cap Value Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH LARGE CAP VALUE FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objectives are to seek capital appreciation and income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 14% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

14.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in equity securities.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets in equity securities (including common stock, preferred stock and securities convertible into common stocks) of companies with market capitalizations of over $5 billion at the time of purchase.
The Fund typically invests in the securities of companies that we believe will pay above average dividends or interest.
When evaluating a potential investment for the Fund, we employ a comprehensive valuation analysis intended to establish a range for fair valuation or intrinsic company value, with a particular emphasis on company fundamentals. The initial valuation review may include:

• Calculating and reviewing standard ratios such as price-to-sales, price-to-book, price-to-earnings, and price/earnings-to-growth.
• Modified discounted cash flow models with sensitivity analysis for changes to revenue growth rates, operating margins, outstanding share counts, earnings multiples, and tangible book value.
• Changing sector and company specific outlooks due to subjective factors, including globalization of capital, labor and process knowledge, as well as increasing information and price transparency.

The Fund may invest a large percentage of its assets in a few sectors, including energy, financials, information technology, consumer staples, health care and industrials.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Value Investing Risk. Value investing attempts to identify strong companies whose stocks are selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Fund’s Investor Class shares commenced operations on December 15, 2008 upon the reorganization of the 1st Source Monogram Income Equity Fund, the Fund’s predecessor fund (the “Predecessor Fund”), into the Fund. With the reorganization, the Fund assumed the financial and performance history of the Predecessor Fund. The following tables provide an indication of the historical risk of an investment in the Fund (and Predecessor Fund for periods prior to December 15, 2008). The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to that of a broad-based market index. Past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. In addition, the Predecessor Fund was advised by a different investment advisor and subject to different expenses, which may have produced different investment results. The Fund, however, has two portfolio managers, one of which was also the portfolio manager of the Predecessor Fund. The Fund’s Institutional Class commenced operations on January 31, 2012. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide an indication of the historical risk of an investment in the Fund (and Predecessor Fund for periods prior to December 15, 2008). The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to that of a broad-based market index.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH LARGE CAP VALUE FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/03	15.78%
Worst — 12/31/08	-19.38%

Bar Chart, Returns for Class Not Offered in Prospectus [Text]

rr_BarChartReturnsForClassNotOfferedInProspectus

The Fund’s Institutional Class commenced operations on January 31, 2012. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses.

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Institutional Class | Wasatch Large Cap Value Fund | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

0.90%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.41%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.31%

^[1]

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.33%)

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

0.98%

1 Year

rr_ExpenseExampleYear01

100

3 Years

rr_ExpenseExampleYear03

383

5 Years

rr_ExpenseExampleYear05

687

10 Years

rr_ExpenseExampleYear10

1,550

Institutional Class | Wasatch Large Cap Value Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

2003

rr_AnnualReturn2003

29.85%

2004

rr_AnnualReturn2004

17.01%

2005

rr_AnnualReturn2005

9.94%

2006

rr_AnnualReturn2006

20.02%

2007

rr_AnnualReturn2007

12.36%

2008

rr_AnnualReturn2008

(31.14%)

2009

rr_AnnualReturn2009

24.37%

2010

rr_AnnualReturn2010

11.11%

2011

rr_AnnualReturn2011

(3.92%)

2012

rr_AnnualReturn2012

10.55%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2003

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

15.78%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(19.38%)

1 Year

rr_AverageAnnualReturnYear01

10.55%

5 Years

rr_AverageAnnualReturnYear05

0.22%

10 Years

rr_AverageAnnualReturnYear10

8.58%

Institutional Class | Wasatch Large Cap Value Fund | Return after taxes on distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

10.17%

5 Years

rr_AverageAnnualReturnYear05

(0.18%)

10 Years

rr_AverageAnnualReturnYear10

7.64%

Institutional Class | Wasatch Large Cap Value Fund | Return after taxes on distributions and sale of Fund shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

7.35%

5 Years

rr_AverageAnnualReturnYear05

0.02%

10 Years

rr_AverageAnnualReturnYear10

7.23%

Institutional Class | Wasatch Large Cap Value Fund | Russell 1000® Value Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

17.51%

5 Years

rr_AverageAnnualReturnYear05

0.59%

10 Years

rr_AverageAnnualReturnYear10

7.38%

[1] The Advisor has contractually agreed to reimburse Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 0.98% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

XML

Investor Class | Wasatch Emerging Markets Select Fund

WASATCH EMERGING MARKETS SELECT FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Investor Class Wasatch Emerging Markets Select Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Investor Class Wasatch Emerging Markets Select Fund Investor Class Shares
Management Fee		1.25%
Distribution/Service (12b-1) Fee		none
Other Expenses	[1]	1.02%
Total Annual Fund Operating Expenses	[1]	2.27%
Expense Reimbursement		(0.58%)
Total Annual Fund Operating Expenses After Expense Reimbursement		1.69%

EXAMPLE

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the Fund’s operating expenses (as a percentage of net assets) remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years
Investor Class Wasatch Emerging Markets Select Fund Investor Class Shares	172	654

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance.

PRINCIPAL STRATEGIES

The Fund invests primarily in companies of all market capitalizations that are tied economically to emerging market countries.
Under normal market conditions, we will invest at least 80% of the Fund’s assets in the equity securities (including common stock, preferred stock and securities convertible into common stock) of companies that are tied economically to emerging market countries.
Emerging market countries are those currently included in the Morgan Stanley Capital International (MSCI) Emerging Markets Index. We will generally 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 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 with the goal of owning the highest quality growth companies tied economically to emerging market countries. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
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 in a few sectors.
The Fund may invest in initial public offerings (IPOs) and early stage companies.
The Fund is non-diversified, meaning that it can concentrate investments in a more limited number of issuers than a diversified fund. Under normal market conditions, the Fund will generally invest in 30 to 50 companies; however, we may invest in fewer or more companies when we believe it is necessary to achieve the Fund’s investment objective.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Convertible Securities Risk. Generally, convertible securities offer lower interest or dividend yields than non-convertible securities of similar quality and less potential for gains or capital appreciation in a rising stock market than other equity securities. They tend to be more volatile than other fixed income securities, and the markets for convertible securities may be less liquid than the markets for common stocks or bonds. The value of convertible securities is susceptible to the risk of market losses attributable to changes in interest rates. An issuer may have the right to buy back certain convertible securities at a time and price that is unfavorable to the Fund.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Non-Diversification Risk. Because the Fund is non-diversified and generally invests in 30 to 50 companies, the Fund will have more exposure to the price movements of a single security or a small group of securities than funds that diversify their investments among many companies. The Fund’s total return and net asset value could fluctuate more than if a greater number of securities were held.

PERFORMANCE

Ordinarily, this section of the prospectus contains information that would allow you to evaluate the performance of the Fund’s Investor Class using several different measures such as yearly changes in performance, best and worst quarterly returns and average annual total returns before and after taxes compared to a relevant benchmark. However, the Wasatch Emerging Markets Select Fund has only recently commenced operations and does not have a full calendar year of performance.

[1] Other Expenses are based on estimated expenses for the Investor Class of the Fund for its first full fiscal year. The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.69% (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses in excess of such limitations) until at least January 31, 2014. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Institutional Class | Wasatch Core Growth Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH CORE GROWTH FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s primary investment objective is long-term growth of capital.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 28% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

28.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in smaller growing companies at reasonable prices.
Under normal market conditions, we will invest at least 65% of the Fund’s net assets in the equity securities of growing companies. These companies are usually small to mid-size with market capitalizations of less than $5 billion at the time of purchase.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly 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 individual companies that we believe are stable and have the potential to grow steadily for long periods of time. 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 may invest a large percentage of its assets in a few sectors, including industrials, financials, consumer discretionary, information technology and health care.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small and mid cap stocks may be very sensitive to changing economic conditions and market downturns.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Fund has performed over time. The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total returns table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index, and an additional index composed of securities similar to those held by the Fund. The Fund’s Institutional Class commenced operations on January 31, 2012. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide information on how the Fund has performed over time.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH CORE GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/09	29.50%
Worst — 12/31/08	-27.03%

Bar Chart, Returns for Class Not Offered in Prospectus [Text]

rr_BarChartReturnsForClassNotOfferedInProspectus

The Fund’s Institutional Class commenced operations on January 31, 2012. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses.

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Institutional Class | Wasatch Core Growth Fund | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.00%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.55%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.55%

^[1]

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.43%)

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.12%

1 Year

rr_ExpenseExampleYear01

114

3 Years

rr_ExpenseExampleYear03

447

5 Years

rr_ExpenseExampleYear05

803

10 Years

rr_ExpenseExampleYear10

1,809

Institutional Class | Wasatch Core Growth Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

2003

rr_AnnualReturn2003

38.46%

2004

rr_AnnualReturn2004

21.65%

2005

rr_AnnualReturn2005

3.26%

2006

rr_AnnualReturn2006

6.68%

2007

rr_AnnualReturn2007

6.40%

2008

rr_AnnualReturn2008

(44.34%)

2009

rr_AnnualReturn2009

45.16%

2010

rr_AnnualReturn2010

24.99%

2011

rr_AnnualReturn2011

5.09%

2012

rr_AnnualReturn2012

19.19%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

29.50%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(27.03%)

1 Year

rr_AverageAnnualReturnYear01

19.19%

5 Years

rr_AverageAnnualReturnYear05

4.81%

10 Years

rr_AverageAnnualReturnYear10

9.58%

Institutional Class | Wasatch Core Growth Fund | Return after taxes on distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

19.19%

5 Years

rr_AverageAnnualReturnYear05

4.71%

10 Years

rr_AverageAnnualReturnYear10

8.80%

Institutional Class | Wasatch Core Growth Fund | Return after taxes on distributions and sale of Fund shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.48%

5 Years

rr_AverageAnnualReturnYear05

4.07%

10 Years

rr_AverageAnnualReturnYear10

8.28%

Institutional Class | Wasatch Core Growth Fund | Russell 2000® Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

16.35%

5 Years

rr_AverageAnnualReturnYear05

3.56%

10 Years

rr_AverageAnnualReturnYear10

9.72%

Institutional Class | Wasatch Core Growth Fund | Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

14.59%

5 Years

rr_AverageAnnualReturnYear05

3.49%

10 Years

rr_AverageAnnualReturnYear10

9.80%

[1] The Advisor has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.12% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Investor Class | Wasatch Large Cap Value Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH LARGE CAP VALUE FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVES

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objectives are to seek capital appreciation and income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 14% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

14.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in equity securities.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets in equity securities (including common stock, preferred stock and securities convertible into common stock) of companies with market capitalizations of over $5 billion at the time of purchase.
The Fund typically invests in the securities of companies that we believe will pay above average dividends or interest.
When evaluating a potential investment for the Fund, we employ a comprehensive valuation analysis intended to establish a range for fair valuation or intrinsic company value, with a particular emphasis on company fundamentals. The initial valuation review may include:

• Calculating and reviewing standard ratios, such as price-to-sales, price-to-book, price-to-earnings, and price/earnings-to-growth.
• Modified discounted cash flow models with sensitivity analysis for changes to revenue growth rates, operating margins, outstanding share counts, earnings multiples, and tangible book value.
• Changing sector and company specific outlooks due to subjective factors, including globalization of capital, labor and process knowledge, as well as increasing information and price transparency.

The Fund may invest a large percentage of its assets in a few sectors, including energy, financials, information technology, consumer staples, health care and industrials.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Value Investing Risk. Value investing attempts to identify strong companies whose stocks are selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Fund commenced operations on December 15, 2008 upon the reorganization of the 1st Source Monogram Income Equity Fund, the Fund’s predecessor fund (the “Predecessor Fund”), into the Fund. With the reorganization, the Fund assumed the financial and performance history of the Predecessor Fund. The following tables provide an indication of the historical risk of an investment in the Fund (and Predecessor Fund for periods prior to December 15, 2008). The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to that of a broad-based market index. Past performance, before and after taxes, is not necessarily an indication of how the Investor Class of the Fund will perform in the future. In addition, the Predecessor Fund was advised by a different investment advisor and subject to different expenses, which may have produced different investment results. The Fund, however, has two portfolio managers, one of which was also the portfolio manager of the Predecessor Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide an indication of the historical risk of an investment in the Fund (and Predecessor Fund for periods prior to December 15, 2008). The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to that of a broad-based market index.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Past performance, before and after taxes, is not necessarily an indication of how the Investor Class of the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH LARGE CAP VALUE FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/03	15.78%
Worst — 12/31/08	-19.38%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Investor Class | Wasatch Large Cap Value Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

0.90%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.25%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.15%

^[1]

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.05%)

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.10%

1 Year

rr_ExpenseExampleYear01

112

3 Years

rr_ExpenseExampleYear03

360

5 Years

rr_ExpenseExampleYear05

627

10 Years

rr_ExpenseExampleYear10

1,393

2003

rr_AnnualReturn2003

29.85%

2004

rr_AnnualReturn2004

17.01%

2005

rr_AnnualReturn2005

9.94%

2006

rr_AnnualReturn2006

20.02%

2007

rr_AnnualReturn2007

12.36%

2008

rr_AnnualReturn2008

(31.14%)

2009

rr_AnnualReturn2009

24.37%

2010

rr_AnnualReturn2010

11.11%

2011

rr_AnnualReturn2011

(3.92%)

2012

rr_AnnualReturn2012

10.55%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2003

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

15.78%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(19.38%)

1 Year

rr_AverageAnnualReturnYear01

10.55%

5 Years

rr_AverageAnnualReturnYear05

0.22%

10 Years

rr_AverageAnnualReturnYear10

8.58%

Investor Class | Wasatch Large Cap Value Fund | Return after taxes on distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

10.17%

5 Years

rr_AverageAnnualReturnYear05

(0.18%)

10 Years

rr_AverageAnnualReturnYear10

7.64%

Investor Class | Wasatch Large Cap Value Fund | Return after taxes on distributions and sale of Fund shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

7.35%

5 Years

rr_AverageAnnualReturnYear05

0.02%

10 Years

rr_AverageAnnualReturnYear10

7.23%

Investor Class | Wasatch Large Cap Value Fund | Russell 1000® Value Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

17.51%

5 Years

rr_AverageAnnualReturnYear05

0.59%

10 Years

rr_AverageAnnualReturnYear10

7.38%

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.10% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

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Wasatch Global Opportunities Fund

WASATCH GLOBAL OPPORTUNITIES FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Wasatch Global Opportunities Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Wasatch Global Opportunities Fund Investor Class Shares
Management Fee		1.50%
Distribution/Service (12b-1) Fee		none
Other Expenses		0.34%
Total Annual Fund Operating Expenses	[1]	1.84%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Wasatch Global Opportunities Fund Investor Class	187	579	996	2,158

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 38% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in small and micro cap foreign and domestic companies.
Under normal market conditions, we will invest the Fund’s assets in equity securities (including common stock, preferred stock and securities convertible into common stock) of foreign and domestic companies with market capitalizations of less than US$5 billion at the time of purchase. The Fund may invest a significant portion of its total assets (up to 35% under normal market conditions) in securities of companies with market capitalizations greater than US$5 billion at the time of purchase when the companies meet our investment criteria. The Fund may also invest a significant portion of its total assets in micro cap companies with market capitalizations below US$1 billion (up to 90% under normal market conditions).
The Fund will typically invest in securities issued by companies domiciled in at least three countries, including the United States. The Fund may invest a significant portion of its total assets in companies domiciled in foreign countries (up to 80% under normal market conditions). Securities issued by foreign companies incorporated outside the United States whose securities are publicly traded in the United States are not defined as “foreign companies” and are not subject to this limitation.
The Fund may invest a significant amount of its total assets (5% to 50% under normal market conditions) at the time of purchase in securities issued by companies domiciled in emerging markets. Emerging market countries are those currently included in the Morgan Stanley Capital International (MSCI) EFM (Emerging + Frontier Markets) Index. These companies typically are located in the Asia-Pacific region, Eastern Europe, the Middle East, Central and South America, and Africa.
We use a process of quantitative screening followed by “bottom up” fundamental analysis to identify individual companies that we believe are the World’s Best Growth Companies.^® We travel extensively to visit companies and expect to meet with senior management.
We may also invest in growth companies that we believe have had a temporary setback and therefore have appealing valuation relative to their long-term growth potential.
At times, we may invest in early stage companies with limited or no earnings history if we believe they have outstanding long-term growth potential. We may also invest in initial public offerings (IPOs).
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries. We may significantly shift Fund assets between asset classes, sectors, and geographic regions based on where we believe the best growth opportunities and valuations currently exist. The Fund may invest a large percentage of its assets in a few regions or sectors, including industrials, information technology, consumer discretionary, health care, financials, materials and energy.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Region Risk. Social, political and economic conditions and changes in regulatory, tax, or economic policy in a country or region could significantly affect the market in that country or region. In addition, global economies and financial markets are becoming increasingly interconnected, which increases the possibility that conditions in one country or region might adversely impact the issuers of securities in a different country or region. From time to time, a small number of companies and industries may represent a large portion of the market in a particular country or region, and these companies and industries can be sensitive to adverse social, political, economic, or regulatory developments.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap and Small Company Stock Risk. Micro cap and small company stocks may be very sensitive to changing economic conditions and market downturns.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Value Investing Risk. Value investing attempts to identify strong companies whose stocks are selling at a discount from their perceived true worth, and is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH GLOBAL OPPORTUNITIES FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/09	32.73%
Worst — 9/30/11	-18.94%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Wasatch Global Opportunities Fund		1 Year	Since Inception	Inception Date
Investor Class		25.50%	26.07%	Nov. 17, 2008
Investor Class Return after taxes on distributions		23.40%	24.64%	Nov. 17, 2008
Investor Class Return after taxes on distributions and sale of Fund shares		19.34%	22.83%	Nov. 17, 2008
MSCI All Country (AC) World Small Cap Index (reflects no deductions for fees, expenses or taxes)	[1]	18.06%	20.34%	Nov. 17, 2008
S&P Global SmallCap Index (reflects no deductions for fees, expenses or taxes)		19.08%	19.44%	Nov. 17, 2008

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.95% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). There were no reimbursements for the Investor Class shares of the Fund during 2012. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

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Investor Class | Wasatch Large Cap Value Fund

WASATCH LARGE CAP VALUE FUND — Summary

INVESTMENT OBJECTIVES

The Fund’s investment objectives are to seek capital appreciation and income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Investor Class Wasatch Large Cap Value Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Investor Class Wasatch Large Cap Value Fund Investor Class Shares
Management Fee		0.90%
Distribution/Service (12b-1) Fee		none
Other Expenses		0.25%
Total Annual Fund Operating Expenses	[1]	1.15%
Expense Reimbursement		(0.05%)
Total Annual Fund Operating Expenses After Expense Reimbursement		1.10%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Investor Class Wasatch Large Cap Value Fund	112	360	627	1,393

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 14% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in equity securities.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets in equity securities (including common stock, preferred stock and securities convertible into common stock) of companies with market capitalizations of over $5 billion at the time of purchase.
The Fund typically invests in the securities of companies that we believe will pay above average dividends or interest.
When evaluating a potential investment for the Fund, we employ a comprehensive valuation analysis intended to establish a range for fair valuation or intrinsic company value, with a particular emphasis on company fundamentals. The initial valuation review may include:

• Calculating and reviewing standard ratios, such as price-to-sales, price-to-book, price-to-earnings, and price/earnings-to-growth.
• Modified discounted cash flow models with sensitivity analysis for changes to revenue growth rates, operating margins, outstanding share counts, earnings multiples, and tangible book value.
• Changing sector and company specific outlooks due to subjective factors, including globalization of capital, labor and process knowledge, as well as increasing information and price transparency.

The Fund may invest a large percentage of its assets in a few sectors, including energy, financials, information technology, consumer staples, health care and industrials.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Value Investing Risk. Value investing attempts to identify strong companies whose stocks are selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

HISTORICAL PERFORMANCE

The Fund commenced operations on December 15, 2008 upon the reorganization of the 1st Source Monogram Income Equity Fund, the Fund’s predecessor fund (the “Predecessor Fund”), into the Fund. With the reorganization, the Fund assumed the financial and performance history of the Predecessor Fund. The following tables provide an indication of the historical risk of an investment in the Fund (and Predecessor Fund for periods prior to December 15, 2008). The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to that of a broad-based market index. Past performance, before and after taxes, is not necessarily an indication of how the Investor Class of the Fund will perform in the future. In addition, the Predecessor Fund was advised by a different investment advisor and subject to different expenses, which may have produced different investment results. The Fund, however, has two portfolio managers, one of which was also the portfolio manager of the Predecessor Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH LARGE CAP VALUE FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/03	15.78%
Worst — 12/31/08	-19.38%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Investor Class	1 Year	5 Years	10 Years
Wasatch Large Cap Value Fund	10.55%	0.22%	8.58%
Wasatch Large Cap Value Fund Return after taxes on distributions	10.17%	(0.18%)	7.64%
Wasatch Large Cap Value Fund Return after taxes on distributions and sale of Fund shares	7.35%	0.02%	7.23%
Wasatch Large Cap Value Fund Russell 1000® Value Index (reflects no deductions for fees, expenses or taxes)	17.51%	0.59%	7.38%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.10% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Investor Class | Wasatch Core Growth Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH CORE GROWTH FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s primary investment objective is long-term growth of capital.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 28% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

28.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in smaller growing companies at reasonable prices.
Under normal market conditions, we will invest at least 65% of the Fund’s net assets in the equity securities of growing companies. These companies are usually small to mid-size with market capitalizations of less than $5 billion at the time of purchase.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly 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 individual companies that we believe are stable and have the potential to grow steadily for long periods of time. 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 may invest a large percentage of its assets in a few sectors, including industrials, financials, consumer discretionary, information technology and health care.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small and mid cap stocks may be very sensitive to changing economic conditions and market downturns.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide information on how the Investor Class of the Fund has performed over time.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH CORE GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/09	29.50%
Worst — 12/31/08	-27.03%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Investor Class | Wasatch Core Growth Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.00%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.23%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.23%

^[1]

1 Year

rr_ExpenseExampleYear01

125

3 Years

rr_ExpenseExampleYear03

390

5 Years

rr_ExpenseExampleYear05

675

10 Years

rr_ExpenseExampleYear10

1,487

2003

rr_AnnualReturn2003

38.46%

2004

rr_AnnualReturn2004

21.65%

2005

rr_AnnualReturn2005

3.26%

2006

rr_AnnualReturn2006

6.68%

2007

rr_AnnualReturn2007

6.40%

2008

rr_AnnualReturn2008

(44.34%)

2009

rr_AnnualReturn2009

45.16%

2010

rr_AnnualReturn2010

24.99%

2011

rr_AnnualReturn2011

5.09%

2012

rr_AnnualReturn2012

19.19%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

29.50%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(27.03%)

1 Year

rr_AverageAnnualReturnYear01

19.19%

5 Years

rr_AverageAnnualReturnYear05

4.81%

10 Years

rr_AverageAnnualReturnYear10

9.58%

Investor Class | Wasatch Core Growth Fund | Return after taxes on distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

19.19%

5 Years

rr_AverageAnnualReturnYear05

4.71%

10 Years

rr_AverageAnnualReturnYear10

8.80%

Investor Class | Wasatch Core Growth Fund | Return after taxes on distributions and sale of Fund shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.48%

5 Years

rr_AverageAnnualReturnYear05

4.07%

10 Years

rr_AverageAnnualReturnYear10

8.28%

Investor Class | Wasatch Core Growth Fund | Russell 2000® Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

16.35%

5 Years

rr_AverageAnnualReturnYear05

3.56%

10 Years

rr_AverageAnnualReturnYear10

9.72%

Investor Class | Wasatch Core Growth Fund | Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

14.59%

5 Years

rr_AverageAnnualReturnYear05

3.49%

10 Years

rr_AverageAnnualReturnYear10

9.80%

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date. There were no reimbursements for the Investor Class shares of the Fund during 2012.

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Institutional Class | Wasatch Long/Short Fund

WASATCH LONG/SHORT FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s investment objective is capital appreciation.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Institutional Class Wasatch Long/Short Fund Institutional Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Institutional Class Wasatch Long/Short Fund Institutional Class Shares
Management Fee		1.10%
Distribution/Service (12b-1) Fee		none
Dividend Expense on Short Sales/Interest Expense	[1]	0.24%
Other Expenses	[2]	0.10%
Total Annual Fund Operating Expenses	[2]	1.44%
Expense Reimbursement		(0.03%)
Total Annual Fund Operating Expenses After Expense Reimbursement		1.41%

EXAMPLE

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the Fund’s operating expenses (as a percentage of net assets) remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Institutional Class Wasatch Long/Short Fund	144	453	785	1,723

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 71% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in equity securities by maintaining long equity positions and short equity positions.
We seek to achieve higher risk-adjusted returns with lower volatility compared to the equity markets in general (as represented by the S&P 500 Index). Under normal market conditions, we will invest the Fund’s assets in the equity securities of companies with market capitalizations of at least $100 million at the time of purchase that we have identified as being undervalued (long equity positions) and we will sell short those securities (short equity positions) that we have identified as being overvalued. The equity securities in which the Fund invests include common stocks, preferred stocks, securities convertible into or exchangeable for common stocks, warrants and any rights to purchase common stocks.
The Fund may at any time have either a net long exposure or a net short exposure to the equity markets and the Fund will not be managed to maintain either net long or net short market exposure.
The Fund may invest in early stage companies and initial public offerings (IPOs).
We believe that the best opportunities to make both short and long equity investments are when the market’s perception of the values of individual companies (measured by the stock price) differs widely from our assessment of the intrinsic values of such companies. We further believe that opportunities to invest in undervalued and overvalued stocks arise due to a variety of market inefficiencies including:

• Changes in market participant psychology and circumstances.
• Imperfect information.
• Forecasts and projections by Wall Street analysts and company representatives that differ from experienced reality.
  When evaluating a potential long or short investment for the Fund, we employ a comprehensive valuation analysis intended to establish a range for fair valuation or intrinsic company value, with particular emphasis on company fundamentals.
  Along with long positions, the Long/Short Fund intends to engage in short sales of securities of companies that we believe:
• Have earnings that appear to be reflected in the current price.
• Are likely to fall short of market expectations.
• Are in industries exhibiting weaknesses.
• Have poor management.
• Are likely to suffer an event affecting long-term earnings.
  The Fund may invest in fixed income securities of any maturity consisting of corporate notes, bonds and debentures, including those that are rated less than investment grade at the time of purchase.
  The Fund is non-diversified, meaning that it can concentrate investments in a more limited number of issuers than a diversified fund.
  The Fund may invest a large percentage of its assets in a few sectors, including information technology, financials, energy, consumer discretionary, materials, industrials and consumer staples.
  The Fund is expected to have a high portfolio turnover rate.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Market Direction Risk. Since the Fund has both a “long” and a “short” portfolio, an investment in the Fund will involve market risks associated with different types of investment decisions than those made for a typical “long only” stock fund. The Fund’s results will suffer both when there is a general stock market advance and the Fund holds significant “short” equity positions, or when there is a general stock market decline and the Fund holds significant “long” equity positions.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Short Sales Risk. The Fund may make short sales of securities, which means it may experience a loss if the market price of the security increases between the date of the short sale and the date the security is replaced. Short sales may reduce the Fund’s returns or increase volatility.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Non-Diversification Risk. The Fund can invest a larger portion of its assets in the stocks of a limited number of companies than a diversified fund, which means it may have more exposure to the price movements of a single security or small group of securities than funds that diversify their investments among many companies.
Value Investing Risk. Value investing attempts to identify strong companies whose stocks are selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Interest Rate Risk. Interest rate risk is the risk that a debt security’s value will decline due to changes in market interest rates. Even though some interest-bearing securities offer a stable stream of income, their prices will fluctuate with changes in interest rates.
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. Credit risk is affected by the issuer’s credit status, and is generally higher for non-investment grade securities.
Non-Investment Grade Securities Risk. Non-investment grade securities (also known as “junk bonds”), those rated below investment grade by the primary rating agencies (e.g., below BB/Ba by S&P/Moody’s), tend to have more volatile prices and increased price sensitivity to changing interest rates and adverse economic and business developments than investment grade securities. In addition, compared to investments in investment grade securities, investments in non-investment grade securities are subject to greater risk of loss due to default or decline in credit quality. There is a greater likelihood that adverse economic or company-specific events will make the issuer unable to make interest and/or principal payments, and more susceptible to negative market sentiment, leading to depressed prices and decreased liquidity.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in price and supply of energy fuels, energy conservation, supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Information Technology Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Portfolio Turnover Rate. The Fund’s portfolio turnover rate is expected to exceed 200%. This type of Fund has a high portfolio turnover that necessarily results in greater transaction costs and causes more short-term capital gains (or losses) to be realized. Distributions to shareholders of short-term capital gains are taxed as ordinary income under federal income tax laws.

HISTORICAL PERFORMANCE

The Fund’s Investor Class shares commenced operations on December 15, 2008, upon the reorganization of the 1st Source Monogram Long/Short Fund, the Fund’s predecessor fund (the “Predecessor Fund”), into the Fund. With the reorganization, the Fund assumed the financial and performance history of the Predecessor Fund. The following tables provide an indication of the historical risk of an investment in the Fund (and Predecessor Fund for periods prior to December 15, 2008) as represented by the Fund’s Investor Class. Institutional Class shares are new and do not have any performance history. The annual returns in the bar chart, the best and worst quarterly returns and the Average Annual Total Returns table below are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year-to-year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance, as represented by the Fund’s Investor Class, over the time periods indicated to that of a broad-based securities market index composed of securities similar to those held by the Fund and an additional index. Past performance, before and after taxes, is not necessarily an indication of how the Institutional Class of the Fund will perform in the future. In addition, the Predecessor Fund was advised by a different investment advisor and subject to different expenses, which may have produced different investment results. The portfolio managers of the Fund, however, were also the portfolio managers of the Predecessor Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com

WASATCH LONG/SHORT FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/09	16.00%
Worst — 12/31/08	-15.94%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Institutional Class Wasatch Long/Short Fund	1 Year	5 Years	Since Inception	Inception Date
Investor Class	8.67%	4.47%	6.00%	Aug. 01, 2003
Investor Class Return after taxes on distributions	8.63%	4.25%	5.23%	Aug. 01, 2003
Investor Class Return after taxes on distributions and sale of Fund shares	5.69%	3.70%	4.76%	Aug. 01, 2003
S&P 500 Index (reflects no deductions for fees, expenses or taxes)	16.00%	1.66%	6.10%	Aug. 01, 2003
Citigroup Three Month U.S. Treasury Bills Index (reflects no deductions for fees, expenses or taxes)	0.07%	0.45%	1.72%	Aug. 01, 2003

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Dividends on short sales are the dividends paid to the lenders of borrowed securities. The expenses related to dividends on short sales are estimated and will vary depending on whether the securities the Fund sells short pay dividends and on the amount of any such dividends. Expenses also include borrowing costs paid to the broker in connection with borrowing the security to be sold short. The rate paid by brokers varies by security.

[2] Other Expenses for Institutional Class shares are estimated based on actual expenses for the Investor Class shares of the Fund during the most recent fiscal year. Wasatch Advisors, Inc., the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.17% (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses) until at least January 31, 2014. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Wasatch Micro Cap Value Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH MICRO CAP VALUE FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 78% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

78.00%

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees

The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund’s most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in micro cap companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets in the equity securities of micro cap companies with market capitalizations of less than $1 billion at the time of purchase.
The Fund may invest up to 30% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly traded in the United States are not defined as foreign companies and are not subject to this limitation.
The Fund may invest in initial public offerings (IPOs).
While the Fund primarily invests in value companies, it may also invest in growth companies if the Advisor believes that current valuation is at a sufficient discount to the projected long term earnings growth rate.
We use a “bottom up” process of fundamental analysis to look for individual companies that we believe are temporarily undervalued but have significant potential for stock price appreciation. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
We typically look for companies that we believe fall into one of these three categories at the time of purchase:

• Undiscovered Gems — Companies with good growth potential which have yet to be broadly discovered by Wall Street analysts, thus leaving them attractively undervalued relative to their expected growth.
• Fallen Angels — High quality growth companies that have experienced a temporary setback and therefore have appealing valuations relative to their long term growth potential.
• Value Momentum — Cheap valuation relative to history, but catalyst for future growth has been identified.
• The Fund may invest a large percentage of its assets in a few sectors, including financials, information technology, consumer discretionary, industrials, health care and materials.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap Company Stock Risk. Micro cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Value Investing Risk. Value investing attempts to identify strong companies whose stocks are selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic value may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide information on how the Investor Class of the Fund has performed over time.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH MICRO CAP VALUE FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/09	40.00%
Worst — 12/31/08	-26.67%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch Micro Cap Value Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.95%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.36%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.01%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

2.32%

^[1]

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.06%)

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

2.26%

1 Year

rr_ExpenseExampleYear01

229

3 Years

rr_ExpenseExampleYear03

719

5 Years

rr_ExpenseExampleYear05

1,235

10 Years

rr_ExpenseExampleYear10

2,651

2004

rr_AnnualReturn2004

21.24%

2005

rr_AnnualReturn2005

9.09%

2006

rr_AnnualReturn2006

28.83%

2007

rr_AnnualReturn2007

7.02%

2008

rr_AnnualReturn2008

(47.20%)

2009

rr_AnnualReturn2009

70.40%

2010

rr_AnnualReturn2010

20.09%

2011

rr_AnnualReturn2011

(10.41%)

2012

rr_AnnualReturn2012

22.10%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

40.00%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(26.67%)

1 Year

rr_AverageAnnualReturnYear01

22.10%

5 Years

rr_AverageAnnualReturnYear05

3.40%

Since Inception

rr_AverageAnnualReturnSinceInception

10.66%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jul. 28, 2003

Return after taxes on distributions | Wasatch Micro Cap Value Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

20.34%

5 Years

rr_AverageAnnualReturnYear05

3.07%

Since Inception

rr_AverageAnnualReturnSinceInception

9.03%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jul. 28, 2003

Return after taxes on distributions and sale of Fund shares | Wasatch Micro Cap Value Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

16.67%

5 Years

rr_AverageAnnualReturnYear05

2.89%

Since Inception

rr_AverageAnnualReturnSinceInception

8.74%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jul. 28, 2003

Russell Microcap® Index (reflects no deductions for fees, expenses or taxes) | Wasatch Micro Cap Value Fund

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

19.75%

5 Years

rr_AverageAnnualReturnYear05

1.46%

Since Inception

rr_AverageAnnualReturnSinceInception

5.73%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jul. 28, 2003

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 2.25% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). Acquired Fund Fees and Expenses are not included in the expense limitation. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date. The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund's most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

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Investor Class | Wasatch Core Growth Fund

WASATCH CORE GROWTH FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s primary investment objective is long-term growth of capital.

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Investor Class Wasatch Core Growth Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Investor Class Wasatch Core Growth Fund Investor Class Shares
Management Fee		1.00%
Distribution/Service (12b-1) Fee		none
Other Expenses		0.23%
Total Annual Fund Operating Expenses	[1]	1.23%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Investor Class Wasatch Core Growth Fund	125	390	675	1,487

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 28% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in smaller growing companies at reasonable prices.
Under normal market conditions, we will invest at least 65% of the Fund’s net assets in the equity securities of growing companies. These companies are usually small to mid-size with market capitalizations of less than $5 billion at the time of purchase.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly 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 individual companies that we believe are stable and have the potential to grow steadily for long periods of time. 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 may invest a large percentage of its assets in a few sectors, including industrials, financials, consumer discretionary, information technology and health care.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small and mid cap stocks may be very sensitive to changing economic conditions and market downturns.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH CORE GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/09	29.50%
Worst — 12/31/08	-27.03%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Investor Class	1 Year	5 Years	10 Years
Wasatch Core Growth Fund	19.19%	4.81%	9.58%
Wasatch Core Growth Fund Return after taxes on distributions	19.19%	4.71%	8.80%
Wasatch Core Growth Fund Return after taxes on distributions and sale of Fund shares	12.48%	4.07%	8.28%
Wasatch Core Growth Fund Russell 2000® Index (reflects no deductions for fees, expenses or taxes)	16.35%	3.56%	9.72%
Wasatch Core Growth Fund Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)	14.59%	3.49%	9.80%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date. There were no reimbursements for the Investor Class shares of the Fund during 2012.

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Institutional Class | Wasatch Emerging Markets Select Fund

WASATCH EMERGING MARKETS SELECT FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Institutional Class Wasatch Emerging Markets Select Fund Institutional Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Institutional Class Wasatch Emerging Markets Select Fund Institutional Class Shares
Management Fee		1.25%
Distribution/Service (12b-1) Fee		none
Other Expenses	[1]	1.04%
Total Annual Fund Operating Expenses	[1]	2.29%
Expense Reimbursement		(0.79%)
Total Annual Fund Operating Expenses After Expense Reimbursement		1.50%

EXAMPLE

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the Fund’s operating expenses (as a percentage of net assets) remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years
Institutional Class Wasatch Emerging Markets Select Fund	153	640

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance.

PRINCIPAL STRATEGIES

The Fund invests primarily in companies of all market capitalizations that are tied economically to emerging market countries.
Under normal market conditions, we will invest at least 80% of the Fund’s assets in the equity securities (including common stock, preferred stock and securities convertible into common stock) of companies that are tied economically to emerging market countries.
Emerging market countries are those currently included in the Morgan Stanley Capital International (MSCI) Emerging Markets Index. We will generally 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 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 with the goal of owning the highest quality growth companies tied economically to emerging market countries. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, supplies and customers.
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 in a few sectors.
The Fund may invest in initial public offerings (IPOs) and early stage companies.
The Fund is non-diversified, meaning that it can concentrate investments in a more limited number of issuers than a diversified fund. Under normal market conditions, the Fund will generally invest in 30 to 50 companies; however, we may invest in fewer or more companies when we believe it is necessary to achieve the Fund’s investment objective.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Convertible Securities Risk. Generally, convertible securities offer lower interest or dividend yields than non-convertible securities of similar quality and less potential for gains or capital appreciation in a rising stock market than other equity securities. They tend to be more volatile than other fixed income securities, and the markets for convertible securities may be less liquid than the markets for common stocks or bonds. The value of convertible securities is susceptible to the risk of market losses attributable to changes in interest rates. An issuer may have the right to buy back certain convertible securities at a time and price that is unfavorable to the Fund.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Non-Diversification Risk. Because the Fund is non-diversified and generally invests in 30 to 50 companies, the Fund will have more exposure to the price movements of a single security or a small group of securities than funds that diversify their investments among many companies. The Fund’s total return and net asset value could fluctuate more than if a greater number of securities were held.

PERFORMANCE

Ordinarily, this section of the prospectus contains information that would allow you to evaluate the performance of the Fund’s Institutional Class using several different measures such as yearly changes in performance, best and worst quarterly returns and average annual total returns before and after taxes compared to a relevant benchmark. However, the Wasatch Emerging Markets Select Fund has only recently commenced operations and does not have a full calendar year of performance.

[1] Other Expenses are based on estimated expenses for the Fund for its first full fiscal year. The Advisor has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses in excess of such limitations). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

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Wasatch Heritage Growth Fund

WASATCH HERITAGE GROWTH FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s primary investment objective is long-term growth of capital.

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Wasatch Heritage Growth Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Wasatch Heritage Growth Fund Investor Class Shares
Management Fee		0.70%
Distribution/Service (12b-1) Fee		none
Other Expenses		0.33%
Total Annual Fund Operating Expenses	[1]	1.03%
Expense Reimbursement		(0.08%)
Total Annual Fund Operating Expenses After Expense Reimbursement		0.95%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Wasatch Heritage Growth Fund Investor Class	97	320	561	1,253

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 26% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in growing mid cap companies at reasonable prices.
Under normal market conditions, the Fund will invest in the equity securities of growing companies with market capitalizations of between $2.5 billion and $15 billion at the time of purchase.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly 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, and we use a process of “bottom up” fundamental analysis to look for individual companies that we believe are stable and have the potential to grow steadily for long periods of time. 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 may invest a large percentage of its assets in a few sectors, including information technology, industrials, consumer discretionary, financials, health care and energy.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH HERITAGE GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/09	17.91%
Worst — 12/31/08	-23.31%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Wasatch Heritage Growth Fund	1 Year	5 Years	Since Inception	Inception Date
Investor Class	9.45%	4.02%	5.37%	Jun. 18, 2004
Investor Class Return after taxes on distributions	8.75%	3.75%	4.89%	Jun. 18, 2004
Investor Class Return after taxes on distributions and sale of Fund shares	7.07%	3.40%	4.56%	Jun. 18, 2004
Russell Midcap® Growth Index (reflects no deductions for fees, expenses or taxes)	15.81%	3.23%	7.14%	Jun. 18, 2004
S&P 500 Index (reflects no deductions for fees, expenses or taxes)	16.00%	1.66%	4.90%	Jun. 18, 2004

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 0.95% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Wasatch Emerging Markets Small Cap Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH EMERGING MARKETS SMALL CAP FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 39% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

39.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

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PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

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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 assets in the equity securities (including common stock, preferred stock and securities convertible into common stock) of companies with market capitalizations of less than US$3 billion at the time of purchase that are tied economically to emerging market countries.
Emerging market countries are those currently included in the Morgan Stanley Capital International (MSCI) Emerging Markets Index. We will generally 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 in a few sectors, including consumer discretionary, financials, industrials, consumer staples, materials, energy, information technology and health care.

Risk [Heading]

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PRINCIPAL RISKS

Risk Narrative [Text Block]

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All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

Risk Lose Money [Text]

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All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

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HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

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The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

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The following tables provide information on how the Investor Class of the Fund has performed over time.

Performance Availability Website Address [Text]

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www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

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The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

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WASATCH EMERGING MARKETS SMALL CAP FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

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Best and Worst Quarterly Returns

Best — 6/30/09	56.10%
Worst — 12/31/08	-32.16%

Performance Table Heading

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Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

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After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

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The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

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The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

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After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch Emerging Markets Small Cap Fund | Investor Class Shares

Risk/Return:

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Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

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none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

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2.00%

Exchange Fee

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none

Maximum Account Fee

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none

Management Fee

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1.75%

Distribution/Service (12b-1) Fee

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none

Other Expenses

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0.38%

Total Annual Fund Operating Expenses

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2.13%

^[1]

Expense Reimbursement

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(0.18%)

Total Annual Fund Operating Expenses After Expense Reimbursement

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1.95%

1 Year

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198

3 Years

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650

5 Years

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1,128

10 Years

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2,447

2008

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(57.08%)

2009

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117.72%

2010

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41.22%

2011

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(14.01%)

2012

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27.75%

Highest Quarterly Return, Label

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Best

Highest Quarterly Return, Date

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Jun. 30, 2009

Highest Quarterly Return

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56.10%

Lowest Quarterly Return, Label

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Worst

Lowest Quarterly Return, Date

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Dec. 31, 2008

Lowest Quarterly Return

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(32.16%)

1 Year

rr_AverageAnnualReturnYear01

27.75%

5 Years

rr_AverageAnnualReturnYear05

7.71%

Since Inception

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6.96%

Inception Date

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Oct. 01, 2007

Wasatch Emerging Markets Small Cap Fund | Return after taxes on distributions | Investor Class Shares

Risk/Return:

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1 Year

rr_AverageAnnualReturnYear01

27.66%

5 Years

rr_AverageAnnualReturnYear05

7.65%

Since Inception

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6.88%

Inception Date

rr_AverageAnnualReturnInceptionDate

Oct. 01, 2007

Wasatch Emerging Markets Small Cap Fund | Return after taxes on distributions and sale of Fund shares | Investor Class Shares

Risk/Return:

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1 Year

rr_AverageAnnualReturnYear01

18.16%

5 Years

rr_AverageAnnualReturnYear05

6.65%

Since Inception

rr_AverageAnnualReturnSinceInception

5.99%

Inception Date

rr_AverageAnnualReturnInceptionDate

Oct. 01, 2007

Wasatch Emerging Markets Small Cap Fund | MSCI Emerging Markets Small Cap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

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1 Year

rr_AverageAnnualReturnYear01

22.22%

^[2]

5 Years

rr_AverageAnnualReturnYear05

0.21%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

(0.05%)

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Oct. 01, 2007

^[2]

Wasatch Emerging Markets Small Cap Fund | MSCI Emerging Markets Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

18.22%

^[2]

5 Years

rr_AverageAnnualReturnYear05

(0.92%)

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

(0.19%)

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Oct. 01, 2007

^[2]

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.95% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

[2] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

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Wasatch Strategic Income Fund

WASATCH STRATEGIC INCOME FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s primary investment objective is to capture current income.

A secondary objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Wasatch Strategic Income Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Wasatch Strategic Income Fund Investor Class Shares
Management Fee		0.70%
Distribution/Service (12b-1) Fee		none
Other Expenses		0.44%
Acquired Fund Fees and Expenses		0.09%
Total Annual Fund Operating Expenses	[1]	1.23%
Expense Reimbursement		(0.19%)
Total Annual Fund Operating Expenses After Expense Reimbursement		1.04%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Wasatch Strategic Income Fund Investor Class	106	373	660	1,477

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 57% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in income-producing securities.
Under normal market conditions, we will invest the Fund’s assets in income-producing domestic and foreign securities, including equity securities (common stock, preferred stocks and securities convertible into common stock) and fixed income securities of companies of all market capitalizations. The Fund is not managed as a balanced portfolio. At times, one type of security may make up a substantial portion of the Fund, while other types may have minimal or no representation.
The Fund may invest its assets in securities issued by foreign companies in developed countries without limit. To a lesser extent, the Fund may invest in foreign companies in emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly traded in the United States are not defined as foreign companies.
In our search for investments, we maintain the flexibility to invest in companies from a variety of industries. The Fund, however, does have a concentration in the financials sector — meaning that at least 25% of the Fund’s total assets will be invested in securities of issuers in the group of industries in the financials sector. For both domestic and foreign securities, we define the group of industries comprising the financials sector to include, among others, Banks (Commercial Banks, Thrifts and Mortgage Finance), Diversified Financial Companies (Diversified Financial Services, Consumer Finance, Capital Markets), Finance Companies, Financial Data Processing Services and Systems, Finance Companies (Small Loan), Financial Information Services, Insurance Companies (Life, Multi-Line, Property-Casualty), Investment Management Companies, Real Estate Companies (Real Estate Investment Trusts [REITs], Real Estate Management and Development Companies), Rental and Leasing Services (Commercial), Savings and Loans, and Securities Brokerage and Services.
The Fund may invest a large percentage of its assets in a few sectors, including financials, information technology and health care.
The Fund may invest in exchange-traded funds (ETFs).
The Fund may make short sales of securities, and may also use derivatives such as put and call options and futures contracts for hedging and non-hedging purposes. The Fund may write put and call options subject to applicable law and SEC guidelines.
In the selection of equity securities, we use “bottom up” fundamental analysis to identify individual companies with attractive, sustainable dividend yields or the potential for dividend growth. In certain situations, the Fund may acquire non-income producing securities if we believe the company has the potential to pay dividends in the future. 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.
Characteristics we consider when investing in equity securities generally include:

• Attractive, sustainable dividend yields or the potential for dividend growth.
• Experienced top management.
• Sustainable competitive advantage.
• Stable demand for products and services.
• Ability to capitalize on favorable long-term trends.

The Fund’s investments in fixed income securities may include domestic and foreign corporate bonds with a variety of maturities (e.g., long-term, intermediate or short-term) and credit qualities (e.g., investment grade or non-investment grade). At certain times the Fund may emphasize one particular maturity or credit quality. The Fund may invest in non-investment grade securities without limitation. The Fund may also invest in U.S. Treasury securities and the debt obligations of foreign governments.
Characteristics we consider when investing in fixed income securities generally include:

• Rates of current income.
• Credit quality of the issuer.
• Maturity, duration and other characteristics of the obligation.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small and mid cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it will have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Derivatives Risk. The Fund may suffer a loss from its use of put and call options and futures contracts, which are forms of derivatives. Derivatives can amplify a gain or loss, potentially earning or losing substantially more money than the actual cost of the derivative instrument, with the potential for unlimited losses on certain instruments. Derivatives may be difficult to value, may become illiquid, and may affect the timing and character of taxes payable by shareholders.
Short Sales Risk. The Fund may make short sales of securities, which means it may experience a loss if the market price of the security increases between the date of the short sale and the date the security is replaced. Short sales may reduce a Fund’s returns or increase volatility.
Investment Companies Risk. The Fund may invest in shares of other investment companies, including foreign and domestic registered and unregistered open-end funds, closed-end funds, and unit investment trusts and exchange-traded funds noted below. Investing in another investment company subjects the Fund to the same risks associated with investing in the securities held by the applicable investment company and the investment strategies employed by such funds (such as the use of leverage). In addition, the benefit of investing in another investment company is largely dependent on the skill of the investment advisor of the underlying company and whether the associated fees and costs involved with investing in such company are offset by the potential gains. As a shareholder in an investment company, a fund will bear its ratable share of that investment company’s expenses including advisory and administrative fees. Shareholders would therefore be subject to duplicative expenses to the extent that the Fund invests in other investment companies.
Exchange-Traded Funds (ETFs) Risk. ETFs are investment companies that are bought and sold on a securities exchange. Shares of ETFs are redeemable only in larger aggregations of a specified number of shares and generally on an in-kind basis. When the Fund invests in an ETF, it will bear additional expenses based on its pro rata share of the ETF’s operating expenses. In addition, the Fund will incur brokerage costs when purchasing and selling shares of ETFs. The risk of owning an ETF generally reflects the risks of the underlying securities held by the ETF and investment strategies employed by such ETF (such as the use of leverage). The market price may also fluctuate due to the supply and demand of the ETF’s shares on the exchange upon which its shares are traded. Lack of liquidity in an ETF could result in the ETF being more volatile than the underlying portfolio of securities. In addition, because of ETF expenses, compared to owning the underlying securities directly, it may be more costly to own an ETF.
REIT Risk. Investments in real estate investment trusts (REITs) subject the Fund to risks associated with the direct ownership of real estate. The value of securities of REITs can be affected by changes in real estate values and rental income, property taxes, interest rates, tax and regulatory requirements and the management skill and creditworthiness of the issuer. In addition, the value of a REIT can depend on the structure and cash flow generated by the REIT and REITs may not have diversified holdings. Because REITs are pooled investment vehicles that have expenses of their own, the Fund will indirectly bear its proportionate share of those expenses.
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. Credit risk is affected by the issuer’s credit status, and is generally higher for non-investment grade securities.
Interest Rate Risk. Interest rate risk is the risk that a debt security’s value will decline due to changes in market interest rates. Even though some interest-bearing securities offer a stable stream of income, their prices will fluctuate with changes in interest rates.
Non-Investment Grade Securities Risk. Non-investment grade securities (also known as “high yield” or “junk bonds”), those rated below investment grade by the primary rating agencies (e.g., below BB/Ba by S&P/Moody’s) tend to have more volatile prices and increased price sensitivity to changing interest rates and adverse economic and business developments than investment grade securities. In addition, compared to investments in investment grade securities, investments in non-investment grade securities are subject to greater risk of loss due to default or decline in credit quality. There is a greater likelihood that adverse economic or company-specific events will make the issuer unable to make interest and/or principal payments, and more susceptible to negative market sentiment, leading to depressed prices and decreased liquidity.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional comparison index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH STRATEGIC INCOME FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/09	21.21%
Worst — 12/31/08	-28.22%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Wasatch Strategic Income Fund	1 Year	5 Years	Since Inception	Inception Date
Investor Class	11.29%	3.08%	4.53%	Feb. 01, 2006
Investor Class Return after taxes on distributions	10.73%	2.05%	2.73%	Feb. 01, 2006
Investor Class Return after taxes on distributions and sale of Fund shares	7.58%	2.04%	2.84%	Feb. 01, 2006
S&P 500 Index (reflects no deductions for fees, expenses or taxes)	16.00%	1.66%	3.78%	Feb. 01, 2006
Barclays Capital U.S. Aggregate Bond Index (reflects no deductions for fees, expenses or taxes)	4.22%	5.95%	5.93%	Feb. 01, 2006

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 0.95% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, and extraordinary expenses). Acquired Fund Fees and Expenses are not included in the expense limitation. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date. The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund's most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

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Investor Class | Wasatch Small Cap Value Fund

WASATCH SMALL CAP VALUE FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Investor Class Wasatch Small Cap Value Fund Investor Class shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Investor Class Wasatch Small Cap Value Fund Investor Class shares
Management Fee	[1]	1.00%
Distribution/Service (12b-1) Fee	[1]	none
Other Expenses	[1]	0.29%
Total Annual Fund Operating Expenses	[1][2]	1.29%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Investor Class Wasatch Small Cap Value Fund	131	408	707	1,556

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 55% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in small companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets in the equity securities of small companies with market capitalizations of less than $2.5 billion at the time of purchase.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly traded in the United States are not defined as foreign companies and are not subject to this limitation.
The Fund may also invest in growth companies if the Advisor believes that current valuation is at a sufficient discount to the projected long-term earnings growth rate.
We use a “bottom-up” process of fundamental analysis to look for individual companies that we believe are temporarily undervalued but have significant potential for stock price appreciation. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
We typically look for companies that we believe fall into one of these three categories at the time of purchase:

• Undiscovered Gems — Companies with good growth potential which have yet to be broadly discovered by Wall Street analysts, thus leaving them attractively undervalued relative to their expected growth.
• Fallen Angels — High quality growth companies that have experienced a temporary setback and therefore have appealing valuations relative to their long term growth potential.
• Quality Value — Quality companies with earnings potential that is not fully reflected in their stock prices.

The Fund may invest a large percentage of its assets in a few sectors, including industrials, information technology, financials, consumer discretionary, health care and energy.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Value Investing Risk. Value investing attempts to identify strong companies whose stocks are selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH SMALL CAP VALUE FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/09	33.91%
Worst — 12/31/08	-34.04%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Investor Class	1 Year	5 Years	10 Years
Wasatch Small Cap Value Fund	16.52%	2.46%	9.49%
Wasatch Small Cap Value Fund Return after taxes on distributions	16.52%	2.46%	8.05%
Wasatch Small Cap Value Fund Return after taxes on distributions and sale of Fund shares	10.74%	2.11%	7.96%
Wasatch Small Cap Value Fund Russell 2000® Value Index (reflects no deductions for fees, expenses or taxes)	18.05%	3.55%	9.50%
Wasatch Small Cap Value Fund Russell 2000® Index (reflects no deductions for fees, expenses or taxes)	16.35%	3.56%	9.72%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Fund's operating expenses have been restated to reflect a reduction in the management fee, effective January 31, 2012, as if such changes had been in effect during the fiscal year ended September 30, 2012. The information has been restated to better reflect anticipated expenses of the Fund.

[2] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date. There were no reimbursements for the Investor Class shares of the Fund during 2012.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Wasatch-Hoisington U.S. Treasury Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH-HOISINGTON U.S. TREASURY FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is to provide a rate of return that exceeds the rate of inflation over a business cycle by investing in U.S. Treasury securities with an emphasis on both income and capital appreciation.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 13% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

13.00%

Expense Example [Heading]

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EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

In pursuit of the Fund’s investment objective, Hoisington Investment Management Company (HIMCO), the Fund’s Sub-Advisor will:

• Typically invest at least 90% of the Fund’s total assets in U.S. Treasury securities and in repurchase agreements collateralized by such securities.
  
• Adjust the average maturity and effective duration of the Fund’s portfolio based on HIMCO’s assessment of multi-year trends in national and international economic conditions and interest rates, changes in inflationary pressures, and the value of long term U.S. Treasury bonds (maturities longer than 20 years) relative to inflation.
  
• Invest in long-term U.S. Treasury bonds, including U.S. Treasury Strips (zero coupon Treasury securities), when HIMCO determines that economic conditions suggest lower inflation and the multi-year trend is toward decreasing interest rates.
  
• Invest in U.S. Treasury bills or notes (maturities less than five years) when HIMCO determines that economic conditions suggest rising inflation and the multi-year trend is toward increasing interest rates.
  

Over the course of a business cycle, under normal market conditions:

• The effective duration of the Fund’s holdings is expected to vary from less than a year to a maximum of 25 years.
  
• The Fund’s holdings will range in maturity from less than a year to a maximum of the longest maturity Treasury bonds available.
  
• When the Fund is invested in longer weighted average maturities it will be more sensitive to changes in market interest rates and its share price may be subject to greater volatility.
  
• The Fund’s portfolio turnover rate will vary substantially from year to year. During some periods, turnover will be well below 50%. At other times, turnover could exceed 200% annually. At these times, increased portfolio turnover may result in higher transaction costs and may also result in taxable capital gains.
  
• Portfolio adjustments may require the sale of securities prior to their maturity date. The goal of these transactions will be to increase income and/or change the duration of the overall portfolio.
  

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

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All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. HIMCO seeks to limit credit risk by investing primarily in U.S. Treasury securities backed by the full faith and credit of the U.S. government which are viewed as carrying minimal credit risk.
Interest Rate Risk. Interest rate risk is the risk that a debt security’s value will decline due to changes in market interest rates. Even though some interest-bearing securities offer a stable stream of income, their prices will fluctuate with changes in interest rates.
Income Risk. Income risk is the potential for a decline in the Fund’s income due to falling interest rates.
Effective Duration. Effective duration is a measure of the responsiveness of a bond’s price to market interest rate changes. For example, if the interest rate increased 1%, a bond with an effective duration of five years would experience a decline in price of 5%. Similarly, if the interest rate increased 1%, the price of a bond with an effective duration of 15 years would decline 15%. At a yield of 5%, the effective duration of the longest maturity U.S. Treasury bond is about 15 years. The effective duration of the longest maturity U.S. zero coupon bond is 30 years. If the interest rate increased 1%, the value of the longest maturity zero coupon bond would decline 30%. Similarly, if the interest rate decreased 1%, the value of the longest maturity zero coupon bond would increase 30%.
Risks of Repurchase Agreements. The main risk of a repurchase agreement is that the original seller might default on its obligation to repurchase the securities. If the seller defaults, the Fund will seek to recover its investment by selling the collateral and could encounter restrictions, costs or delays. The Fund will suffer a loss if it sells the collateral for less than the repurchase price.
Risks of Zero Coupon Treasury Securities. The market prices of zero coupon securities, which do not entitle the holder to periodic interest payments, are generally more volatile than the market prices of securities of comparable quality and similar maturity that do pay interest periodically. Zero coupon securities are more sensitive to fluctuations in interest rates than non-zero coupon securities.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based bond market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide information on how the Investor Class of the Fund has performed over time.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

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WASATCH-HOISINGTON U.S. TREASURY FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 9/30/11	36.15%
Worst — 12/31/10	-11.47%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch-Hoisington U.S. Treasury Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

0.50%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.22%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.72%

^[1]

1 Year

rr_ExpenseExampleYear01

74

3 Years

rr_ExpenseExampleYear03

231

5 Years

rr_ExpenseExampleYear05

401

10 Years

rr_ExpenseExampleYear10

896

2003

rr_AnnualReturn2003

1.29%

2004

rr_AnnualReturn2004

10.22%

2005

rr_AnnualReturn2005

10.49%

2006

rr_AnnualReturn2006

(0.18%)

2007

rr_AnnualReturn2007

10.00%

2008

rr_AnnualReturn2008

37.77%

2009

rr_AnnualReturn2009

(22.56%)

2010

rr_AnnualReturn2010

10.18%

2011

rr_AnnualReturn2011

41.23%

2012

rr_AnnualReturn2012

2.78%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2011

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

36.15%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2010

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(11.47%)

1 Year

rr_AverageAnnualReturnYear01

2.78%

5 Years

rr_AverageAnnualReturnYear05

11.28%

10 Years

rr_AverageAnnualReturnYear10

8.74%

Wasatch-Hoisington U.S. Treasury Fund | Return after taxes on distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

1.69%

5 Years

rr_AverageAnnualReturnYear05

9.50%

10 Years

rr_AverageAnnualReturnYear10

7.10%

Wasatch-Hoisington U.S. Treasury Fund | Return after taxes on distributions and sale of Fund shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.19%

5 Years

rr_AverageAnnualReturnYear05

8.92%

10 Years

rr_AverageAnnualReturnYear10

6.72%

Wasatch-Hoisington U.S. Treasury Fund | Barclays Capital U.S. Aggregate Bond Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.22%

5 Years

rr_AverageAnnualReturnYear05

5.95%

10 Years

rr_AverageAnnualReturnYear10

5.18%

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 0.75% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). There were no reimbursements for the Investor Class shares of the Fund during 2012. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

XML

Wasatch-1st Source Income Fund

WASATCH-1ST SOURCE INCOME FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s investment objective is to seek current income consistent with the preservation of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Wasatch-1st Source Income Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Wasatch-1st Source Income Fund Investor Class Shares
Management Fee		0.55%
Distribution/Service (12b-1) Fee		none
Other Expenses		0.15%
Acquired Fund Fees and Expenses		0.01%
Total Annual Fund Operating Expenses	[1]	0.71%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Wasatch-1st Source Income Fund Investor Class	73	228	396	884

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 48% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund normally invests at least 65% of its total assets in debt securities of all types, including corporate bonds, U.S. government bonds, and variable and floating rate securities.
Consistent with the Wasatch-1st Source Income Fund’s (Income Fund) investment objective, 1st Source Corporation Investment Advisors, Inc. (1st Source), the Fund’s Sub-Advisor, expects the Fund to:

• Invest substantially all, but in no event less than 65%, of the Fund’s total assets at the time of purchase in debt securities.
• Invest in fixed income securities consisting of bonds, fixed income preferred stocks, debentures, notes, zero-coupon securities, mortgage-related and other asset-backed securities, state, municipal or industrial revenue bonds, obligations issued or guaranteed by agencies or instrumentalities of the U.S. government, debt securities convertible into or exchangeable for common stocks, foreign debt securities, income participation loans, guaranteed investment contracts, first mortgage loans and participation certificates in pools of mortgages issued or guaranteed by agencies or instrumentalities of the U.S. government.
• Typically invest in debt securities rated at the time of purchase within the four highest rating categories assigned by one or more nationally recognized statistical rating organizations (NRSROs) or, if unrated, those which 1st Source deems to be of comparable quality. The Fund may also invest up to 10% of its total assets in non-investment grade debt securities.

The Fund may engage in repurchase transactions, credit default swaps, forward contracts, and may also engage in futures transactions solely for hedging purposes and invest in options on futures. The Fund may also invest in other investment companies.
The Fund may purchase securities on a when-issued or delayed delivery basis, in which a security’s price and yield are fixed on a specific date, but payment and delivery are scheduled for a future date beyond the standard settlement period.
It is anticipated that the Fund will have an average maturity of 3 ¹/₂ years to 5 years and a duration of 2 ¹/₂ years to 4 ¹/₂ years.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Interest Rate Risk. Interest rate risk is the risk that a debt security’s value will decline due to changes in market interest rates. Even though some interest-bearing securities offer a stable stream of income, their prices will fluctuate with changes in interest rates.
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. Credit risk is affected by the issuer’s credit status, and is generally higher for non-investment grade securities.
Income Risk. Income risk is the potential for a decline in the Fund’s income due to falling interest rates.
Non-Investment Grade Securities Risk. Non-investment grade securities (also known as “high yield” or “junk bonds”), those rated below investment grade by the primary rating agencies (e.g., below BB/Ba by S&P/Moody’s), tend to have more volatile prices and increased price sensitivity to changing interest rates and adverse economic and business developments than investment grade securities. In addition, compared to investments in investment grade securities, investments in non-investment grade securities are subject to greater risk of loss due to default or decline in credit quality. There is a greater likelihood that adverse economic or company-specific events will make the issuer unable to make interest and/or principal payments, and more susceptible to negative market sentiment, leading to depressed prices and decreased liquidity.
Convertible Securities Risk. The Fund may invest in convertible securities. Convertible securities are preferred stocks or debt obligations that are convertible into common stock. Generally, convertible securities offer lower interest or dividend yields than non-convertible securities of similar quality, and less potential for gains or capital appreciation in a rising stock market than other equity securities. They tend to be more volatile than other fixed income securities, and the markets for convertible securities may be less liquid than the markets for common stocks or bonds. Convertible securities have both equity and fixed income risk characteristics. Like all fixed income securities, the value of convertible securities is susceptible to the risk of market losses attributable to changes in interest rates. The market value of convertible securities tends to decline as interest rates increase. If, however, the market price of the common stock underlying a convertible security approaches or exceeds the conversion price of the convertible security, the convertible security tends to reflect the market price of the underlying common stock. In such a case, a convertible security may lose much or all of its value if the value of the underlying common stock then falls below the conversion price of the security. As the market price of the underlying common stock declines, the convertible security tends to trade increasingly based on its fixed income characteristics, and thus, may not necessarily decline in price as much as the underlying common stock. Additionally, an issuer may have the right to buy back a convertible security at a time and price that is unfavorable to the Fund.
Ratings Agency Risk. Credit quality in the high yield securities market can change suddenly and unexpectedly, and even recently issued credit ratings may not fully reflect the actual risks posed by a particular high yield security. For these reasons, it is generally the policy of 1st Source not to rely exclusively on ratings issued by established NRSROs, but to supplement such ratings with its own independent and ongoing review of credit quality. The achievement of the Fund’s investment objective by investments in such securities may be more dependent on 1st Source’s credit analysis than is the case for higher quality bonds. Should the rating of a portfolio security be downgraded, 1st Source will determine whether it is in the best interests of the Fund to retain or dispose of such security.
Repurchase Agreements Risk. The main risk of a repurchase agreement is that the original seller might default on its obligation to repurchase the securities. If the seller defaults, the Fund will seek to recover its investment by selling the collateral and could encounter restrictions, costs or delays. The Fund will suffer a loss if it sells the collateral for less than the repurchase price.
When-Issued Securities Risk. The Fund may purchase securities on a “when-issued” basis (i.e., for delivery beyond the normal settlement date at a stated price and yield). When the Fund engages in “when-issued” transactions, it relies on the seller to consummate the trade. Failure of the seller to do so may result in the Fund’s incurring a loss or missing the opportunity to obtain a price considered to be advantageous. The Fund will engage in “when-issued” delivery transactions only for the purpose of acquiring portfolio securities consistent with the Fund’s investment objective and strategies and not for investment leverage.
Investment Companies Risk. The Fund may invest in shares of other investment companies, including foreign and domestic registered and unregistered open-end funds, closed-end funds, and unit investment trusts and exchange traded funds. Investing in another investment company subjects the Fund to the same risks associated with investing in the securities held by the applicable investment company and the investment strategies employed by such funds (such as the use of leverage). In addition, the benefit of investing in another investment company is largely dependent on the skill of the investment advisor of the underlying company and whether the associated fees and costs involved with investing in such company are offset by the potential gains. As a shareholder in an investment company, the Fund will bear its ratable share of that investment company’s expenses including advisory and administrative fees. Shareholders would therefore be subject to duplicative expenses to the extent that the Fund invests in other investment companies.
Derivatives Risk. The Fund may suffer a loss from its use of put and call options and futures contracts, which are forms of derivatives. Derivatives can amplify a gain or loss, potentially earning or losing substantially more money than the actual cost of the derivative instrument, with the potential for unlimited losses on certain instruments. Derivatives may be difficult to value, may become illiquid, and may affect the timing and character of taxes payable by shareholders.
Credit Default Swaps Risk. The Fund may enter into credit default swaps, interest rate swaps and currency swaps. Swap agreements will tend to shift a Fund’s investment exposure from one type of investment to another. Depending on how they are used, swap agreements may increase or decrease the overall volatility of the Fund’s portfolio and its share price and yield. Swaps are subject to counterparty risk. The Fund bears the loss of the amount expected to be received under a swap agreement in the event of the default or bankruptcy of a swap agreement counterparty. For this reason, the Fund will enter into swap agreements only with counterparties that meet certain standards of creditworthiness.
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.

HISTORICAL PERFORMANCE

The Fund commenced operations on December 15, 2008 upon the reorganization of the 1st Source Monogram Income Fund, the Fund’s predecessor fund (the “Predecessor Fund”), into the Fund. With the reorganization, the Fund assumed the financial and performance history of the Predecessor Fund. The following tables provide an indication of the historical risk of an investment in the Fund (and Predecessor Fund for periods prior to December 15, 2008). The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance for the years shown in bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to that of a broad-based bond market index. Past performance, before and after taxes, is not necessarily an indication of how the Investor Class of the Fund will perform in the future. In addition, the Predecessor Fund was advised by a different investment advisor and subject to different expenses, which may have produced different investment results. The portfolio manager of the Fund, however, was also the portfolio manager of the Predecessor Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH-1ST SOURCE INCOME FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 9/30/06	2.85%
Worst — 6/30/04	-2.20%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Wasatch-1st Source Income Fund	1 Year	5 Years	10 Years
Investor Class	2.81%	4.08%	3.49%
Investor Class Return after taxes on distributions	2.15%	3.07%	2.25%
Investor Class Return after taxes on distributions and sale of Fund shares	1.84%	2.90%	2.24%
Barclays Capital U.S. Intermediate Government/Credit Bond Index (reflects no deductions for fees, expenses or taxes)	3.89%	5.18%	4.62%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund's most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

XML

Document and Entity Information	12 Months Ended
	Jan. 31, 2013
Risk/Return:
Document Type	485BPOS
Document Period End Date	Sep. 30, 2012
Registrant Name	WASATCH FUNDS TRUST
Central Index Key	0000806633
Amendment Flag	false
Document Creation Date	Jan. 28, 2013
Document Effective Date	Jan. 31, 2013
Prospectus Date	Jan. 31, 2013

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Wasatch-1st Source Income Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH-1ST SOURCE INCOME FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is to seek current income consistent with the preservation of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 48% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

48.00%

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees

The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund’s most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund normally invests at least 65% of its total assets in debt securities of all types, including corporate bonds, U.S. government bonds, and variable and floating rate securities.
Consistent with the Wasatch-1st Source Income Fund’s (Income Fund) investment objective, 1st Source Corporation Investment Advisors, Inc. (1st Source), the Fund’s Sub-Advisor, expects the Fund to:

• Invest substantially all, but in no event less than 65%, of the Fund’s total assets at the time of purchase in debt securities.
• Invest in fixed income securities consisting of bonds, fixed income preferred stocks, debentures, notes, zero-coupon securities, mortgage-related and other asset-backed securities, state, municipal or industrial revenue bonds, obligations issued or guaranteed by agencies or instrumentalities of the U.S. government, debt securities convertible into or exchangeable for common stocks, foreign debt securities, income participation loans, guaranteed investment contracts, first mortgage loans and participation certificates in pools of mortgages issued or guaranteed by agencies or instrumentalities of the U.S. government.
• Typically invest in debt securities rated at the time of purchase within the four highest rating categories assigned by one or more nationally recognized statistical rating organizations (NRSROs) or, if unrated, those which 1st Source deems to be of comparable quality. The Fund may also invest up to 10% of its total assets in non-investment grade debt securities.

The Fund may engage in repurchase transactions, credit default swaps, forward contracts, and may also engage in futures transactions solely for hedging purposes and invest in options on futures. The Fund may also invest in other investment companies.
The Fund may purchase securities on a when-issued or delayed delivery basis, in which a security’s price and yield are fixed on a specific date, but payment and delivery are scheduled for a future date beyond the standard settlement period.
It is anticipated that the Fund will have an average maturity of 3 ¹/₂ years to 5 years and a duration of 2 ¹/₂ years to 4 ¹/₂ years.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Interest Rate Risk. Interest rate risk is the risk that a debt security’s value will decline due to changes in market interest rates. Even though some interest-bearing securities offer a stable stream of income, their prices will fluctuate with changes in interest rates.
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. Credit risk is affected by the issuer’s credit status, and is generally higher for non-investment grade securities.
Income Risk. Income risk is the potential for a decline in the Fund’s income due to falling interest rates.
Non-Investment Grade Securities Risk. Non-investment grade securities (also known as “high yield” or “junk bonds”), those rated below investment grade by the primary rating agencies (e.g., below BB/Ba by S&P/Moody’s), tend to have more volatile prices and increased price sensitivity to changing interest rates and adverse economic and business developments than investment grade securities. In addition, compared to investments in investment grade securities, investments in non-investment grade securities are subject to greater risk of loss due to default or decline in credit quality. There is a greater likelihood that adverse economic or company-specific events will make the issuer unable to make interest and/or principal payments, and more susceptible to negative market sentiment, leading to depressed prices and decreased liquidity.
Convertible Securities Risk. The Fund may invest in convertible securities. Convertible securities are preferred stocks or debt obligations that are convertible into common stock. Generally, convertible securities offer lower interest or dividend yields than non-convertible securities of similar quality, and less potential for gains or capital appreciation in a rising stock market than other equity securities. They tend to be more volatile than other fixed income securities, and the markets for convertible securities may be less liquid than the markets for common stocks or bonds. Convertible securities have both equity and fixed income risk characteristics. Like all fixed income securities, the value of convertible securities is susceptible to the risk of market losses attributable to changes in interest rates. The market value of convertible securities tends to decline as interest rates increase. If, however, the market price of the common stock underlying a convertible security approaches or exceeds the conversion price of the convertible security, the convertible security tends to reflect the market price of the underlying common stock. In such a case, a convertible security may lose much or all of its value if the value of the underlying common stock then falls below the conversion price of the security. As the market price of the underlying common stock declines, the convertible security tends to trade increasingly based on its fixed income characteristics, and thus, may not necessarily decline in price as much as the underlying common stock. Additionally, an issuer may have the right to buy back a convertible security at a time and price that is unfavorable to the Fund.
Ratings Agency Risk. Credit quality in the high yield securities market can change suddenly and unexpectedly, and even recently issued credit ratings may not fully reflect the actual risks posed by a particular high yield security. For these reasons, it is generally the policy of 1st Source not to rely exclusively on ratings issued by established NRSROs, but to supplement such ratings with its own independent and ongoing review of credit quality. The achievement of the Fund’s investment objective by investments in such securities may be more dependent on 1st Source’s credit analysis than is the case for higher quality bonds. Should the rating of a portfolio security be downgraded, 1st Source will determine whether it is in the best interests of the Fund to retain or dispose of such security.
Repurchase Agreements Risk. The main risk of a repurchase agreement is that the original seller might default on its obligation to repurchase the securities. If the seller defaults, the Fund will seek to recover its investment by selling the collateral and could encounter restrictions, costs or delays. The Fund will suffer a loss if it sells the collateral for less than the repurchase price.
When-Issued Securities Risk. The Fund may purchase securities on a “when-issued” basis (i.e., for delivery beyond the normal settlement date at a stated price and yield). When the Fund engages in “when-issued” transactions, it relies on the seller to consummate the trade. Failure of the seller to do so may result in the Fund’s incurring a loss or missing the opportunity to obtain a price considered to be advantageous. The Fund will engage in “when-issued” delivery transactions only for the purpose of acquiring portfolio securities consistent with the Fund’s investment objective and strategies and not for investment leverage.
Investment Companies Risk. The Fund may invest in shares of other investment companies, including foreign and domestic registered and unregistered open-end funds, closed-end funds, and unit investment trusts and exchange traded funds. Investing in another investment company subjects the Fund to the same risks associated with investing in the securities held by the applicable investment company and the investment strategies employed by such funds (such as the use of leverage). In addition, the benefit of investing in another investment company is largely dependent on the skill of the investment advisor of the underlying company and whether the associated fees and costs involved with investing in such company are offset by the potential gains. As a shareholder in an investment company, the Fund will bear its ratable share of that investment company’s expenses including advisory and administrative fees. Shareholders would therefore be subject to duplicative expenses to the extent that the Fund invests in other investment companies.
Derivatives Risk. The Fund may suffer a loss from its use of put and call options and futures contracts, which are forms of derivatives. Derivatives can amplify a gain or loss, potentially earning or losing substantially more money than the actual cost of the derivative instrument, with the potential for unlimited losses on certain instruments. Derivatives may be difficult to value, may become illiquid, and may affect the timing and character of taxes payable by shareholders.
Credit Default Swaps Risk. The Fund may enter into credit default swaps, interest rate swaps and currency swaps. Swap agreements will tend to shift a Fund’s investment exposure from one type of investment to another. Depending on how they are used, swap agreements may increase or decrease the overall volatility of the Fund’s portfolio and its share price and yield. Swaps are subject to counterparty risk. The Fund bears the loss of the amount expected to be received under a swap agreement in the event of the default or bankruptcy of a swap agreement counterparty. For this reason, the Fund will enter into swap agreements only with counterparties that meet certain standards of creditworthiness.
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Fund commenced operations on December 15, 2008 upon the reorganization of the 1st Source Monogram Income Fund, the Fund’s predecessor fund (the “Predecessor Fund”), into the Fund. With the reorganization, the Fund assumed the financial and performance history of the Predecessor Fund. The following tables provide an indication of the historical risk of an investment in the Fund (and Predecessor Fund for periods prior to December 15, 2008). The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance for the years shown in bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to that of a broad-based bond market index. Past performance, before and after taxes, is not necessarily an indication of how the Investor Class of the Fund will perform in the future. In addition, the Predecessor Fund was advised by a different investment advisor and subject to different expenses, which may have produced different investment results. The portfolio manager of the Fund, however, was also the portfolio manager of the Predecessor Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide an indication of the historical risk of an investment in the Fund (and Predecessor Fund for periods prior to December 15, 2008). The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance for the years shown in bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to that of a broad-based bond market index.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Past performance, before and after taxes, is not necessarily an indication of how the Investor Class of the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH-1ST SOURCE INCOME FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 9/30/06	2.85%
Worst — 6/30/04	-2.20%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch-1st Source Income Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

0.55%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.15%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.01%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.71%

^[1]

1 Year

rr_ExpenseExampleYear01

73

3 Years

rr_ExpenseExampleYear03

228

5 Years

rr_ExpenseExampleYear05

396

10 Years

rr_ExpenseExampleYear10

884

2003

rr_AnnualReturn2003

2.43%

2004

rr_AnnualReturn2004

1.81%

2005

rr_AnnualReturn2005

1.01%

2006

rr_AnnualReturn2006

3.72%

2007

rr_AnnualReturn2007

5.61%

2008

rr_AnnualReturn2008

3.54%

2009

rr_AnnualReturn2009

5.98%

2010

rr_AnnualReturn2010

4.22%

2011

rr_AnnualReturn2011

3.86%

2012

rr_AnnualReturn2012

2.81%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2006

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

2.85%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Jun. 30, 2004

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(2.20%)

1 Year

rr_AverageAnnualReturnYear01

2.81%

5 Years

rr_AverageAnnualReturnYear05

4.08%

10 Years

rr_AverageAnnualReturnYear10

3.49%

Wasatch-1st Source Income Fund | Return after taxes on distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.15%

5 Years

rr_AverageAnnualReturnYear05

3.07%

10 Years

rr_AverageAnnualReturnYear10

2.25%

Wasatch-1st Source Income Fund | Return after taxes on distributions and sale of Fund shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

1.84%

5 Years

rr_AverageAnnualReturnYear05

2.90%

10 Years

rr_AverageAnnualReturnYear10

2.24%

Wasatch-1st Source Income Fund | Barclays Capital U.S. Intermediate Government/Credit Bond Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

3.89%

5 Years

rr_AverageAnnualReturnYear05

5.18%

10 Years

rr_AverageAnnualReturnYear10

4.62%

[1] The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund's most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Wasatch Small Cap Growth Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH SMALL CAP GROWTH FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s primary investment objective is long-term growth of capital.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 20% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

20.00%

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees

The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund’s most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in small growth companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets in the equity securities of small companies with market capitalizations of less than $2.5 billion at the time of purchase.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly traded in the United States are not defined as foreign companies and are not subject to this limitation.
Within the Fund’s portfolio, we seek to create a blend of “core” companies that we believe have the potential to grow steadily over long periods of time at faster rates than average large companies, and “high growth” companies that we believe have the potential to grow faster and more aggressively than core companies.
We use a “bottom up” process of fundamental analysis to look for individual companies that we believe have superior growth prospects. 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 may invest a large percentage of its assets in a few sectors, including information technology, industrials, consumer discretionary, health care, energy and financials.
The Fund may invest in initial public offerings (IPOs).

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide information on how the Investor Class of the Fund has performed over time.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

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WASATCH SMALL CAP GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/03	25.79%
Worst — 12/31/08	-22.04%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch Small Cap Growth Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

(2.00%)

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.00%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.24%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.02%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.26%

^[1]

1 Year

rr_ExpenseExampleYear01

128

3 Years

rr_ExpenseExampleYear03

399

5 Years

rr_ExpenseExampleYear05

691

10 Years

rr_ExpenseExampleYear10

1,522

2003

rr_AnnualReturn2003

37.43%

2004

rr_AnnualReturn2004

13.36%

2005

rr_AnnualReturn2005

5.14%

2006

rr_AnnualReturn2006

8.40%

2007

rr_AnnualReturn2007

8.36%

2008

rr_AnnualReturn2008

(41.66%)

2009

rr_AnnualReturn2009

48.74%

2010

rr_AnnualReturn2010

28.92%

2011

rr_AnnualReturn2011

(0.06%)

2012

rr_AnnualReturn2012

16.95%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2003

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

25.79%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(22.04%)

1 Year

rr_AverageAnnualReturnYear01

16.95%

5 Years

rr_AverageAnnualReturnYear05

5.51%

10 Years

rr_AverageAnnualReturnYear10

9.66%

Wasatch Small Cap Growth Fund | Return after taxes on distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

15.79%

5 Years

rr_AverageAnnualReturnYear05

5.16%

10 Years

rr_AverageAnnualReturnYear10

8.93%

Wasatch Small Cap Growth Fund | Return after taxes on distributions and sale of Fund shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

12.54%

5 Years

rr_AverageAnnualReturnYear05

4.73%

10 Years

rr_AverageAnnualReturnYear10

8.46%

Wasatch Small Cap Growth Fund | Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

14.59%

5 Years

rr_AverageAnnualReturnYear05

3.49%

10 Years

rr_AverageAnnualReturnYear10

9.80%

Wasatch Small Cap Growth Fund | Russell 2000® Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

16.35%

5 Years

rr_AverageAnnualReturnYear05

3.56%

10 Years

rr_AverageAnnualReturnYear10

9.72%

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). Acquired Fund Fees and Expenses are not included in the expense limitation. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date. There were no reimbursements for the Investor Class shares of the Fund during 2012. The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund's most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	WASATCH FUNDS TRUST
Prospectus Date	rr_ProspectusDate	Jan. 31, 2013
Institutional Class | Wasatch Emerging Markets Select Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	WASATCH EMERGING MARKETS SELECT FUND — Summary
Objective [Heading]	rr_ObjectiveHeading	INVESTMENT OBJECTIVE
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund’s investment objective is long-term growth of capital.
Expense [Heading]	rr_ExpenseHeading	FEES AND EXPENSES OF THE FUND
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The tables below describe the fees and expenses that you may pay if you buy, sell or hold shares of the Fund.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	SHAREHOLDER FEES (fees paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	January 31, 2014
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	PORTFOLIO TURNOVER
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance.
Other Expenses, New Fund, Based on Estimates [Text]	rr_OtherExpensesNewFundBasedOnEstimates	Other Expenses are based on estimated expenses for the Fund for its first full fiscal year.
Expense Example [Heading]	rr_ExpenseExampleHeading	EXAMPLE
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the Fund’s operating expenses (as a percentage of net assets) remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	PRINCIPAL STRATEGIES
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund invests primarily in companies of all market capitalizations that are tied economically to emerging market countries. Under normal market conditions, we will invest at least 80% of the Fund’s assets in the equity securities (including common stock, preferred stock and securities convertible into common stock) of companies that are tied economically to emerging market countries. Emerging market countries are those currently included in the Morgan Stanley Capital International (MSCI) Emerging Markets Index. We will generally 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 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 with the goal of owning the highest quality growth companies tied economically to emerging market countries. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, supplies and customers. 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 in a few sectors. The Fund may invest in initial public offerings (IPOs) and early stage companies. The Fund is non-diversified, meaning that it can concentrate investments in a more limited number of issuers than a diversified fund. Under normal market conditions, the Fund will generally invest in 30 to 50 companies; however, we may invest in fewer or more companies when we believe it is necessary to achieve the Fund’s investment objective.
Risk [Heading]	rr_RiskHeading	PRINCIPAL RISKS
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. The Fund is subject to the following principal investment risks: Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market. Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline. Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates. Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies. Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price. Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets. Convertible Securities Risk. Generally, convertible securities offer lower interest or dividend yields than non-convertible securities of similar quality and less potential for gains or capital appreciation in a rising stock market than other equity securities. They tend to be more volatile than other fixed income securities, and the markets for convertible securities may be less liquid than the markets for common stocks or bonds. The value of convertible securities is susceptible to the risk of market losses attributable to changes in interest rates. An issuer may have the right to buy back certain convertible securities at a time and price that is unfavorable to the Fund. Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors. Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information. Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies. Non-Diversification Risk. Because the Fund is non-diversified and generally invests in 30 to 50 companies, the Fund will have more exposure to the price movements of a single security or a small group of securities than funds that diversify their investments among many companies. The Fund’s total return and net asset value could fluctuate more than if a greater number of securities were held.
Risk Lose Money [Text]	rr_RiskLoseMoney	All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	Non-Diversification Risk. Because the Fund is non-diversified and generally invests in 30 to 50 companies, the Fund will have more exposure to the price movements of a single security or a small group of securities than funds that diversify their investments among many companies. The Fund’s total return and net asset value could fluctuate more than if a greater number of securities were held.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	PERFORMANCE
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	Ordinarily, this section of the prospectus contains information that would allow you to evaluate the performance of the Fund’s Institutional Class using several different measures such as yearly changes in performance, best and worst quarterly returns and average annual total returns before and after taxes compared to a relevant benchmark. However, the Wasatch Emerging Markets Select Fund has only recently commenced operations and does not have a full calendar year of performance.
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	Ordinarily, this section of the prospectus contains information that would allow you to evaluate the performance of the Fund’s Institutional Class using several different measures such as yearly changes in performance, best and worst quarterly returns and average annual total returns before and after taxes compared to a relevant benchmark. However, the Wasatch Emerging Markets Select Fund has only recently commenced operations and does not have a full calendar year of performance.
Institutional Class | Wasatch Emerging Markets Select Fund | Institutional Class Shares
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	rr_RedemptionFeeOverRedemption	2.00%
Exchange Fee	rr_ExchangeFeeOverRedemption	none
Maximum Account Fee	rr_MaximumAccountFeeOverAssets	none
Management Fee	rr_ManagementFeesOverAssets	1.25%
Distribution/Service (12b-1) Fee	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	1.04%	[1]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	2.29%	[1]
Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.79%)
Total Annual Fund Operating Expenses After Expense Reimbursement	rr_NetExpensesOverAssets	1.50%
1 Year	rr_ExpenseExampleYear01	153
3 Years	rr_ExpenseExampleYear03	640

[1] Other Expenses are based on estimated expenses for the Fund for its first full fiscal year. The Advisor has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses in excess of such limitations). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

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Wasatch Frontier Emerging Small Countries Fund

WASATCH FRONTIER EMERGING SMALL COUNTRIES FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Wasatch Frontier Emerging Small Countries Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 90 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Wasatch Frontier Emerging Small Countries Fund Investor Class Shares
Management Fee		1.75%
Distribution/Service (12b-1) Fee		none
Other Expenses	[1]	1.89%
Total Annual Fund Operating Expenses	[1]	3.64%
Expense Reimbursement		(1.39%)
Total Annual Fund Operating Expenses After Expense Reimbursement		2.25%

EXAMPLE

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Wasatch Frontier Emerging Small Countries Fund Investor Class	228	987	1,766	3,809

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance.

PRINCIPAL STRATEGIES

The Fund invests primarily in the equity securities of companies of all market capitalizations that are tied economically to frontier markets and small emerging market countries.
Under normal market conditions, we will invest at least 80% of the Fund’s assets in the equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights and other securities with equity characteristics) of companies that are tied economically to frontier markets and small emerging market countries.
“Frontier markets” include any country that is outside the Morgan Stanley Capital International (MSCI) All Country World Index, and also any country that is currently included in the Russell Frontier Index, the S&P Frontier Broad Market Index (BMI), the MSCI Frontier Markets Index, or similar market indices, or that, in our opinion, have similar characteristics regardless of their inclusion in an index.
“Emerging markets” include those countries currently considered to be developing as per their inclusion in the MSCI Emerging Markets Index. We consider a “small emerging market country” to be any country that individually constitutes not more than 7% of the MSCI Emerging Markets Index or the S&P Emerging BMI.
We will generally consider qualifying investments to be in companies that are listed on an exchange in a frontier market or small emerging market country, that are legally domiciled in a frontier market or small emerging market country, that have at least 50% of their assets in a frontier market or small emerging market country, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services provided in a frontier market or small emerging market country. The Fund will not be required to sell a security because the market to which it is economically tied is no longer what we consider to be a frontier market or a small emerging market country.
In general, frontier markets and small emerging market countries, with the exception of the oil-producing Persian Gulf States, tend to have relatively low gross national product per capita compared to the larger traditionally-recognized emerging markets and the world’s major developed economies. Frontier and small emerging market countries include the least developed markets even by emerging market standards. We believe frontier markets and small emerging market countries offer investment opportunities that arise from long-term trends in demographics, deregulation, offshore outsourcing and improving corporate governance.
The Fund may invest in the equity securities of companies of any size, although we expect a significant portion of the Fund’s assets to be invested in the equity securities of companies under US$3 billion at the time of purchase.
We travel extensively outside 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 with the goal of owning the highest quality growth companies tied economically to frontier markets and small emerging market countries.
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 in a few sectors, including financials.
We may also invest in initial public offerings (IPOs).
The Fund is non-diversified, meaning that it can concentrate investments in a more limited number of issuers than a diversified fund.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Frontier Markets Risk. In addition to the risks of investing in foreign securities and emerging markets, frontier market securities involve unique risks, such as exposure to economies less diverse and mature than those of the U.S. or more established foreign markets. Economic or political instability may cause larger price changes in frontier market securities than in securities of issuers based in more developed foreign countries, including securities of issuers in larger emerging markets. Frontier markets generally receive less investor attention than developed markets and larger emerging markets. These risks can result in the potential for extreme price volatility and illiquidity.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Liquidity Risk. From time to time, the trading market for a particular security or type of security in which the Fund invests may become less liquid or even illiquid. Reduced liquidity will have an adverse impact on the Fund’s ability to sell such securities when necessary to meet the Fund’s liquidity needs or in response to a specific economic event. Market quotations for such securities may be volatile.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Non-Diversification Risk. The Fund can invest a larger portion of its assets in the stocks of a limited number of companies than a diversified fund, which means it may have more exposure to the price movements of a single security or small group of securities than funds that diversify their investments among many companies.

PERFORMANCE

Ordinarily, this section of the prospectus contains information that would allow you to evaluate the performance of the Fund’s Investor Class using several different measures such as yearly changes in performance, best and worst quarterly returns and average annual total returns before and after taxes compared to a relevant benchmark. However, the Wasatch Frontier Emerging Small Countries Fund commenced operations on January 31, 2012 and does not have a full calendar year of performance.

[1] Other Expenses are based on estimated expenses for the Fund's first full fiscal year. The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 2.25% (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses) until at least January 31, 2014. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

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Wasatch Small Cap Growth Fund

WASATCH SMALL CAP GROWTH FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s primary investment objective is long-term growth of capital.

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Wasatch Small Cap Growth Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Wasatch Small Cap Growth Fund Investor Class Shares
Management Fee		1.00%
Distribution/Service (12b-1) Fee		none
Other Expenses		0.24%
Acquired Fund Fees and Expenses		0.02%
Total Annual Fund Operating Expenses	[1]	1.26%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Wasatch Small Cap Growth Fund Investor Class	128	399	691	1,522

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 20% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in small growth companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets in the equity securities of small companies with market capitalizations of less than $2.5 billion at the time of purchase.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly traded in the United States are not defined as foreign companies and are not subject to this limitation.
Within the Fund’s portfolio, we seek to create a blend of “core” companies that we believe have the potential to grow steadily over long periods of time at faster rates than average large companies, and “high growth” companies that we believe have the potential to grow faster and more aggressively than core companies.
We use a “bottom up” process of fundamental analysis to look for individual companies that we believe have superior growth prospects. 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 may invest a large percentage of its assets in a few sectors, including information technology, industrials, consumer discretionary, health care, energy and financials.
The Fund may invest in initial public offerings (IPOs).

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH SMALL CAP GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/03	25.79%
Worst — 12/31/08	-22.04%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Wasatch Small Cap Growth Fund	1 Year	5 Years	10 Years
Investor Class	16.95%	5.51%	9.66%
Investor Class Return after taxes on distributions	15.79%	5.16%	8.93%
Investor Class Return after taxes on distributions and sale of Fund shares	12.54%	4.73%	8.46%
Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)	14.59%	3.49%	9.80%
Russell 2000® Index (reflects no deductions for fees, expenses or taxes)	16.35%	3.56%	9.72%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). Acquired Fund Fees and Expenses are not included in the expense limitation. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date. There were no reimbursements for the Investor Class shares of the Fund during 2012. The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund's most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Investor Class | Wasatch Emerging India Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH EMERGING INDIA FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term appreciation of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 17% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

17.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in companies tied economically to India.
Under normal market conditions, we will invest at least 80% of the Fund’s assets in the equity securities (including common stock, preferred stock and securities convertible into common stock) of companies tied economically to India.
We will generally consider qualifying investments to be in companies that are listed on an Indian exchange, that have at least 50% of their assets in India, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services performed in India.
The Fund is expected to invest across market capitalization levels, ranging from small capitalization stocks to larger capitalization stocks. However, we expect the Fund to invest a significant portion of its assets in small to mid-size companies with market capitalizations of less than $5 billion at the time of purchase.
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.
The Fund may invest a large percentage of its assets in a few sectors, including financials, consumer discretionary, industrials, consumer staples, materials and information technology.
We may also invest in initial public offerings (IPOs).
The Fund is non-diversified, meaning that it can concentrate investments in a more limited number of issuers than a diversified fund.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Indian Market Risk. Government actions, bureaucratic obstacles and inconsistent economic and tax reform within the Indian government have had a significant effect on the economy and could adversely affect market conditions, deter economic growth and reduce the profitability of private enterprises. Global factors and foreign actions may inhibit the flow of foreign capital on which India is dependent to sustain its growth. Large portions of many Indian companies remain in the hands of their founders (including members of their families). Family-controlled companies may have weaker and less transparent corporate governance, which increases the potential for loss and unequal treatment of investors. India experiences many of the market risks associated with developing economies, including relatively low levels of liquidity, which may result in extreme volatility in the prices of Indian securities. Religious, cultural and military disputes persist in India, and between India and Pakistan (as well as sectarian groups within each country). The threat of aggression in the region could hinder development of the Indian economy, and escalating tensions could impact the broader region, including China.
Because the Fund will concentrate its investments in a single region of the world, the value of the Fund’s shares may be affected by events that adversely affect India and may fluctuate more than the value of a less concentrated fund’s shares.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries (such as India) include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Non-Diversification Risk. The Fund can invest a larger portion of its assets in the stocks of a limited number of companies than a diversified fund, which means it may have more exposure to the price movements of a single security or small group of securities than funds that diversify their investments among many companies.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Nondiversified Status [Text]

rr_RiskNondiversifiedStatus

Non-Diversification Risk. The Fund can invest a larger portion of its assets in the stocks of a limited number of companies than a diversified fund, which means it may have more exposure to the price movements of a single security or small group of securities than funds that diversify their investments among many companies.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over the last calendar year and since inception. Past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing the Fund’s performance, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the calendar year shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide information on how the Investor Class of the Fund has performed over the last calendar year and since inception.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH EMERGING INDIA FUND — INVESTOR CLASS
Calendar Year Total Return

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 3/31/12	21.43%
Worst — 6/30/12	-6.95%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Investor Class | Wasatch Emerging India Fund | Investor Class shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.50%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

1.91%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

3.41%

^[1]

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(1.46%)

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.95%

1 Year

rr_ExpenseExampleYear01

198

3 Years

rr_ExpenseExampleYear03

912

5 Years

rr_ExpenseExampleYear05

1,649

10 Years

rr_ExpenseExampleYear10

3,596

2012

rr_AnnualReturn2012

33.77%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Mar. 31, 2012

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

21.43%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Jun. 30, 2012

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(6.95%)

1 Year

rr_AverageAnnualReturnYear01

33.77%

Since Inception

rr_AverageAnnualReturnSinceInception

2.34%

Inception Date

rr_AverageAnnualReturnInceptionDate

Apr. 26, 2011

Investor Class | Wasatch Emerging India Fund | Return after taxes on distributions | Investor Class shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

33.77%

Since Inception

rr_AverageAnnualReturnSinceInception

2.25%

Inception Date

rr_AverageAnnualReturnInceptionDate

Apr. 26, 2011

Investor Class | Wasatch Emerging India Fund | Return after taxes on distributions and sale of Fund shares | Investor Class shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

21.95%

Since Inception

rr_AverageAnnualReturnSinceInception

1.97%

Inception Date

rr_AverageAnnualReturnInceptionDate

Apr. 26, 2011

Investor Class | Wasatch Emerging India Fund | MSCI India Investable Market Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

27.28%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

(11.14%)

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Apr. 26, 2011

^[2]

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.95% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

[2] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	WASATCH FUNDS TRUST
Prospectus Date	rr_ProspectusDate	Jan. 31, 2013
Investor Class | Wasatch Emerging Markets Select Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	WASATCH EMERGING MARKETS SELECT FUND — Summary
Objective [Heading]	rr_ObjectiveHeading	INVESTMENT OBJECTIVE
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund’s investment objective is long-term growth of capital.
Expense [Heading]	rr_ExpenseHeading	FEES AND EXPENSES OF THE FUND
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The tables below describe the fees and expenses that you may pay if you buy, sell or hold shares of the Fund.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	SHAREHOLDER FEES (fees paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	January 31, 2014
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	PORTFOLIO TURNOVER
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance.
Other Expenses, New Fund, Based on Estimates [Text]	rr_OtherExpensesNewFundBasedOnEstimates	Other Expenses are based on estimated expenses for the Investor Class of the Fund for its first full fiscal year.
Expense Example [Heading]	rr_ExpenseExampleHeading	EXAMPLE
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the Fund’s operating expenses (as a percentage of net assets) remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	PRINCIPAL STRATEGIES
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund invests primarily in companies of all market capitalizations that are tied economically to emerging market countries. Under normal market conditions, we will invest at least 80% of the Fund’s assets in the equity securities (including common stock, preferred stock and securities convertible into common stock) of companies that are tied economically to emerging market countries. Emerging market countries are those currently included in the Morgan Stanley Capital International (MSCI) Emerging Markets Index. We will generally 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 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 with the goal of owning the highest quality growth companies tied economically to emerging market countries. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers. 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 in a few sectors. The Fund may invest in initial public offerings (IPOs) and early stage companies. The Fund is non-diversified, meaning that it can concentrate investments in a more limited number of issuers than a diversified fund. Under normal market conditions, the Fund will generally invest in 30 to 50 companies; however, we may invest in fewer or more companies when we believe it is necessary to achieve the Fund’s investment objective.
Risk [Heading]	rr_RiskHeading	PRINCIPAL RISKS
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. The Fund is subject to the following principal investment risks: Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market. Stock Selection Risk. The Fund invests in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline. Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates. Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies. Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price. Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets. Convertible Securities Risk. Generally, convertible securities offer lower interest or dividend yields than non-convertible securities of similar quality and less potential for gains or capital appreciation in a rising stock market than other equity securities. They tend to be more volatile than other fixed income securities, and the markets for convertible securities may be less liquid than the markets for common stocks or bonds. The value of convertible securities is susceptible to the risk of market losses attributable to changes in interest rates. An issuer may have the right to buy back certain convertible securities at a time and price that is unfavorable to the Fund. Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors. Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information. Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies. Non-Diversification Risk. Because the Fund is non-diversified and generally invests in 30 to 50 companies, the Fund will have more exposure to the price movements of a single security or a small group of securities than funds that diversify their investments among many companies. The Fund’s total return and net asset value could fluctuate more than if a greater number of securities were held.
Risk Lose Money [Text]	rr_RiskLoseMoney	All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	Non-Diversification Risk. Because the Fund is non-diversified and generally invests in 30 to 50 companies, the Fund will have more exposure to the price movements of a single security or a small group of securities than funds that diversify their investments among many companies. The Fund’s total return and net asset value could fluctuate more than if a greater number of securities were held.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	PERFORMANCE
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	Ordinarily, this section of the prospectus contains information that would allow you to evaluate the performance of the Fund’s Investor Class using several different measures such as yearly changes in performance, best and worst quarterly returns and average annual total returns before and after taxes compared to a relevant benchmark. However, the Wasatch Emerging Markets Select Fund has only recently commenced operations and does not have a full calendar year of performance.
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	Ordinarily, this section of the prospectus contains information that would allow you to evaluate the performance of the Fund’s Investor Class using several different measures such as yearly changes in performance, best and worst quarterly returns and average annual total returns before and after taxes compared to a relevant benchmark. However, the Wasatch Emerging Markets Select Fund has only recently commenced operations and does not have a full calendar year of performance.
Investor Class | Wasatch Emerging Markets Select Fund | Investor Class Shares
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	rr_RedemptionFeeOverRedemption	2.00%
Exchange Fee	rr_ExchangeFeeOverRedemption	none
Maximum Account Fee	rr_MaximumAccountFeeOverAssets	none
Management Fee	rr_ManagementFeesOverAssets	1.25%
Distribution/Service (12b-1) Fee	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	1.02%	[1]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	2.27%	[1]
Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.58%)
Total Annual Fund Operating Expenses After Expense Reimbursement	rr_NetExpensesOverAssets	1.69%
1 Year	rr_ExpenseExampleYear01	172
3 Years	rr_ExpenseExampleYear03	654

[1] Other Expenses are based on estimated expenses for the Investor Class of the Fund for its first full fiscal year. The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.69% (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses in excess of such limitations) until at least January 31, 2014. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

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Investor Class | Wasatch Emerging India Fund

WASATCH EMERGING INDIA FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term appreciation of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Investor Class Wasatch Emerging India Fund Investor Class shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Investor Class Wasatch Emerging India Fund Investor Class shares
Management Fee		1.50%
Distribution/Service (12b-1) Fee		none
Other Expenses		1.91%
Total Annual Fund Operating Expenses	[1]	3.41%
Expense Reimbursement		(1.46%)
Total Annual Fund Operating Expenses After Expense Reimbursement		1.95%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Investor Class Wasatch Emerging India Fund	198	912	1,649	3,596

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 17% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in companies tied economically to India.
Under normal market conditions, we will invest at least 80% of the Fund’s assets in the equity securities (including common stock, preferred stock and securities convertible into common stock) of companies tied economically to India.
We will generally consider qualifying investments to be in companies that are listed on an Indian exchange, that have at least 50% of their assets in India, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services performed in India.
The Fund is expected to invest across market capitalization levels, ranging from small capitalization stocks to larger capitalization stocks. However, we expect the Fund to invest a significant portion of its assets in small to mid-size companies with market capitalizations of less than $5 billion at the time of purchase.
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.
The Fund may invest a large percentage of its assets in a few sectors, including financials, consumer discretionary, industrials, consumer staples, materials and information technology.
We may also invest in initial public offerings (IPOs).
The Fund is non-diversified, meaning that it can concentrate investments in a more limited number of issuers than a diversified fund.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Indian Market Risk. Government actions, bureaucratic obstacles and inconsistent economic and tax reform within the Indian government have had a significant effect on the economy and could adversely affect market conditions, deter economic growth and reduce the profitability of private enterprises. Global factors and foreign actions may inhibit the flow of foreign capital on which India is dependent to sustain its growth. Large portions of many Indian companies remain in the hands of their founders (including members of their families). Family-controlled companies may have weaker and less transparent corporate governance, which increases the potential for loss and unequal treatment of investors. India experiences many of the market risks associated with developing economies, including relatively low levels of liquidity, which may result in extreme volatility in the prices of Indian securities. Religious, cultural and military disputes persist in India, and between India and Pakistan (as well as sectarian groups within each country). The threat of aggression in the region could hinder development of the Indian economy, and escalating tensions could impact the broader region, including China.
Because the Fund will concentrate its investments in a single region of the world, the value of the Fund’s shares may be affected by events that adversely affect India and may fluctuate more than the value of a less concentrated fund’s shares.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries (such as India) include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Non-Diversification Risk. The Fund can invest a larger portion of its assets in the stocks of a limited number of companies than a diversified fund, which means it may have more exposure to the price movements of a single security or small group of securities than funds that diversify their investments among many companies.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over the last calendar year and since inception. Past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing the Fund’s performance, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the calendar year shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH EMERGING INDIA FUND — INVESTOR CLASS
Calendar Year Total Return

Best and Worst Quarterly Returns

Best — 3/31/12	21.43%
Worst — 6/30/12	-6.95%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Investor Class		1 Year	Since Inception	Inception Date
Wasatch Emerging India Fund		33.77%	2.34%	Apr. 26, 2011
Wasatch Emerging India Fund Return after taxes on distributions		33.77%	2.25%	Apr. 26, 2011
Wasatch Emerging India Fund Return after taxes on distributions and sale of Fund shares		21.95%	1.97%	Apr. 26, 2011
Wasatch Emerging India Fund MSCI India Investable Market Index (reflects no deductions for fees, expenses or taxes)	[1]	27.28%	(11.14%)	Apr. 26, 2011

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.95% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

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Wasatch Emerging Markets Small Cap Fund

WASATCH EMERGING MARKETS SMALL CAP FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Wasatch Emerging Markets Small Cap Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Wasatch Emerging Markets Small Cap Fund Investor Class Shares
Management Fee		1.75%
Distribution/Service (12b-1) Fee		none
Other Expenses		0.38%
Total Annual Fund Operating Expenses	[1]	2.13%
Expense Reimbursement		(0.18%)
Total Annual Fund Operating Expenses After Expense Reimbursement		1.95%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Wasatch Emerging Markets Small Cap Fund Investor Class	198	650	1,128	2,447

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 39% of the average value of its portfolio.

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 assets in the equity securities (including common stock, preferred stock and securities convertible into common stock) of companies with market capitalizations of less than US$3 billion at the time of purchase that are tied economically to emerging market countries.
Emerging market countries are those currently included in the Morgan Stanley Capital International (MSCI) Emerging Markets Index. We will generally 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 in a few sectors, including consumer discretionary, financials, industrials, consumer staples, materials, energy, information technology and health care.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH EMERGING MARKETS SMALL CAP FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/09	56.10%
Worst — 12/31/08	-32.16%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Wasatch Emerging Markets Small Cap Fund		1 Year	5 Years	Since Inception	Inception Date
Investor Class		27.75%	7.71%	6.96%	Oct. 01, 2007
Investor Class Return after taxes on distributions		27.66%	7.65%	6.88%	Oct. 01, 2007
Investor Class Return after taxes on distributions and sale of Fund shares		18.16%	6.65%	5.99%	Oct. 01, 2007
MSCI Emerging Markets Small Cap Index (reflects no deductions for fees, expenses or taxes)	[1]	22.22%	0.21%	(0.05%)	Oct. 01, 2007
MSCI Emerging Markets Index (reflects no deductions for fees, expenses or taxes)	[1]	18.22%	(0.92%)	(0.19%)	Oct. 01, 2007

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.95% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

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Investor Class | Wasatch Long/Short Fund

WASATCH LONG/SHORT FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s investment objective is capital appreciation.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Investor Class Wasatch Long/Short Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses Wasatch Long/Short Fund		Investor Class Shares	Investor Class Investor Class Shares
Management Fee			1.10%
Distribution/Service (12b-1) Fee			none
Other Expenses			0.17%
Dividend Expense on Short Sales/Interest Expense	[1]	0.24%
Total Annual Fund Operating Expenses			1.51%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Investor Class Wasatch Long/Short Fund	154	478	824	1,801

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 71% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in equity securities by maintaining long equity positions and short equity positions.
We seek to achieve higher risk-adjusted returns with lower volatility compared to the equity markets in general (as represented by the S&P 500 Index). Under normal market conditions, we will invest the Fund’s assets in the equity securities of companies with market capitalizations of at least $100 million at the time of purchase that we have identified as being undervalued (long equity positions) and we will sell short those securities (short equity positions) that we have identified as being overvalued. The equity securities in which the Fund invests include common stocks, preferred stocks, securities convertible into or exchangeable for common stocks, warrants and any rights to purchase common stocks and other securities with equity characteristics.
The Fund may at any time have either a net long exposure or a net short exposure to the equity markets and the Fund will not be managed to maintain either net long or net short market exposure.
The Fund may invest in early stage companies and initial public offerings (IPOs).
We believe that the best opportunities to make both short and long equity investments are when the market’s perception of the values of individual companies (measured by the stock price) differs widely from our assessment of the intrinsic values of such companies. We further believe that opportunities to invest in undervalued and overvalued stocks arise due to a variety of market inefficiencies including:

• Changes in market participant psychology and circumstances.
• Imperfect information.
• Forecasts and projections by Wall Street analysts and company representatives that differ from experienced reality.

When evaluating a potential long or short investment for the Fund, we employ a comprehensive valuation analysis intended to establish a range for fair valuation or intrinsic company value, with particular emphasis on company fundamentals.
Along with long positions, the Long/Short Fund intends to engage in short sales of securities of companies that we believe:

• Have earnings that appear to be reflected in the current price.
• Are likely to fall short of market expectations.
• Are in industries exhibiting weaknesses.
• Have poor management.
• Are likely to suffer an event affecting long-term earnings.

The Fund may invest in fixed income securities of any maturity consisting of corporate notes, bonds and debentures, including those that are rated less than investment grade at the time of purchase.
The Fund is non-diversified meaning that it can concentrate investments in a more limited number of issuers than a diversified fund.
The Fund may invest a large percentage of its assets in a few sectors, including information technology, financials, energy, consumer discretionary, materials, industrials and consumer staples.
The Fund is expected to have a high portfolio turnover rate.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Market Direction Risk. Since the Fund has both a “long” and a “short” portfolio, an investment in the Fund will involve market risks associated with different types of investment decisions than those made for a typical “long only” stock fund. The Fund’s results will suffer both when there is a general stock market advance and the Fund holds significant “short” equity positions, or when there is a general stock market decline and the Fund holds significant “long” equity positions.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Short Sales Risk. The Fund may make short sales of securities, which means it may experience a loss if the market price of the security increases between the date of the short sale and the date the security is replaced. Short sales may reduce the Fund’s returns or increase volatility.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Non-Diversification Risk. The Fund can invest a larger portion of its assets in the stocks of a limited number of companies than a diversified fund, which means it may have more exposure to the price movements of a single security or small group of securities than funds that diversify their investments among many companies.
Value Investing Risk. Value investing attempts to identify strong companies whose stocks are selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Interest Rate Risk. Interest rate risk is the risk that a debt security’s value will decline due to changes in market interest rates. Even though some interest-bearing securities offer a stable stream of income, their prices will fluctuate with changes in interest rates.
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. Credit risk is affected by the issuer’s credit status, and is generally higher for non-investment grade securities.
Non-Investment Grade Securities Risk. Non-investment grade securities (also known as “high yield” or “junk bonds”), those rated below investment grade by the primary rating agencies (e.g., below BB/Ba by S&P/Moody’s), tend to have more volatile prices and increased price sensitivity to changing interest rates and adverse economic and business developments than investment grade securities. In addition, compared to investments in investment grade securities, investments in non-investment grade securities are subject to greater risk of loss due to default or decline in credit quality. There is a greater likelihood that adverse economic or company-specific events will make the issuer unable to make interest and/or principal payments, and more susceptible to negative market sentiment, leading to depressed prices and decreased liquidity.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in price and supply of energy fuels, energy conservation, supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Information Technology Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Portfolio Turnover Rate. The Fund’s portfolio turnover rate is expected to exceed 200%. This type of Fund has a high portfolio turnover that necessarily results in greater transaction costs and causes more short-term capital gains (or losses) to be realized. Distributions to shareholders of short-term capital gains are taxed as ordinary income under federal income tax laws.

HISTORICAL PERFORMANCE

The Fund commenced operations on December 15, 2008, upon the reorganization of the 1st Source Monogram Long/Short Fund, the Fund’s predecessor fund (the “Predecessor Fund”), into the Fund. With the reorganization, the Fund assumed the financial and performance history of the Predecessor Fund. The following tables provide an indication of the historical risk of an investment in the Fund (and Predecessor Fund for periods prior to December 15, 2008). The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to that of a broad-based securities market index and an additional comparison index. Past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. In addition, the Predecessor Fund was advised by a different investment advisor and subject to different expenses, which may have produced different investment results. The portfolio managers of the Fund, however, were also the portfolio managers of the Predecessor Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH LONG/SHORT FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/09	16.00%
Worst — 12/31/08	-15.94%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Investor Class	1 Year	5 Years	Since Inception	Inception Date
Wasatch Long/Short Fund	8.67%	4.47%	6.00%	Aug. 01, 2003
Wasatch Long/Short Fund Return after taxes on distributions	8.63%	4.25%	5.23%	Aug. 01, 2003
Wasatch Long/Short Fund Return after taxes on distributions and sale of Fund shares	5.69%	3.70%	4.76%	Aug. 01, 2003
Wasatch Long/Short Fund S&P 500 Index (reflects no deductions for fees, expenses or taxes)	16.00%	1.66%	6.10%	Aug. 01, 2003
Wasatch Long/Short Fund Citigroup Three Month U.S. Treasury Bills Index (reflects no deductions for fees, expenses or taxes)	0.07%	0.45%	1.72%	Aug. 01, 2003

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Dividends on short sales are the dividends paid to the lenders of borrowed securities. The expenses related to dividends on short sales are estimated and will vary depending on whether the securities the Fund sells short pay dividends and on the amount of any such dividends. Expenses also include borrowing costs paid to the broker in connection with borrowing the security to be sold short. The rate paid by brokers varies by security.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Wasatch Global Opportunities Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH GLOBAL OPPORTUNITIES FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 38% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

38.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in small and micro cap foreign and domestic companies.
Under normal market conditions, we will invest the Fund’s assets in equity securities (including common stock, preferred stock and securities convertible into common stock) of foreign and domestic companies with market capitalizations of less than US$5 billion at the time of purchase. The Fund may invest a significant portion of its total assets (up to 35% under normal market conditions) in securities of companies with market capitalizations greater than US$5 billion at the time of purchase when the companies meet our investment criteria. The Fund may also invest a significant portion of its total assets in micro cap companies with market capitalizations below US$1 billion (up to 90% under normal market conditions).
The Fund will typically invest in securities issued by companies domiciled in at least three countries, including the United States. The Fund may invest a significant portion of its total assets in companies domiciled in foreign countries (up to 80% under normal market conditions). Securities issued by foreign companies incorporated outside the United States whose securities are publicly traded in the United States are not defined as “foreign companies” and are not subject to this limitation.
The Fund may invest a significant amount of its total assets (5% to 50% under normal market conditions) at the time of purchase in securities issued by companies domiciled in emerging markets. Emerging market countries are those currently included in the Morgan Stanley Capital International (MSCI) EFM (Emerging + Frontier Markets) Index. These companies typically are located in the Asia-Pacific region, Eastern Europe, the Middle East, Central and South America, and Africa.
We use a process of quantitative screening followed by “bottom up” fundamental analysis to identify individual companies that we believe are the World’s Best Growth Companies.^® We travel extensively to visit companies and expect to meet with senior management.
We may also invest in growth companies that we believe have had a temporary setback and therefore have appealing valuation relative to their long-term growth potential.
At times, we may invest in early stage companies with limited or no earnings history if we believe they have outstanding long-term growth potential. We may also invest in initial public offerings (IPOs).
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries. We may significantly shift Fund assets between asset classes, sectors, and geographic regions based on where we believe the best growth opportunities and valuations currently exist. The Fund may invest a large percentage of its assets in a few regions or sectors, including industrials, information technology, consumer discretionary, health care, financials, materials and energy.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Region Risk. Social, political and economic conditions and changes in regulatory, tax, or economic policy in a country or region could significantly affect the market in that country or region. In addition, global economies and financial markets are becoming increasingly interconnected, which increases the possibility that conditions in one country or region might adversely impact the issuers of securities in a different country or region. From time to time, a small number of companies and industries may represent a large portion of the market in a particular country or region, and these companies and industries can be sensitive to adverse social, political, economic, or regulatory developments.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap and Small Company Stock Risk. Micro cap and small company stocks may be very sensitive to changing economic conditions and market downturns.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Value Investing Risk. Value investing attempts to identify strong companies whose stocks are selling at a discount from their perceived true worth, and is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide information on how the Investor Class of the Fund has performed over time.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH GLOBAL OPPORTUNITIES FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/09	32.73%
Worst — 9/30/11	-18.94%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch Global Opportunities Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.50%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.34%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.84%

^[1]

1 Year

rr_ExpenseExampleYear01

187

3 Years

rr_ExpenseExampleYear03

579

5 Years

rr_ExpenseExampleYear05

996

10 Years

rr_ExpenseExampleYear10

2,158

2009

rr_AnnualReturn2009

61.36%

2010

rr_AnnualReturn2010

26.31%

2011

rr_AnnualReturn2011

(8.87%)

2012

rr_AnnualReturn2012

25.50%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

32.73%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(18.94%)

1 Year

rr_AverageAnnualReturnYear01

25.50%

Since Inception

rr_AverageAnnualReturnSinceInception

26.07%

Inception Date

rr_AverageAnnualReturnInceptionDate

Nov. 17, 2008

Wasatch Global Opportunities Fund | Return after taxes on distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

23.40%

Since Inception

rr_AverageAnnualReturnSinceInception

24.64%

Inception Date

rr_AverageAnnualReturnInceptionDate

Nov. 17, 2008

Wasatch Global Opportunities Fund | Return after taxes on distributions and sale of Fund shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

19.34%

Since Inception

rr_AverageAnnualReturnSinceInception

22.83%

Inception Date

rr_AverageAnnualReturnInceptionDate

Nov. 17, 2008

Wasatch Global Opportunities Fund | MSCI All Country (AC) World Small Cap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

18.06%

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

20.34%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Nov. 17, 2008

^[2]

Wasatch Global Opportunities Fund | S&P Global SmallCap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

19.08%

Since Inception

rr_AverageAnnualReturnSinceInception

19.44%

Inception Date

rr_AverageAnnualReturnInceptionDate

Nov. 17, 2008

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.95% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). There were no reimbursements for the Investor Class shares of the Fund during 2012. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

[2] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

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Wasatch International Opportunities Fund

WASATCH INTERNATIONAL OPPORTUNITIES FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Wasatch International Opportunities Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Wasatch International Opportunities Fund Investor Class Shares
Management Fee		1.95%
Distribution/Service (12b-1) Fee		none
Other Expenses		0.53%
Total Annual Fund Operating Expenses	[1]	2.48%
Expense Reimbursement		(0.23%)
Total Annual Fund Operating Expenses After Expense Reimbursement		2.25%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Wasatch International Opportunities Fund Investor Class	228	751	1,300	2,799

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 41% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in foreign micro cap companies.
Under normal market conditions, we will invest the Fund’s assets in equity securities of foreign companies with market capitalizations of less than US$1 billion at the time of purchase. Under normal market conditions, the Fund will invest in at least five of the countries included in the Morgan Stanley Capital International (MSCI) All Country (AC) World Ex-U.S.A. Small Cap Index.
The Fund may invest a significant amount of its total assets (20% to 70% under normal market conditions) at the time of purchase in securities issued by companies domiciled in emerging markets. Emerging market countries are those currently included in the MSCI EFM (Emerging Frontier Markets) Index. These companies typically are located in the Asia-Pacific region, Eastern Europe, the Middle East, Central and South America, and Africa.
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 may invest in early stage companies if we believe they have outstanding long-term 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 in a few sectors, including industrials, consumer discretionary, information technology, materials, consumer staples, energy, financials and health care.
The Fund may also invest in initial public offerings (IPOs).

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap Company Stock Risk. Micro cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH INTERNATIONAL OPPORTUNITIES FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/09	44.35%
Worst — 9/30/08	-27.60%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Wasatch International Opportunities Fund		1 Year	5 Years	Since Inception	Inception Date
Investor Class		31.79%	2.04%	9.20%	Jan. 27, 2005
Investor Class Return after taxes on distributions		31.79%	1.49%	8.09%	Jan. 27, 2005
Investor Class Return after taxes on distributions and sale of Fund shares		20.67%	1.59%	7.74%	Jan. 27, 2005
MSCI AC World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)	[1]	18.52%	(0.39%)	6.76%	Jan. 27, 2005
MSCI World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)	[1]	17.48%	(0.70%)	5.00%	Jan. 27, 2005

After tax-returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 2.25% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

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Wasatch Ultra Growth Fund

WASATCH ULTRA GROWTH FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s primary investment objective is long-term growth of capital.

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Wasatch Ultra Growth Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Wasatch Ultra Growth Fund Investor Class Shares
Management Fee		1.00%
Distribution/Service (12b-1) Fee		none
Other Expenses		0.32%
Acquired Fund Fees and Expenses		0.20%
Total Annual Fund Operating Expenses	[1]	1.52%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Wasatch Ultra Growth Fund Investor Class	155	481	831	1,817

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 43% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in smaller high growth companies.
Under normal market conditions, we will invest the Fund’s assets in the equity securities of rapidly growing companies. These companies are usually small to mid-size with market capitalizations of less than $5 billion at the time of purchase.
The Fund may invest up to 30% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly traded in the United States are not defined as foreign companies and are not subject to this limitation.
We use a process of “bottom up” fundamental analysis to look for individual companies that we believe have above average potential for rapid earnings growth and stock price appreciation. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
The Fund may invest a large percentage of its assets in a few sectors, including information technology, financials, health care, consumer discretionary and industrials.
The Fund may invest in initial public offerings (IPOs).

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH ULTRA GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/03	29.29%
Worst — 12/31/08	-31.56%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Wasatch Ultra Growth Fund	1 Year	5 Years	10 Years
Investor Class	12.45%	(0.01%)	6.25%
Investor Class Return after taxes on distributions	10.16%	(0.59%)	5.21%
Investor Class Return after taxes on distributions and sale of Fund shares	11.10%	(0.03%)	5.29%
Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)	14.59%	3.49%	9.80%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). Acquired Fund Fees and Expenses are not included in the expense limitation. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date. There were no reimbursements for the Investor Class shares of the Fund during 2012. The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund's most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Wasatch Heritage Growth Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH HERITAGE GROWTH FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s primary investment objective is long-term growth of capital.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 26% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

26.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in growing mid cap companies at reasonable prices.
Under normal market conditions, the Fund will invest in the equity securities of growing companies with market capitalizations of between $2.5 billion and $15 billion at the time of purchase.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are publicly 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, and we use a process of “bottom up” fundamental analysis to look for individual companies that we believe are stable and have the potential to grow steadily for long periods of time. 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 may invest a large percentage of its assets in a few sectors, including information technology, industrials, consumer discretionary, financials, health care and energy.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide information on how the Investor Class of the Fund has performed over time.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH HERITAGE GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/09	17.91%
Worst — 12/31/08	-23.31%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch Heritage Growth Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

0.70%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.33%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.03%

^[1]

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.08%)

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

0.95%

1 Year

rr_ExpenseExampleYear01

97

3 Years

rr_ExpenseExampleYear03

320

5 Years

rr_ExpenseExampleYear05

561

10 Years

rr_ExpenseExampleYear10

1,253

2005

rr_AnnualReturn2005

4.58%

2006

rr_AnnualReturn2006

6.01%

2007

rr_AnnualReturn2007

3.85%

2008

rr_AnnualReturn2008

(37.60%)

2009

rr_AnnualReturn2009

43.06%

2010

rr_AnnualReturn2010

21.67%

2011

rr_AnnualReturn2011

2.44%

2012

rr_AnnualReturn2012

9.45%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

17.91%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(23.31%)

1 Year

rr_AverageAnnualReturnYear01

9.45%

5 Years

rr_AverageAnnualReturnYear05

4.02%

Since Inception

rr_AverageAnnualReturnSinceInception

5.37%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 18, 2004

Wasatch Heritage Growth Fund | Return after taxes on distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.75%

5 Years

rr_AverageAnnualReturnYear05

3.75%

Since Inception

rr_AverageAnnualReturnSinceInception

4.89%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 18, 2004

Wasatch Heritage Growth Fund | Return after taxes on distributions and sale of Fund shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

7.07%

5 Years

rr_AverageAnnualReturnYear05

3.40%

Since Inception

rr_AverageAnnualReturnSinceInception

4.56%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 18, 2004

Wasatch Heritage Growth Fund | Russell Midcap® Growth Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

15.81%

5 Years

rr_AverageAnnualReturnYear05

3.23%

Since Inception

rr_AverageAnnualReturnSinceInception

7.14%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 18, 2004

Wasatch Heritage Growth Fund | S&P 500 Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

16.00%

5 Years

rr_AverageAnnualReturnYear05

1.66%

Since Inception

rr_AverageAnnualReturnSinceInception

4.90%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 18, 2004

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 0.95% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	WASATCH FUNDS TRUST
Prospectus Date	rr_ProspectusDate	Jan. 31, 2013
Document Creation Date	dei_DocumentCreationDate	Jan. 28, 2013

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Wasatch Long/Short Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Dividend Expense on Short Sales/Interest Expense

rr_Component1OtherExpensesOverAssets

0.24%

^[1]

Investor Class | Wasatch Long/Short Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH LONG/SHORT FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is capital appreciation.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 71% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

71.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in equity securities by maintaining long equity positions and short equity positions.
We seek to achieve higher risk-adjusted returns with lower volatility compared to the equity markets in general (as represented by the S&P 500 Index). Under normal market conditions, we will invest the Fund’s assets in the equity securities of companies with market capitalizations of at least $100 million at the time of purchase that we have identified as being undervalued (long equity positions) and we will sell short those securities (short equity positions) that we have identified as being overvalued. The equity securities in which the Fund invests include common stocks, preferred stocks, securities convertible into or exchangeable for common stocks, warrants and any rights to purchase common stocks and other securities with equity characteristics.
The Fund may at any time have either a net long exposure or a net short exposure to the equity markets and the Fund will not be managed to maintain either net long or net short market exposure.
The Fund may invest in early stage companies and initial public offerings (IPOs).
We believe that the best opportunities to make both short and long equity investments are when the market’s perception of the values of individual companies (measured by the stock price) differs widely from our assessment of the intrinsic values of such companies. We further believe that opportunities to invest in undervalued and overvalued stocks arise due to a variety of market inefficiencies including:

• Changes in market participant psychology and circumstances.
• Imperfect information.
• Forecasts and projections by Wall Street analysts and company representatives that differ from experienced reality.

When evaluating a potential long or short investment for the Fund, we employ a comprehensive valuation analysis intended to establish a range for fair valuation or intrinsic company value, with particular emphasis on company fundamentals.
Along with long positions, the Long/Short Fund intends to engage in short sales of securities of companies that we believe:

• Have earnings that appear to be reflected in the current price.
• Are likely to fall short of market expectations.
• Are in industries exhibiting weaknesses.
• Have poor management.
• Are likely to suffer an event affecting long-term earnings.

The Fund may invest in fixed income securities of any maturity consisting of corporate notes, bonds and debentures, including those that are rated less than investment grade at the time of purchase.
The Fund is non-diversified meaning that it can concentrate investments in a more limited number of issuers than a diversified fund.
The Fund may invest a large percentage of its assets in a few sectors, including information technology, financials, energy, consumer discretionary, materials, industrials and consumer staples.
The Fund is expected to have a high portfolio turnover rate.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Market Direction Risk. Since the Fund has both a “long” and a “short” portfolio, an investment in the Fund will involve market risks associated with different types of investment decisions than those made for a typical “long only” stock fund. The Fund’s results will suffer both when there is a general stock market advance and the Fund holds significant “short” equity positions, or when there is a general stock market decline and the Fund holds significant “long” equity positions.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Short Sales Risk. The Fund may make short sales of securities, which means it may experience a loss if the market price of the security increases between the date of the short sale and the date the security is replaced. Short sales may reduce the Fund’s returns or increase volatility.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Non-Diversification Risk. The Fund can invest a larger portion of its assets in the stocks of a limited number of companies than a diversified fund, which means it may have more exposure to the price movements of a single security or small group of securities than funds that diversify their investments among many companies.
Value Investing Risk. Value investing attempts to identify strong companies whose stocks are selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Interest Rate Risk. Interest rate risk is the risk that a debt security’s value will decline due to changes in market interest rates. Even though some interest-bearing securities offer a stable stream of income, their prices will fluctuate with changes in interest rates.
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. Credit risk is affected by the issuer’s credit status, and is generally higher for non-investment grade securities.
Non-Investment Grade Securities Risk. Non-investment grade securities (also known as “high yield” or “junk bonds”), those rated below investment grade by the primary rating agencies (e.g., below BB/Ba by S&P/Moody’s), tend to have more volatile prices and increased price sensitivity to changing interest rates and adverse economic and business developments than investment grade securities. In addition, compared to investments in investment grade securities, investments in non-investment grade securities are subject to greater risk of loss due to default or decline in credit quality. There is a greater likelihood that adverse economic or company-specific events will make the issuer unable to make interest and/or principal payments, and more susceptible to negative market sentiment, leading to depressed prices and decreased liquidity.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in price and supply of energy fuels, energy conservation, supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Information Technology Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Portfolio Turnover Rate. The Fund’s portfolio turnover rate is expected to exceed 200%. This type of Fund has a high portfolio turnover that necessarily results in greater transaction costs and causes more short-term capital gains (or losses) to be realized. Distributions to shareholders of short-term capital gains are taxed as ordinary income under federal income tax laws.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Nondiversified Status [Text]

rr_RiskNondiversifiedStatus

Non-Diversification Risk. The Fund can invest a larger portion of its assets in the stocks of a limited number of companies than a diversified fund, which means it may have more exposure to the price movements of a single security or small group of securities than funds that diversify their investments among many companies.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Fund commenced operations on December 15, 2008, upon the reorganization of the 1st Source Monogram Long/Short Fund, the Fund’s predecessor fund (the “Predecessor Fund”), into the Fund. With the reorganization, the Fund assumed the financial and performance history of the Predecessor Fund. The following tables provide an indication of the historical risk of an investment in the Fund (and Predecessor Fund for periods prior to December 15, 2008). The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to that of a broad-based securities market index and an additional comparison index. Past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. In addition, the Predecessor Fund was advised by a different investment advisor and subject to different expenses, which may have produced different investment results. The portfolio managers of the Fund, however, were also the portfolio managers of the Predecessor Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide an indication of the historical risk of an investment in the Fund (and Predecessor Fund for periods prior to December 15, 2008). The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to that of a broad-based securities market index and an additional comparison index.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH LONG/SHORT FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/09	16.00%
Worst — 12/31/08	-15.94%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Investor Class | Wasatch Long/Short Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.10%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.17%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.51%

1 Year

rr_ExpenseExampleYear01

154

3 Years

rr_ExpenseExampleYear03

478

5 Years

rr_ExpenseExampleYear05

824

10 Years

rr_ExpenseExampleYear10

1,801

2004

rr_AnnualReturn2004

4.47%

2005

rr_AnnualReturn2005

3.82%

2006

rr_AnnualReturn2006

14.72%

2007

rr_AnnualReturn2007

4.98%

2008

rr_AnnualReturn2008

(20.93%)

2009

rr_AnnualReturn2009

30.07%

2010

rr_AnnualReturn2010

9.41%

2011

rr_AnnualReturn2011

1.77%

2012

rr_AnnualReturn2012

8.67%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

16.00%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(15.94%)

1 Year

rr_AverageAnnualReturnYear01

8.67%

5 Years

rr_AverageAnnualReturnYear05

4.47%

Since Inception

rr_AverageAnnualReturnSinceInception

6.00%

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 01, 2003

Investor Class | Wasatch Long/Short Fund | Return after taxes on distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.63%

5 Years

rr_AverageAnnualReturnYear05

4.25%

Since Inception

rr_AverageAnnualReturnSinceInception

5.23%

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 01, 2003

Investor Class | Wasatch Long/Short Fund | Return after taxes on distributions and sale of Fund shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.69%

5 Years

rr_AverageAnnualReturnYear05

3.70%

Since Inception

rr_AverageAnnualReturnSinceInception

4.76%

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 01, 2003

Investor Class | Wasatch Long/Short Fund | S&P 500 Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

16.00%

5 Years

rr_AverageAnnualReturnYear05

1.66%

Since Inception

rr_AverageAnnualReturnSinceInception

6.10%

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 01, 2003

Investor Class | Wasatch Long/Short Fund | Citigroup Three Month U.S. Treasury Bills Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

0.07%

5 Years

rr_AverageAnnualReturnYear05

0.45%

Since Inception

rr_AverageAnnualReturnSinceInception

1.72%

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 01, 2003

[1] Dividends on short sales are the dividends paid to the lenders of borrowed securities. The expenses related to dividends on short sales are estimated and will vary depending on whether the securities the Fund sells short pay dividends and on the amount of any such dividends. Expenses also include borrowing costs paid to the broker in connection with borrowing the security to be sold short. The rate paid by brokers varies by security.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	WASATCH FUNDS TRUST
Prospectus Date	rr_ProspectusDate	Jan. 31, 2013
Wasatch Frontier Emerging Small Countries Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	WASATCH FRONTIER EMERGING SMALL COUNTRIES FUND — Summary
Objective [Heading]	rr_ObjectiveHeading	INVESTMENT OBJECTIVE
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund’s investment objective is long-term growth of capital.
Expense [Heading]	rr_ExpenseHeading	FEES AND EXPENSES OF THE FUND
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	SHAREHOLDER FEES (fees paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	January 31, 2014
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	PORTFOLIO TURNOVER
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance.
Other Expenses, New Fund, Based on Estimates [Text]	rr_OtherExpensesNewFundBasedOnEstimates	Other Expenses are based on estimated expenses for the Fund’s first full fiscal year.
Expense Example [Heading]	rr_ExpenseExampleHeading	EXAMPLE
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	PRINCIPAL STRATEGIES
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund invests primarily in the equity securities of companies of all market capitalizations that are tied economically to frontier markets and small emerging market countries. Under normal market conditions, we will invest at least 80% of the Fund’s assets in the equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights and other securities with equity characteristics) of companies that are tied economically to frontier markets and small emerging market countries. “Frontier markets” include any country that is outside the Morgan Stanley Capital International (MSCI) All Country World Index, and also any country that is currently included in the Russell Frontier Index, the S&P Frontier Broad Market Index (BMI), the MSCI Frontier Markets Index, or similar market indices, or that, in our opinion, have similar characteristics regardless of their inclusion in an index. “Emerging markets” include those countries currently considered to be developing as per their inclusion in the MSCI Emerging Markets Index. We consider a “small emerging market country” to be any country that individually constitutes not more than 7% of the MSCI Emerging Markets Index or the S&P Emerging BMI. We will generally consider qualifying investments to be in companies that are listed on an exchange in a frontier market or small emerging market country, that are legally domiciled in a frontier market or small emerging market country, that have at least 50% of their assets in a frontier market or small emerging market country, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services provided in a frontier market or small emerging market country. The Fund will not be required to sell a security because the market to which it is economically tied is no longer what we consider to be a frontier market or a small emerging market country. In general, frontier markets and small emerging market countries, with the exception of the oil-producing Persian Gulf States, tend to have relatively low gross national product per capita compared to the larger traditionally-recognized emerging markets and the world’s major developed economies. Frontier and small emerging market countries include the least developed markets even by emerging market standards. We believe frontier markets and small emerging market countries offer investment opportunities that arise from long-term trends in demographics, deregulation, offshore outsourcing and improving corporate governance. The Fund may invest in the equity securities of companies of any size, although we expect a significant portion of the Fund’s assets to be invested in the equity securities of companies under US$3 billion at the time of purchase. We travel extensively outside 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 with the goal of owning the highest quality growth companies tied economically to frontier markets and small emerging market countries. 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 in a few sectors, including financials. We may also invest in initial public offerings (IPOs). The Fund is non-diversified, meaning that it can concentrate investments in a more limited number of issuers than a diversified fund.
Risk [Heading]	rr_RiskHeading	PRINCIPAL RISKS
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. The Fund is subject to the following principal investment risks: Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market. Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline. Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investment in U.S. securities due to differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates. Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies. Frontier Markets Risk. In addition to the risks of investing in foreign securities and emerging markets, frontier market securities involve unique risks, such as exposure to economies less diverse and mature than those of the U.S. or more established foreign markets. Economic or political instability may cause larger price changes in frontier market securities than in securities of issuers based in more developed foreign countries, including securities of issuers in larger emerging markets. Frontier markets generally receive less investor attention than developed markets and larger emerging markets. These risks can result in the potential for extreme price volatility and illiquidity. Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns. Growth Stock Risk. Growth stock prices may be more sensitive to changes in current or expected earnings than the prices of other stocks, and they may fall or not appreciate in step with the broader securities markets. Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information. Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition. Liquidity Risk. From time to time, the trading market for a particular security or type of security in which the Fund invests may become less liquid or even illiquid. Reduced liquidity will have an adverse impact on the Fund’s ability to sell such securities when necessary to meet the Fund’s liquidity needs or in response to a specific economic event. Market quotations for such securities may be volatile. Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors. Non-Diversification Risk. The Fund can invest a larger portion of its assets in the stocks of a limited number of companies than a diversified fund, which means it may have more exposure to the price movements of a single security or small group of securities than funds that diversify their investments among many companies.
Risk Lose Money [Text]	rr_RiskLoseMoney	All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	Non-Diversification Risk. The Fund can invest a larger portion of its assets in the stocks of a limited number of companies than a diversified fund, which means it may have more exposure to the price movements of a single security or small group of securities than funds that diversify their investments among many companies.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	PERFORMANCE
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	Ordinarily, this section of the prospectus contains information that would allow you to evaluate the performance of the Fund’s Investor Class using several different measures such as yearly changes in performance, best and worst quarterly returns and average annual total returns before and after taxes compared to a relevant benchmark. However, the Wasatch Frontier Emerging Small Countries Fund commenced operations on January 31, 2012 and does not have a full calendar year of performance.
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	Ordinarily, this section of the prospectus contains information that would allow you to evaluate the performance of the Fund’s Investor Class using several different measures such as yearly changes in performance, best and worst quarterly returns and average annual total returns before and after taxes compared to a relevant benchmark. However, the Wasatch Frontier Emerging Small Countries Fund commenced operations on January 31, 2012 and does not have a full calendar year of performance.
Wasatch Frontier Emerging Small Countries Fund | Investor Class Shares
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Redemption Fee (as a % of amount redeemed on shares held 90 days or less)	rr_RedemptionFeeOverRedemption	2.00%
Exchange Fee	rr_ExchangeFeeOverRedemption	none
Maximum Account Fee	rr_MaximumAccountFeeOverAssets	none
Management Fee	rr_ManagementFeesOverAssets	1.75%
Distribution/Service (12b-1) Fee	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	1.89%	[1]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	3.64%	[1]
Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(1.39%)
Total Annual Fund Operating Expenses After Expense Reimbursement	rr_NetExpensesOverAssets	2.25%
1 Year	rr_ExpenseExampleYear01	228
3 Years	rr_ExpenseExampleYear03	987
5 Years	rr_ExpenseExampleYear05	1,766
10 Years	rr_ExpenseExampleYear10	3,809

[1] Other Expenses are based on estimated expenses for the Fund's first full fiscal year. The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 2.25% (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses) until at least January 31, 2014. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2013

Wasatch Long/Short Fund | Investor Class

Risk/Return:

rr_RiskReturnAbstract

Component1 Other Expenses

rr_Component1OtherExpensesOverAssets

0.24%

^[1]

Institutional Class | Wasatch Long/Short Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH LONG/SHORT FUND — Summary

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is capital appreciation.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 71% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

71.00%

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

Other Expenses for Institutional Class shares are estimated based on actual expenses for the Investor Class shares of the Fund during the most recent fiscal year.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that the Fund’s operating expenses (as a percentage of net assets) remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in equity securities by maintaining long equity positions and short equity positions.
We seek to achieve higher risk-adjusted returns with lower volatility compared to the equity markets in general (as represented by the S&P 500 Index). Under normal market conditions, we will invest the Fund’s assets in the equity securities of companies with market capitalizations of at least $100 million at the time of purchase that we have identified as being undervalued (long equity positions) and we will sell short those securities (short equity positions) that we have identified as being overvalued. The equity securities in which the Fund invests include common stocks, preferred stocks, securities convertible into or exchangeable for common stocks, warrants and any rights to purchase common stocks.
The Fund may at any time have either a net long exposure or a net short exposure to the equity markets and the Fund will not be managed to maintain either net long or net short market exposure.
The Fund may invest in early stage companies and initial public offerings (IPOs).
We believe that the best opportunities to make both short and long equity investments are when the market’s perception of the values of individual companies (measured by the stock price) differs widely from our assessment of the intrinsic values of such companies. We further believe that opportunities to invest in undervalued and overvalued stocks arise due to a variety of market inefficiencies including:

• Changes in market participant psychology and circumstances.
• Imperfect information.
• Forecasts and projections by Wall Street analysts and company representatives that differ from experienced reality.
  When evaluating a potential long or short investment for the Fund, we employ a comprehensive valuation analysis intended to establish a range for fair valuation or intrinsic company value, with particular emphasis on company fundamentals.
  Along with long positions, the Long/Short Fund intends to engage in short sales of securities of companies that we believe:
• Have earnings that appear to be reflected in the current price.
• Are likely to fall short of market expectations.
• Are in industries exhibiting weaknesses.
• Have poor management.
• Are likely to suffer an event affecting long-term earnings.
  The Fund may invest in fixed income securities of any maturity consisting of corporate notes, bonds and debentures, including those that are rated less than investment grade at the time of purchase.
  The Fund is non-diversified, meaning that it can concentrate investments in a more limited number of issuers than a diversified fund.
  The Fund may invest a large percentage of its assets in a few sectors, including information technology, financials, energy, consumer discretionary, materials, industrials and consumer staples.
  The Fund is expected to have a high portfolio turnover rate.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Market Direction Risk. Since the Fund has both a “long” and a “short” portfolio, an investment in the Fund will involve market risks associated with different types of investment decisions than those made for a typical “long only” stock fund. The Fund’s results will suffer both when there is a general stock market advance and the Fund holds significant “short” equity positions, or when there is a general stock market decline and the Fund holds significant “long” equity positions.
Stock Selection Risk. The Fund invests primarily in equity securities (including common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics). The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Short Sales Risk. The Fund may make short sales of securities, which means it may experience a loss if the market price of the security increases between the date of the short sale and the date the security is replaced. Short sales may reduce the Fund’s returns or increase volatility.
Small Company Stock Risk. Small cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets, fewer product lines, and limited managerial and financial resources, resulting in volatile stock prices and a limited ability to sell them at a desirable time or price.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Non-Diversification Risk. The Fund can invest a larger portion of its assets in the stocks of a limited number of companies than a diversified fund, which means it may have more exposure to the price movements of a single security or small group of securities than funds that diversify their investments among many companies.
Value Investing Risk. Value investing attempts to identify strong companies whose stocks are selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Interest Rate Risk. Interest rate risk is the risk that a debt security’s value will decline due to changes in market interest rates. Even though some interest-bearing securities offer a stable stream of income, their prices will fluctuate with changes in interest rates.
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. Credit risk is affected by the issuer’s credit status, and is generally higher for non-investment grade securities.
Non-Investment Grade Securities Risk. Non-investment grade securities (also known as “junk bonds”), those rated below investment grade by the primary rating agencies (e.g., below BB/Ba by S&P/Moody’s), tend to have more volatile prices and increased price sensitivity to changing interest rates and adverse economic and business developments than investment grade securities. In addition, compared to investments in investment grade securities, investments in non-investment grade securities are subject to greater risk of loss due to default or decline in credit quality. There is a greater likelihood that adverse economic or company-specific events will make the issuer unable to make interest and/or principal payments, and more susceptible to negative market sentiment, leading to depressed prices and decreased liquidity.
Sector Weightings Risk. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors it may have increased exposure to the price movements of those sectors.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in price and supply of energy fuels, energy conservation, supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Information Technology Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Portfolio Turnover Rate. The Fund’s portfolio turnover rate is expected to exceed 200%. This type of Fund has a high portfolio turnover that necessarily results in greater transaction costs and causes more short-term capital gains (or losses) to be realized. Distributions to shareholders of short-term capital gains are taxed as ordinary income under federal income tax laws.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Nondiversified Status [Text]

rr_RiskNondiversifiedStatus

Non-Diversification Risk. The Fund can invest a larger portion of its assets in the stocks of a limited number of companies than a diversified fund, which means it may have more exposure to the price movements of a single security or small group of securities than funds that diversify their investments among many companies.

Bar Chart and Performance Table [Heading]

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HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

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The Fund’s Investor Class shares commenced operations on December 15, 2008, upon the reorganization of the 1st Source Monogram Long/Short Fund, the Fund’s predecessor fund (the “Predecessor Fund”), into the Fund. With the reorganization, the Fund assumed the financial and performance history of the Predecessor Fund. The following tables provide an indication of the historical risk of an investment in the Fund (and Predecessor Fund for periods prior to December 15, 2008) as represented by the Fund’s Investor Class. Institutional Class shares are new and do not have any performance history. The annual returns in the bar chart, the best and worst quarterly returns and the Average Annual Total Returns table below are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year-to-year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance, as represented by the Fund’s Investor Class, over the time periods indicated to that of a broad-based securities market index composed of securities similar to those held by the Fund and an additional index. Past performance, before and after taxes, is not necessarily an indication of how the Institutional Class of the Fund will perform in the future. In addition, the Predecessor Fund was advised by a different investment advisor and subject to different expenses, which may have produced different investment results. The portfolio managers of the Fund, however, were also the portfolio managers of the Predecessor Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following tables provide an indication of the historical risk of an investment in the Fund (and Predecessor Fund for periods prior to December 15, 2008) as represented by the Fund’s Investor Class. Institutional Class shares are new and do not have any performance history. The annual returns in the bar chart, the best and worst quarterly returns and the Average Annual Total Returns table below are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year-to-year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance, as represented by the Fund’s Investor Class, over the time periods indicated to that of a broad-based securities market index composed of securities similar to those held by the Fund and an additional index.

Performance Availability Website Address [Text]

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www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

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Past performance, before and after taxes, is not necessarily an indication of how the Institutional Class of the Fund will perform in the future.

Bar Chart [Heading]

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WASATCH LONG/SHORT FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

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Best and Worst Quarterly Returns

Best — 6/30/09	16.00%
Worst — 12/31/08	-15.94%

Bar Chart, Returns for Class Not Offered in Prospectus [Text]

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Institutional Class shares are new and do not have any performance history. The annual returns in the bar chart, the best and worst quarterly returns and the Average Annual Total Returns table below are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses.

Performance Table Heading

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Average Annual Total Returns — (as of 12/31/12)

Performance Table Uses Highest Federal Rate

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After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

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The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

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The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

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After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Institutional Class | Wasatch Long/Short Fund | Institutional Class Shares

Risk/Return:

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Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

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none

Maximum Account Fee

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none

Management Fee

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1.10%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Dividend Expense on Short Sales/Interest Expense

rr_Component3OtherExpensesOverAssets

0.24%

^[1]

Other Expenses

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0.10%

^[2]

Total Annual Fund Operating Expenses

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1.44%

^[2]

Expense Reimbursement

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(0.03%)

Total Annual Fund Operating Expenses after Expense Reimbursement

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1.41%

1 Year

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144

3 Years

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453

5 Years

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785

10 Years

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1,723

Institutional Class | Wasatch Long/Short Fund | Investor Class

Risk/Return:

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2004

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4.47%

2005

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3.82%

2006

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14.72%

2007

rr_AnnualReturn2007

4.98%

2008

rr_AnnualReturn2008

(20.93%)

2009

rr_AnnualReturn2009

30.07%

2010

rr_AnnualReturn2010

9.41%

2011

rr_AnnualReturn2011

1.77%

2012

rr_AnnualReturn2012

8.67%

Highest Quarterly Return, Label

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Best

Highest Quarterly Return, Date

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Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

16.00%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(15.94%)

1 Year

rr_AverageAnnualReturnYear01

8.67%

5 Years

rr_AverageAnnualReturnYear05

4.47%

Since Inception

rr_AverageAnnualReturnSinceInception

6.00%

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 01, 2003

Institutional Class | Wasatch Long/Short Fund | Return after taxes on distributions | Investor Class

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.63%

5 Years

rr_AverageAnnualReturnYear05

4.25%

Since Inception

rr_AverageAnnualReturnSinceInception

5.23%

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 01, 2003

Institutional Class | Wasatch Long/Short Fund | Return after taxes on distributions and sale of Fund shares | Investor Class

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.69%

5 Years

rr_AverageAnnualReturnYear05

3.70%

Since Inception

rr_AverageAnnualReturnSinceInception

4.76%

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 01, 2003

Institutional Class | Wasatch Long/Short Fund | S&P 500 Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

16.00%

5 Years

rr_AverageAnnualReturnYear05

1.66%

Since Inception

rr_AverageAnnualReturnSinceInception

6.10%

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 01, 2003

Institutional Class | Wasatch Long/Short Fund | Citigroup Three Month U.S. Treasury Bills Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

0.07%

5 Years

rr_AverageAnnualReturnYear05

0.45%

Since Inception

rr_AverageAnnualReturnSinceInception

1.72%

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 01, 2003

[1] Dividends on short sales are the dividends paid to the lenders of borrowed securities. The expenses related to dividends on short sales are estimated and will vary depending on whether the securities the Fund sells short pay dividends and on the amount of any such dividends. Expenses also include borrowing costs paid to the broker in connection with borrowing the security to be sold short. The rate paid by brokers varies by security.

[2] Other Expenses for Institutional Class shares are estimated based on actual expenses for the Investor Class shares of the Fund during the most recent fiscal year. Wasatch Advisors, Inc., the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.17% (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses) until at least January 31, 2014. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.

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Wasatch-Hoisington U.S. Treasury Fund

WASATCH-HOISINGTON U.S. TREASURY FUND — Summary

INVESTMENT OBJECTIVE

The Fund’s investment objective is to provide a rate of return that exceeds the rate of inflation over a business cycle by investing in U.S. Treasury securities with an emphasis on both income and capital appreciation.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	Wasatch-Hoisington U.S. Treasury Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Wasatch-Hoisington U.S. Treasury Fund Investor Class Shares
Management Fee		0.50%
Distribution/Service (12b-1) Fee		none
Other Expenses		0.22%
Total Annual Fund Operating Expenses	[1]	0.72%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. The example reflects contractual fee waivers and reimbursements through January 31, 2014. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Wasatch-Hoisington U.S. Treasury Fund Investor Class	74	231	401	896

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 13% of the average value of its portfolio.

PRINCIPAL STRATEGIES

In pursuit of the Fund’s investment objective, Hoisington Investment Management Company (HIMCO), the Fund’s Sub-Advisor will:

• Typically invest at least 90% of the Fund’s total assets in U.S. Treasury securities and in repurchase agreements collateralized by such securities.
  
• Adjust the average maturity and effective duration of the Fund’s portfolio based on HIMCO’s assessment of multi-year trends in national and international economic conditions and interest rates, changes in inflationary pressures, and the value of long term U.S. Treasury bonds (maturities longer than 20 years) relative to inflation.
  
• Invest in long-term U.S. Treasury bonds, including U.S. Treasury Strips (zero coupon Treasury securities), when HIMCO determines that economic conditions suggest lower inflation and the multi-year trend is toward decreasing interest rates.
  
• Invest in U.S. Treasury bills or notes (maturities less than five years) when HIMCO determines that economic conditions suggest rising inflation and the multi-year trend is toward increasing interest rates.
  

Over the course of a business cycle, under normal market conditions:

• The effective duration of the Fund’s holdings is expected to vary from less than a year to a maximum of 25 years.
  
• The Fund’s holdings will range in maturity from less than a year to a maximum of the longest maturity Treasury bonds available.
  
• When the Fund is invested in longer weighted average maturities it will be more sensitive to changes in market interest rates and its share price may be subject to greater volatility.
  
• The Fund’s portfolio turnover rate will vary substantially from year to year. During some periods, turnover will be well below 50%. At other times, turnover could exceed 200% annually. At these times, increased portfolio turnover may result in higher transaction costs and may also result in taxable capital gains.
  
• Portfolio adjustments may require the sale of securities prior to their maturity date. The goal of these transactions will be to increase income and/or change the duration of the overall portfolio.
  

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.
The Fund is subject to the following principal investment risks:
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. HIMCO seeks to limit credit risk by investing primarily in U.S. Treasury securities backed by the full faith and credit of the U.S. government which are viewed as carrying minimal credit risk.
Interest Rate Risk. Interest rate risk is the risk that a debt security’s value will decline due to changes in market interest rates. Even though some interest-bearing securities offer a stable stream of income, their prices will fluctuate with changes in interest rates.
Income Risk. Income risk is the potential for a decline in the Fund’s income due to falling interest rates.
Effective Duration. Effective duration is a measure of the responsiveness of a bond’s price to market interest rate changes. For example, if the interest rate increased 1%, a bond with an effective duration of five years would experience a decline in price of 5%. Similarly, if the interest rate increased 1%, the price of a bond with an effective duration of 15 years would decline 15%. At a yield of 5%, the effective duration of the longest maturity U.S. Treasury bond is about 15 years. The effective duration of the longest maturity U.S. zero coupon bond is 30 years. If the interest rate increased 1%, the value of the longest maturity zero coupon bond would decline 30%. Similarly, if the interest rate decreased 1%, the value of the longest maturity zero coupon bond would increase 30%.
Risks of Repurchase Agreements. The main risk of a repurchase agreement is that the original seller might default on its obligation to repurchase the securities. If the seller defaults, the Fund will seek to recover its investment by selling the collateral and could encounter restrictions, costs or delays. The Fund will suffer a loss if it sells the collateral for less than the repurchase price.
Risks of Zero Coupon Treasury Securities. The market prices of zero coupon securities, which do not entitle the holder to periodic interest payments, are generally more volatile than the market prices of securities of comparable quality and similar maturity that do pay interest periodically. Zero coupon securities are more sensitive to fluctuations in interest rates than non-zero coupon securities.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based bond market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH-HOISINGTON U.S. TREASURY FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 9/30/11	36.15%
Worst — 12/31/10	-11.47%

Average Annual Total Returns — (as of 12/31/12)

Average Annual Total Returns Wasatch-Hoisington U.S. Treasury Fund	1 Year	5 Years	10 Years
Investor Class	2.78%	11.28%	8.74%
Investor Class Return after taxes on distributions	1.69%	9.50%	7.10%
Investor Class Return after taxes on distributions and sale of Fund shares	2.19%	8.92%	6.72%
Barclays Capital U.S. Aggregate Bond Index (reflects no deductions for fees, expenses or taxes)	4.22%	5.95%	5.18%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Advisor has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 0.75% until at least January 31, 2014 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs and extraordinary expenses). There were no reimbursements for the Investor Class shares of the Fund during 2012. The Advisor may rescind the contractual limitation on expenses at any time after its expiration date.