485BPOS

As filed with the Securities and Exchange Commission on October 23, 2018

Securities Act File No. 33-41913

Investment Company Act File No. 811-06367

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933	☒
Pre-Effective Amendment No.	☐
Post-Effective Amendment No. 51	☒

and/or

REGISTRATION STATEMENT

UNDER

THE INVESTMENT COMPANY ACT OF 1940	☒
Amendment No. 52	☒

GABELLI EQUITY SERIES FUNDS, INC.

(Exact Name of Registrant as Specified in Charter)

One Corporate Center,

Rye, New York 10580-1422

(Address of Principal Executive Offices)

Registrant’s Telephone Number, including Area Code: 1-800-422-3554

Bruce N. Alpert

Gabelli Funds, LLC

One Corporate Center

Rye, New York 10580-1422

(Name and Address of Agent for Service)

Copies To:

Andrea R. Mango, Esq. Gabelli Investor Funds, Inc. One Corporate Center Rye, New York 10580-1422 Richard T. Prins, Esq. Skadden, Arps, Slate, Meagher & Flom LLP Four Times Square New York, New York 10036 Thomas A. DeCapo, Esq. Skadden, Arps, Slate, Meagher & Flom LLP 500 Boylston St. Boston, Massachusetts 02116

It is proposed that this filing will be effective:

☒ immediately upon filing pursuant to paragraph (b); or

☐ on [                ] pursuant to paragraph (b); or

☐ 60 days after filing pursuant to paragraph (a)(1); or

☐ on [                ] pursuant to paragraph (a)(1); or

☐ or 75 days after filing pursuant to paragraph (a)(2); or

☐ 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, GABELLI EQUITY SERIES FUNDS, INC., certifies that it meets all of the requirements for effectiveness of this Post-Effective Amendment No. 51 to its Registration Statement under Rule 485(b) under the Securities Act of 1933, as amended, and has duly caused this Post-Effective Amendment No. 51 to its Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Rye and State of New York on the 23^rd day of October 2018.

GABELLI EQUITY SERIES FUNDS, INC.
/s/ Bruce N. Alpert
By:	Bruce N. Alpert
	President

Pursuant to the requirements of the Securities Act of 1933, as amended, this Post-Effective Amendment No. 51 to its Registration Statement has been signed below by the following persons in the capacities and on the dates indicated.

Signatures	Title	Date
Mario J. Gabelli* Mario J. Gabelli	Director and Chairman of the Board	October 23, 2018
/s/ Bruce N. Alpert Bruce N. Alpert	President (Principal Executive Officer)	October 23, 2018
/s/ John C. Ball John C. Ball	Treasurer (Principal Financial Officer)	October 23, 2018
John D. Gabelli* John D. Gabelli	Director	October 23, 2018
Anthony J. Colavita* Anthony J. Colavita	Director	October 23, 2018
Vincent D. Enright* Vincent D. Enright	Director	October 23, 2018
Robert J. Morrissey* Robert J. Morrissey	Director	October 23, 2018
Kuni Nakamura* Kuni Nakamura	Director	October 23, 2018
Anthony R. Pustorino* Anthony R. Pustorino	Director	October 23, 2018
Anthonie C. van Ekris* Anthonie C. van Ekris	Director	October 23, 2018
Salvatore J. Zizza* Salvatore J. Zizza	Director	October 23, 2018

*By:	/s/ Bruce N. Alpert
	Bruce N. Alpert Attorney-in-Fact

Exhibit Index

Exhibit No.	Description
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

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Document Type	dei_DocumentType	485BPOS
Document Period End Date	dei_DocumentPeriodEndDate	Oct. 01, 2018
Registrant Name	dei_EntityRegistrantName	GABELLI EQUITY SERIES FUNDS INC
Central Index Key	dei_EntityCentralIndexKey	0000877670
Amendment Flag	dei_AmendmentFlag	false
Document Creation Date	dei_DocumentCreationDate	Oct. 01, 2018
Document Effective Date	dei_DocumentEffectiveDate	Oct. 01, 2018
Prospectus Date	rr_ProspectusDate	Oct. 01, 2018

XML

The Gabelli Global Financial Services Fund

<b>THE GABELLI GLOBAL FINANCIAL SERVICES FUND (the “Fund”) </b>

<b>Investment Objective </b>

The Fund seeks to provide capital appreciation.

<b>Fees and Expenses of the Fund: </b>

This table describes the fees and expenses that you may pay if you buy and hold the following classes of shares of the Fund. You may qualify for sales charge discounts on Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 in Class A shares of the Gabelli family of mutual funds. More information about these and other discounts is available from your financial professional and in the section entitled, “Classes of Shares” on page 18 of the prospectus and in Appendix A, “Sales Charge Reductions and Waivers Available through Certain Intermediaries,” attached to the Fund’s prospectus.

<b>Shareholder Fees</b> <br/>(fees paid directly from your investment):

Shareholder Fees - The Gabelli Global Financial Services Fund	Class AAA Shares	Class A Shares	Class C Shares	Class I Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none	5.75%	none	none
Maximum Deferred Sales Charge (Load) (as a percentage of redemption or offering price, whichever is lower)	none	none	1.00%	none
Maximum Sales Charge (Load) Imposed on Reinvested Dividends (as a percentage of amount invested)	none	none	none	none
Redemption Fees (as a percentage of amount redeemed for shares held 7 days or less)	2.00%	2.00%	2.00%	2.00%
Exchange Fee	none	none	none	none

<b>Annual Fund Operating Expenses</b><br/> (expenses that you pay each year as a percentage of the value of your investment):

Annual Fund Operating Expenses - The Gabelli Global Financial Services Fund		Class AAA Shares	Class A Shares	Class C Shares	Class I Shares
Management Fees		1.00%	1.00%	1.00%	1.00%
Distribution and Service (Rule 12b-1) Fees		0.25%	0.25%	1.00%	none
Other Expenses	[1]	1.13%	1.13%	1.13%	1.13%
Total Annual Fund Operating Expenses	[1]	2.38%	2.38%	3.13%	2.13%
Fee Waiver and/or Expense Reimbursement	[1]	(1.13%)	(1.13%)	(1.13%)	(1.13%)
Total Annual Fund Operating Expenses After Fee Wavier and/or Expense Reimbursement		1.25%	1.25%	2.00%	1.00%

<b>Expense Example</b>

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 invest $10,000 in the Fund for the time periods shown and then redeem all of your shares at the end of those periods. The example assumes a waiver of expenses through the date of the expiration of the waiver, and reflects Total Annual Fund Operating Expenses following the date of the expiration of the waiver. The example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example - The Gabelli Global Financial Services Fund - USD ($)	1 Year	3 Years
Class AAA Shares	127	634
Class A Shares	695	1,173
Class C Shares	303	860
Class I Shares	102	558

You would pay the following expenses if you did not redeem your shares of the Fund:

Expense Example, No Redemption - The Gabelli Global Financial Services Fund - USD ($)	1 Year	3 Years
Class AAA Shares	127	634
Class A Shares	695	1,173
Class C Shares	203	860
Class I Shares	102	558

<b>Portfolio Turnover </b>

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 the Fund’s shares are held in a taxable account. These costs, which are not reflected in the annual fund operating expenses or in the example, affect the Fund’s performance.

<b>Principal Investment Strategies </b>

Under normal market conditions, the Fund invests at least 80% of the value of its net assets, plus any borrowings for investment purposes, in the securities of companies principally engaged in the group of industries comprising the financial services sector. As a fundamental policy, the Fund will concentrate (invest at least 25% of the value of its net assets) in the securities of companies principally engaged in the group of industries comprising the financial services sector. The Fund may invest in the equity securities of such companies, such as common stock, or in the debt securities of such companies, such as corporate bonds or other financial instruments, in accordance with the foregoing 80% policy. The Fund may invest in companies without regard to market capitalization and may invest in issuers in foreign countries, including countries with developed or emerging markets. As a “global” fund, the Fund invests in securities of issuers, or related investments thereof, located in at least three countries, and at least 40% of the Fund’s total net assets will be invested in securities of non-U.S. issuers or related investments thereof.

The Fund considers a company to be principally engaged in the group of industries comprising the financial services sector if it devotes a significant portion of its assets to, or derives a significant portion of its revenues from, providing financial services. Such services include but are not limited to the following: commercial, consumer, and specialized banking and financing; asset management; publicly-traded, government sponsored financial enterprises; insurance; accountancy; mortgage REITs; brokerage; securities exchanges and electronic trading platforms; financial data, technology, and analysis; and financial transaction and other financial processing services.

The 1940 Act restricts the Fund from acquiring the securities of any company that derives more than 15% of its gross revenues from securities related activities, such as a broker, dealer, underwriter or a federally registered investment adviser (a “Securities Related Issuer”), subject to exception. Under Rule 12d3-1 under the 1940 Act, however, the Fund may generally purchase up to 5% of any class of equity securities of a Securities Related Issuer, or up to 10% of the outstanding principal amount of debt securities of a Securities Related Issuer, so long as, in each case, no more than 5% of the Fund’s total assets are invested in the Securities Related Issuer. These limitations are measured at the time of investment. Rule 12d3-1 may operate to limit the size of the Fund’s investment position with respect to one or more Securities Related Issuers. The 1940 Act also restricts the Fund from acquiring any security issued by an insurance company if the Fund owns, or will own as a result of the acquisition, more than 10% of the total outstanding voting stock of the insurance company. The 1940 Act may operate to limit the size of the Fund’s investment position with respect to one or more insurance companies.

The Adviser’s investment philosophy with respect to buying and selling equity securities is to identify assets that are selling in the public market at a discount to their private market value (“PMV”). The Adviser defines PMV as the value informed purchasers are willing to pay to acquire assets with similar characteristics. The Adviser considers factors such as price, earnings expectations, earnings and price histories, balance sheet characteristics, and perceived management skills. The Adviser also considers changes in economic and political outlooks as well as individual corporate developments. Further, the Adviser looks for a catalyst, something indigenous to the company, its industry or geographic positioning that may surface additional value, including, but not limited to, industry developments, regulatory changes, changes in management, sale or spin-off of a division, or the development of a profitable new business. The Adviser expects to seek to sell any Fund investments that lose their perceived value relative to other investments, which could occur because of, among other things, a security reaching a predetermined price target, a change to a company’s fundamentals that make the risk/reward profile unattractive, or a need to improve the overall risk/reward profile of the Fund.

The Fund may invest in non-U.S. equity securities through depositary receipts, including American Depositary Receipts (“ADRs”), European Depositary Receipts (“EDRs”), Global Depositary Receipts (“GDRs”) and other similar global instruments, which are generally subject to risks associated with equity securities and investments in foreign (non-U.S.) securities. ADRs are receipts issued by U.S. banks or trust companies in respect of securities of foreign issuers held on deposit for use in the U.S. securities markets. EDRs, which are sometimes referred to as Continental Depositary Receipts, are receipts issued in Europe, typically by non-U.S. banks and trust companies, that evidence ownership of either non-U.S. or domestic underlying securities. GDRs are depositary receipts structured like global debt issues to facilitate trading on an international basis. ADRs are usually denominated in U.S. dollars and dividends and other payments from the issuer are converted by the custodian into U.S. dollars before payment to receipt holders. In most other respects, ADRs, EDRs and GDRs for foreign securities have the same characteristics as the underlying securities.

<b>Principal Risks </b>

You may want to invest in the Fund if:

• you are a long term investor
• you seek capital appreciation
• you believe that the market will favor financial services companies over the long term

The Fund’s share price will fluctuate with changes in the market value of the Fund’s portfolio securities. Stocks are subject to market, economic, and business risks that may cause their prices to fluctuate. The Fund is also subject to the risk that the Adviser’s judgments about above average growth potential of a particular company is incorrect and that the perceived value of such company’s stock is not realized by the market, or that the price of the Fund’s portfolio securities will decline. Your investment in the Fund is not guaranteed; you may lose money by investing in the Fund. When you sell Fund shares, they may be worth more or less than what you paid for them.

Investing in the Fund involves the following risks:

• Equity Risk.    Equity risk is the risk that the prices of the securities held by the Fund will change due to general market and economic conditions, perceptions regarding the industries in which the companies issuing the securities participate, and the issuer company’s particular circumstances.

• Concentration Risk.    The Fund concentrates its assets (i.e., invests 25% or more of its net assets) in securities of companies in the financial services sector, and, as a result, the Fund may be subject to greater volatility with respect to its portfolio securities than a fund that is more broadly diversified. Accordingly, the Fund is subject to the risk that its performance may be hurt disproportionately by the poor performance of relatively few securities.

• Financial Services Risk.    The Fund will concentrate its investments in securities issued by financial services companies. Financial services companies can be significantly affected by changing economic conditions, demand for consumer loans, refinancing activity and intense competition, including price competition. Profitability can be largely dependent on the availability and cost of capital and the rate of consumer debt defaults, and can fluctuate significantly when interest rates change; unstable and/or rising interest rates may have a disproportionate effect on companies in the financial services sector. Financial services companies are subject to extensive government regulation, which can change frequently and may adversely affect the scope of their activities, the prices they can charge and the amount of capital they must maintain, or may affect them in other ways that are unforeseeable. In the past, financial services companies in general experienced considerable financial distress, which led to the implementation of government programs designed to ease that distress.

• Foreign Securities Risk.    Investments in foreign securities involve risks relating to political, social, and economic developments abroad, as well as risks resulting from the differences between the regulations to which U.S. and foreign issuers and markets are subject. These risks include expropriation, differing accounting and disclosure standards, currency exchange risks, settlement difficulties, market illiquidity, difficulties enforcing legal rights, and greater transaction costs. These risks are more pronounced in the securities of companies located in emerging markets.

• Emerging Market Risk.    Foreign securities risks are more pronounced in emerging markets. Investments in emerging markets may experience sharp price swings, as there may be less government supervision and regulation of business in such markets, and may entail risks relating to political and economic instability and expropriation, nationalization, confiscation or the imposition of restrictions on foreign investment, lack of hedging instruments, and restrictions on repatriation of capital invested. Securities markets in emerging markets may be less liquid and developed than those in the United States, potentially making prices erratic. Economic or political crises may detrimentally affect investments in emerging markets. Emerging market countries may experience substantial rates of inflation or deflation. The economies of developing countries tend to be dependent upon international trade. There may be little financial information available about emerging market issuers, and it may be difficult to obtain or enforce a judgment against them. Other risks include a high concentration of investors, financial intermediaries, and market capitalization and trading volume in a small number of issuers and industries; vulnerability to changes in commodity prices due to overdependence on exports, including gold and natural resources, overburdened infrastructure and obsolete or unseasoned financial systems; environmental problems; less developed legal systems; and less reliable securities custodial services and settlement practices. For all of these reasons, investments in emerging markets may be considered speculative.

• Currency Risk.    Fluctuations in exchange rates between the U.S. dollar and foreign currencies may negatively affect an investment. Adverse changes in exchange rates may erode or reverse any gains produced by foreign-currency denominated investments and may widen any losses. The Fund may, but is not required to, seek to reduce currency risk by hedging part or all of its exposure to various foreign currencies. In addition, the Fund’s investments could be adversely affected by delays in, or a refusal to grant, repatriation of funds or conversion of emerging market currencies.

• Depositary Receipts.    The Fund may invest in non-U.S. equity securities through depositary receipts, including ADRs, EDRs, GDRs and other similar global instruments. While ADRs, EDRs and GDRs may not necessarily be denominated in the same currency as the securities into which they may be converted, many of the risks associated with foreign (non-U.S.) securities may also apply to ADRs, EDRs and GDRs. In addition, the underlying issuers of certain depositary receipts, particularly unsponsored or unregistered depositary receipts, are under no obligation to distribute shareholder communications to the holders of such receipts, or to pass through to them any voting rights with respect to the deposited securities. Depositary receipts that are not sponsored by the issuer may be less liquid and there may be less readily available public information about the issuer.

• Issuer Risk.    The value of a security may decline for a number of reasons that directly relate to an issuer, such as management performance, financial leverage and reduced demand for the issuer’s goods or services, as well as the historical and prospective earnings of the issuer and the value of its assets or factors unrelated to the issuer’s value, such as investor perception.

• Management Risk.    If the portfolio manager is incorrect in his assessment of the growth prospects of the securities the Fund holds, then the value of the Fund’s shares may decline.

• Non-Diversification Risk.    As a non-diversified mutual fund, more of the Fund’s assets may be focused in the common stocks of a small number of issuers, which may make the value of the Fund’s shares more sensitive to changes in the market value of a single issuer or industry than shares of a diversified mutual fund.

• Small and Mid Capitalization Companies Risk.    Investing in securities of small and mid-capitalization companies may involve greater risks than investing in larger, more established issuers. Small and mid-capitalization companies may be less well established and may have a more highly leveraged capital structure, less liquidity, a smaller investor base, limited product lines, greater dependence on a few customers, or a few key personnel and similar factors that can make their business and stock market performance susceptible to greater fluctuation and volatility.

• Large Capitalization Companies Risk.    Companies with $10 billion or more in market capitalization are considered by the Adviser to be large-capitalization companies. Large-capitalization companies generally experience slower rates of growth in earnings per share than do mid- and small-capitalization companies.

• New Fund Risk.    The Fund is new with a limited operating history and may have higher expenses. There can be no assurance that the Fund will grow to or maintain an economically viable size. The Fund could cease operations, and investors may be required to liquidate or transfer their assets at a loss. However, the expense limitation in place limits this risk through the end of its term.

• Value Investing Risk.    The Fund invests in “value” stocks. The portfolio manager may be wrong in the assessment of a company’s value and the stocks the Fund holds may not reach what the portfolio manager believes are their full values. From time to time “value” investing falls out of favor with investors. During those periods, the Fund’s relative performance may suffer.

Fixed Income Securities Risks.    Because the Fund may invest in fixed income securities, it is subject to the following risks:

• Interest Rate Risk.    When interest rates decline, the value of fixed income securities generally rises; and when interest rates rise, the value of such securities generally declines.

• Issuer Risk.    Issuer risk is the risk that the value of a fixed income security may decline for a number of reasons which directly relate to the issuer.

• Credit Risk.    Credit risk is the risk that one or more fixed income securities in the Fund’s portfolio will decline in price or fail to pay interest/distributions or principal when due because the issuer of the security experiences a decline in its financial status.

• Prepayment Risk.    Prepayment risk is the risk that during periods of declining interest rates, borrowers may exercise their option to prepay principal earlier than scheduled, which could force the Fund to reinvest in lower yielding securities.

• Reinvestment Risk.    Reinvestment risk is the risk that income from the Fund’s portfolio will decline if the Fund invests the proceeds from matured, traded or called fixed income securities at market interest rates that are below the Fund portfolio’s current earnings rate.

• Duration and Maturity Risk.    In comparison to maturity (which is the date on which the issuer of a debt instrument is obligated to repay the principal amount), duration is a measure of the price volatility of a debt instrument as a result in changes in market rates of interest, based on the weighted average timing of the instrument’s expected principal and interest payments. In general, a portfolio of securities with a longer duration can be expected to be more sensitive to interest rate changes than a portfolio with a shorter duration.

Corporate Bonds Risk.    The market value of a corporate bond generally may be expected to rise and fall inversely with interest rates. The market value of intermediate and longer term corporate bonds is generally more sensitive to changes in interest rates than is the market value of shorter term corporate bonds.

Non-Investment Grade Securities Risk.    The prices of lower grade securities are more sensitive to negative developments, such as a decline in the issuer’s revenues or a general economic downturn, than are the prices of higher grade securities. Securities of below investment grade quality are predominantly speculative with respect to the issuer’s capacity to pay interest and repay principal when due and therefore involve a greater risk of default.

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance corporation or any other government agency.

<b>Performance </b>

As of the date of this Prospectus, the Fund was newly organized and had no operations. Accordingly, no performance information has been presented for the Fund. When available, performance information for the Fund will be at www.gabelli.com.

[1] “Other Expenses” are based on estimated amounts for the current fiscal year. The Adviser has contractually agreed to waive its investment advisory fees and/or to reimburse expenses of the Fund to the extent necessary to maintain the Total Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement (excluding brokerage costs, acquired fund fees and expenses, interest, taxes, and extraordinary expenses) at no more than an annual rate of 1.25%, 1.25%, 2.00%, and 1.00% for Class AAA, Class A, Class C, and Class I shares, respectively. Under this same arrangement, the Fund has also agreed, during the two year period following the year of any such waiver or reimbursement by the Adviser, to repay such amount, but only to the extent the Fund’s adjusted Total Annual Fund Operating Expenses would not exceed an annual rate of 1.25%, 1.25%, 2.00%, and 1.00% for Class AAA, Class A, Class C, and Class I shares, respectively, after giving effect to the repayments. This arrangement is in effect through January 31, 2020, and may be terminated only by the Board of Directors of the Company before such time. The Fund will carry forward any fees and expenses in excess of the expense limitation and repay the Adviser such amount provided the Fund is able to do so without exceeding the lesser of (1) the expense limit in effect at the time of the waiver or reimbursement, as applicable, or (2) the expense limit in effect at the time of recoupment after giving effect to the repayment.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	GABELLI EQUITY SERIES FUNDS INC
Prospectus Date	rr_ProspectusDate	Oct. 01, 2018
The Gabelli Global Financial Services Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<b>THE GABELLI GLOBAL FINANCIAL SERVICES FUND (the “Fund”) </b>
Objective [Heading]	rr_ObjectiveHeading	<b>Investment Objective </b>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund seeks to provide capital appreciation.
Expense [Heading]	rr_ExpenseHeading	<b>Fees and Expenses of the Fund: </b>
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold the following classes of shares of the Fund. You may qualify for sales charge discounts on Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 in Class A shares of the Gabelli family of mutual funds. More information about these and other discounts is available from your financial professional and in the section entitled, “Classes of Shares” on page 18 of the prospectus and in Appendix A, “Sales Charge Reductions and Waivers Available through Certain Intermediaries,” attached to the Fund’s prospectus.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	<b>Shareholder Fees</b> <br/>(fees paid directly from your investment):
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<b>Annual Fund Operating Expenses</b><br/> (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, 2020
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<b>Portfolio Turnover </b>
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 the Fund’s shares are held in a taxable account. These costs, which are not reflected in the annual fund operating expenses or in the example, affect the Fund’s performance.
Expense Breakpoint Discounts [Text]	rr_ExpenseBreakpointDiscounts	You may qualify for sales charge discounts on Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 in Class A shares of the Gabelli family of mutual funds. More information about these and other discounts is available from your financial professional and in the section entitled, “Classes of Shares” on page 18 of the prospectus and in Appendix A, “Sales Charge Reductions and Waivers Available through Certain Intermediaries,” attached to the Fund’s prospectus.
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	$ 50,000
Other Expenses, New Fund, Based on Estimates [Text]	rr_OtherExpensesNewFundBasedOnEstimates	"Other Expenses" are based on estimated amounts for the current fiscal year.
Expense Example [Heading]	rr_ExpenseExampleHeading	<b>Expense Example</b>
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 invest $10,000 in the Fund for the time periods shown and then redeem all of your shares at the end of those periods. The example assumes a waiver of expenses through the date of the expiration of the waiver, and reflects Total Annual Fund Operating Expenses following the date of the expiration of the waiver. The example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Expense Example, No Redemption, By Year, Caption [Text]	rr_ExpenseExampleNoRedemptionByYearCaption	You would pay the following expenses if you did not redeem your shares of the Fund:
Strategy [Heading]	rr_StrategyHeading	<b>Principal Investment Strategies </b>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	Under normal market conditions, the Fund invests at least 80% of the value of its net assets, plus any borrowings for investment purposes, in the securities of companies principally engaged in the group of industries comprising the financial services sector. As a fundamental policy, the Fund will concentrate (invest at least 25% of the value of its net assets) in the securities of companies principally engaged in the group of industries comprising the financial services sector. The Fund may invest in the equity securities of such companies, such as common stock, or in the debt securities of such companies, such as corporate bonds or other financial instruments, in accordance with the foregoing 80% policy. The Fund may invest in companies without regard to market capitalization and may invest in issuers in foreign countries, including countries with developed or emerging markets. As a “global” fund, the Fund invests in securities of issuers, or related investments thereof, located in at least three countries, and at least 40% of the Fund’s total net assets will be invested in securities of non-U.S. issuers or related investments thereof. The Fund considers a company to be principally engaged in the group of industries comprising the financial services sector if it devotes a significant portion of its assets to, or derives a significant portion of its revenues from, providing financial services. Such services include but are not limited to the following: commercial, consumer, and specialized banking and financing; asset management; publicly-traded, government sponsored financial enterprises; insurance; accountancy; mortgage REITs; brokerage; securities exchanges and electronic trading platforms; financial data, technology, and analysis; and financial transaction and other financial processing services. The 1940 Act restricts the Fund from acquiring the securities of any company that derives more than 15% of its gross revenues from securities related activities, such as a broker, dealer, underwriter or a federally registered investment adviser (a “Securities Related Issuer”), subject to exception. Under Rule 12d3-1 under the 1940 Act, however, the Fund may generally purchase up to 5% of any class of equity securities of a Securities Related Issuer, or up to 10% of the outstanding principal amount of debt securities of a Securities Related Issuer, so long as, in each case, no more than 5% of the Fund’s total assets are invested in the Securities Related Issuer. These limitations are measured at the time of investment. Rule 12d3-1 may operate to limit the size of the Fund’s investment position with respect to one or more Securities Related Issuers. The 1940 Act also restricts the Fund from acquiring any security issued by an insurance company if the Fund owns, or will own as a result of the acquisition, more than 10% of the total outstanding voting stock of the insurance company. The 1940 Act may operate to limit the size of the Fund’s investment position with respect to one or more insurance companies. The Adviser’s investment philosophy with respect to buying and selling equity securities is to identify assets that are selling in the public market at a discount to their private market value (“PMV”). The Adviser defines PMV as the value informed purchasers are willing to pay to acquire assets with similar characteristics. The Adviser considers factors such as price, earnings expectations, earnings and price histories, balance sheet characteristics, and perceived management skills. The Adviser also considers changes in economic and political outlooks as well as individual corporate developments. Further, the Adviser looks for a catalyst, something indigenous to the company, its industry or geographic positioning that may surface additional value, including, but not limited to, industry developments, regulatory changes, changes in management, sale or spin-off of a division, or the development of a profitable new business. The Adviser expects to seek to sell any Fund investments that lose their perceived value relative to other investments, which could occur because of, among other things, a security reaching a predetermined price target, a change to a company’s fundamentals that make the risk/reward profile unattractive, or a need to improve the overall risk/reward profile of the Fund. The Fund may invest in non-U.S. equity securities through depositary receipts, including American Depositary Receipts (“ADRs”), European Depositary Receipts (“EDRs”), Global Depositary Receipts (“GDRs”) and other similar global instruments, which are generally subject to risks associated with equity securities and investments in foreign (non-U.S.) securities. ADRs are receipts issued by U.S. banks or trust companies in respect of securities of foreign issuers held on deposit for use in the U.S. securities markets. EDRs, which are sometimes referred to as Continental Depositary Receipts, are receipts issued in Europe, typically by non-U.S. banks and trust companies, that evidence ownership of either non-U.S. or domestic underlying securities. GDRs are depositary receipts structured like global debt issues to facilitate trading on an international basis. ADRs are usually denominated in U.S. dollars and dividends and other payments from the issuer are converted by the custodian into U.S. dollars before payment to receipt holders. In most other respects, ADRs, EDRs and GDRs for foreign securities have the same characteristics as the underlying securities.
Risk [Heading]	rr_RiskHeading	<b>Principal Risks </b>
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	You may want to invest in the Fund if: you are a long term investor you seek capital appreciation you believe that the market will favor financial services companies over the long term The Fund’s share price will fluctuate with changes in the market value of the Fund’s portfolio securities. Stocks are subject to market, economic, and business risks that may cause their prices to fluctuate. The Fund is also subject to the risk that the Adviser’s judgments about above average growth potential of a particular company is incorrect and that the perceived value of such company’s stock is not realized by the market, or that the price of the Fund’s portfolio securities will decline. Your investment in the Fund is not guaranteed; you may lose money by investing in the Fund. When you sell Fund shares, they may be worth more or less than what you paid for them. Investing in the Fund involves the following risks: Equity Risk.    Equity risk is the risk that the prices of the securities held by the Fund will change due to general market and economic conditions, perceptions regarding the industries in which the companies issuing the securities participate, and the issuer company’s particular circumstances. Concentration Risk.    The Fund concentrates its assets (i.e., invests 25% or more of its net assets) in securities of companies in the financial services sector, and, as a result, the Fund may be subject to greater volatility with respect to its portfolio securities than a fund that is more broadly diversified. Accordingly, the Fund is subject to the risk that its performance may be hurt disproportionately by the poor performance of relatively few securities. Financial Services Risk.    The Fund will concentrate its investments in securities issued by financial services companies. Financial services companies can be significantly affected by changing economic conditions, demand for consumer loans, refinancing activity and intense competition, including price competition. Profitability can be largely dependent on the availability and cost of capital and the rate of consumer debt defaults, and can fluctuate significantly when interest rates change; unstable and/or rising interest rates may have a disproportionate effect on companies in the financial services sector. Financial services companies are subject to extensive government regulation, which can change frequently and may adversely affect the scope of their activities, the prices they can charge and the amount of capital they must maintain, or may affect them in other ways that are unforeseeable. In the past, financial services companies in general experienced considerable financial distress, which led to the implementation of government programs designed to ease that distress. Foreign Securities Risk.    Investments in foreign securities involve risks relating to political, social, and economic developments abroad, as well as risks resulting from the differences between the regulations to which U.S. and foreign issuers and markets are subject. These risks include expropriation, differing accounting and disclosure standards, currency exchange risks, settlement difficulties, market illiquidity, difficulties enforcing legal rights, and greater transaction costs. These risks are more pronounced in the securities of companies located in emerging markets. Emerging Market Risk.    Foreign securities risks are more pronounced in emerging markets. Investments in emerging markets may experience sharp price swings, as there may be less government supervision and regulation of business in such markets, and may entail risks relating to political and economic instability and expropriation, nationalization, confiscation or the imposition of restrictions on foreign investment, lack of hedging instruments, and restrictions on repatriation of capital invested. Securities markets in emerging markets may be less liquid and developed than those in the United States, potentially making prices erratic. Economic or political crises may detrimentally affect investments in emerging markets. Emerging market countries may experience substantial rates of inflation or deflation. The economies of developing countries tend to be dependent upon international trade. There may be little financial information available about emerging market issuers, and it may be difficult to obtain or enforce a judgment against them. Other risks include a high concentration of investors, financial intermediaries, and market capitalization and trading volume in a small number of issuers and industries; vulnerability to changes in commodity prices due to overdependence on exports, including gold and natural resources, overburdened infrastructure and obsolete or unseasoned financial systems; environmental problems; less developed legal systems; and less reliable securities custodial services and settlement practices. For all of these reasons, investments in emerging markets may be considered speculative. Currency Risk.    Fluctuations in exchange rates between the U.S. dollar and foreign currencies may negatively affect an investment. Adverse changes in exchange rates may erode or reverse any gains produced by foreign-currency denominated investments and may widen any losses. The Fund may, but is not required to, seek to reduce currency risk by hedging part or all of its exposure to various foreign currencies. In addition, the Fund’s investments could be adversely affected by delays in, or a refusal to grant, repatriation of funds or conversion of emerging market currencies. Depositary Receipts.    The Fund may invest in non-U.S. equity securities through depositary receipts, including ADRs, EDRs, GDRs and other similar global instruments. While ADRs, EDRs and GDRs may not necessarily be denominated in the same currency as the securities into which they may be converted, many of the risks associated with foreign (non-U.S.) securities may also apply to ADRs, EDRs and GDRs. In addition, the underlying issuers of certain depositary receipts, particularly unsponsored or unregistered depositary receipts, are under no obligation to distribute shareholder communications to the holders of such receipts, or to pass through to them any voting rights with respect to the deposited securities. Depositary receipts that are not sponsored by the issuer may be less liquid and there may be less readily available public information about the issuer. Issuer Risk.    The value of a security may decline for a number of reasons that directly relate to an issuer, such as management performance, financial leverage and reduced demand for the issuer’s goods or services, as well as the historical and prospective earnings of the issuer and the value of its assets or factors unrelated to the issuer’s value, such as investor perception. Management Risk.    If the portfolio manager is incorrect in his assessment of the growth prospects of the securities the Fund holds, then the value of the Fund’s shares may decline. Non-Diversification Risk.    As a non-diversified mutual fund, more of the Fund’s assets may be focused in the common stocks of a small number of issuers, which may make the value of the Fund’s shares more sensitive to changes in the market value of a single issuer or industry than shares of a diversified mutual fund. Small and Mid Capitalization Companies Risk.    Investing in securities of small and mid-capitalization companies may involve greater risks than investing in larger, more established issuers. Small and mid-capitalization companies may be less well established and may have a more highly leveraged capital structure, less liquidity, a smaller investor base, limited product lines, greater dependence on a few customers, or a few key personnel and similar factors that can make their business and stock market performance susceptible to greater fluctuation and volatility. Large Capitalization Companies Risk.    Companies with $10 billion or more in market capitalization are considered by the Adviser to be large-capitalization companies. Large-capitalization companies generally experience slower rates of growth in earnings per share than do mid- and small-capitalization companies. New Fund Risk.    The Fund is new with a limited operating history and may have higher expenses. There can be no assurance that the Fund will grow to or maintain an economically viable size. The Fund could cease operations, and investors may be required to liquidate or transfer their assets at a loss. However, the expense limitation in place limits this risk through the end of its term. Value Investing Risk.    The Fund invests in “value” stocks. The portfolio manager may be wrong in the assessment of a company’s value and the stocks the Fund holds may not reach what the portfolio manager believes are their full values. From time to time “value” investing falls out of favor with investors. During those periods, the Fund’s relative performance may suffer. Fixed Income Securities Risks.    Because the Fund may invest in fixed income securities, it is subject to the following risks: Interest Rate Risk.    When interest rates decline, the value of fixed income securities generally rises; and when interest rates rise, the value of such securities generally declines. Issuer Risk.    Issuer risk is the risk that the value of a fixed income security may decline for a number of reasons which directly relate to the issuer. Credit Risk.    Credit risk is the risk that one or more fixed income securities in the Fund’s portfolio will decline in price or fail to pay interest/distributions or principal when due because the issuer of the security experiences a decline in its financial status. Prepayment Risk.    Prepayment risk is the risk that during periods of declining interest rates, borrowers may exercise their option to prepay principal earlier than scheduled, which could force the Fund to reinvest in lower yielding securities. Reinvestment Risk.    Reinvestment risk is the risk that income from the Fund’s portfolio will decline if the Fund invests the proceeds from matured, traded or called fixed income securities at market interest rates that are below the Fund portfolio’s current earnings rate. Duration and Maturity Risk.    In comparison to maturity (which is the date on which the issuer of a debt instrument is obligated to repay the principal amount), duration is a measure of the price volatility of a debt instrument as a result in changes in market rates of interest, based on the weighted average timing of the instrument’s expected principal and interest payments. In general, a portfolio of securities with a longer duration can be expected to be more sensitive to interest rate changes than a portfolio with a shorter duration. Corporate Bonds Risk.    The market value of a corporate bond generally may be expected to rise and fall inversely with interest rates. The market value of intermediate and longer term corporate bonds is generally more sensitive to changes in interest rates than is the market value of shorter term corporate bonds. Non-Investment Grade Securities Risk.    The prices of lower grade securities are more sensitive to negative developments, such as a decline in the issuer’s revenues or a general economic downturn, than are the prices of higher grade securities. Securities of below investment grade quality are predominantly speculative with respect to the issuer’s capacity to pay interest and repay principal when due and therefore involve a greater risk of default. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance corporation or any other government agency.
Risk Lose Money [Text]	rr_RiskLoseMoney	Your investment in the Fund is not guaranteed; you may lose money by investing in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	<ul type="square"><li> <b>Non-Diversification Risk.</b>    As a non-diversified mutual fund, more of the Fund’s assets may be focused in the common stocks of a small number of issuers, which may make the value of the Fund’s shares more sensitive to changes in the market value of a single issuer or industry than shares of a diversified mutual fund. </li></ul>
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<b>Performance </b>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	As of the date of this Prospectus, the Fund was newly organized and had no operations. Accordingly, no performance information has been presented for the Fund. When available, performance information for the Fund will be at www.gabelli.com.
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	As of the date of this Prospectus, the Fund was newly organized and had no operations. Accordingly, no performance information has been presented for the Fund.
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.gabelli.com
The Gabelli Global Financial Services Fund | Class AAA Shares
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of redemption or offering price, whichever is lower)	rr_MaximumDeferredSalesChargeOverOther	none
Maximum Sales Charge (Load) Imposed on Reinvested Dividends (as a percentage of amount invested)	rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther	none
Redemption Fees (as a percentage of amount redeemed for shares held 7 days or less)	rr_RedemptionFeeOverRedemption	2.00%
Exchange Fee	rr_ExchangeFeeOverRedemption	none
Management Fees	rr_ManagementFeesOverAssets	1.00%
Distribution and Service (Rule 12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses	rr_OtherExpensesOverAssets	1.13%	[1]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	2.38%	[1]
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(1.13%)	[1]
Total Annual Fund Operating Expenses After Fee Wavier and/or Expense Reimbursement	rr_NetExpensesOverAssets	1.25%
1 Year	rr_ExpenseExampleYear01	$ 127
3 Years	rr_ExpenseExampleYear03	634
1 Year	rr_ExpenseExampleNoRedemptionYear01	127
3 Years	rr_ExpenseExampleNoRedemptionYear03	$ 634
The Gabelli Global Financial Services Fund | Class A Shares
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	5.75%
Maximum Deferred Sales Charge (Load) (as a percentage of redemption or offering price, whichever is lower)	rr_MaximumDeferredSalesChargeOverOther	none
Maximum Sales Charge (Load) Imposed on Reinvested Dividends (as a percentage of amount invested)	rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther	none
Redemption Fees (as a percentage of amount redeemed for shares held 7 days or less)	rr_RedemptionFeeOverRedemption	2.00%
Exchange Fee	rr_ExchangeFeeOverRedemption	none
Management Fees	rr_ManagementFeesOverAssets	1.00%
Distribution and Service (Rule 12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses	rr_OtherExpensesOverAssets	1.13%	[1]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	2.38%	[1]
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(1.13%)	[1]
Total Annual Fund Operating Expenses After Fee Wavier and/or Expense Reimbursement	rr_NetExpensesOverAssets	1.25%
1 Year	rr_ExpenseExampleYear01	$ 695
3 Years	rr_ExpenseExampleYear03	1,173
1 Year	rr_ExpenseExampleNoRedemptionYear01	695
3 Years	rr_ExpenseExampleNoRedemptionYear03	$ 1,173
The Gabelli Global Financial Services Fund | Class C Shares
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of redemption or offering price, whichever is lower)	rr_MaximumDeferredSalesChargeOverOther	1.00%
Maximum Sales Charge (Load) Imposed on Reinvested Dividends (as a percentage of amount invested)	rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther	none
Redemption Fees (as a percentage of amount redeemed for shares held 7 days or less)	rr_RedemptionFeeOverRedemption	2.00%
Exchange Fee	rr_ExchangeFeeOverRedemption	none
Management Fees	rr_ManagementFeesOverAssets	1.00%
Distribution and Service (Rule 12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other Expenses	rr_OtherExpensesOverAssets	1.13%	[1]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	3.13%	[1]
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(1.13%)	[1]
Total Annual Fund Operating Expenses After Fee Wavier and/or Expense Reimbursement	rr_NetExpensesOverAssets	2.00%
1 Year	rr_ExpenseExampleYear01	$ 303
3 Years	rr_ExpenseExampleYear03	860
1 Year	rr_ExpenseExampleNoRedemptionYear01	203
3 Years	rr_ExpenseExampleNoRedemptionYear03	$ 860
The Gabelli Global Financial Services Fund | Class I Shares
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of redemption or offering price, whichever is lower)	rr_MaximumDeferredSalesChargeOverOther	none
Maximum Sales Charge (Load) Imposed on Reinvested Dividends (as a percentage of amount invested)	rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther	none
Redemption Fees (as a percentage of amount redeemed for shares held 7 days or less)	rr_RedemptionFeeOverRedemption	2.00%
Exchange Fee	rr_ExchangeFeeOverRedemption	none
Management Fees	rr_ManagementFeesOverAssets	1.00%
Distribution and Service (Rule 12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	1.13%	[1]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	2.13%	[1]
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(1.13%)	[1]
Total Annual Fund Operating Expenses After Fee Wavier and/or Expense Reimbursement	rr_NetExpensesOverAssets	1.00%
1 Year	rr_ExpenseExampleYear01	$ 102
3 Years	rr_ExpenseExampleYear03	558
1 Year	rr_ExpenseExampleNoRedemptionYear01	102
3 Years	rr_ExpenseExampleNoRedemptionYear03	$ 558

[1] “Other Expenses” are based on estimated amounts for the current fiscal year. The Adviser has contractually agreed to waive its investment advisory fees and/or to reimburse expenses of the Fund to the extent necessary to maintain the Total Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement (excluding brokerage costs, acquired fund fees and expenses, interest, taxes, and extraordinary expenses) at no more than an annual rate of 1.25%, 1.25%, 2.00%, and 1.00% for Class AAA, Class A, Class C, and Class I shares, respectively. Under this same arrangement, the Fund has also agreed, during the two year period following the year of any such waiver or reimbursement by the Adviser, to repay such amount, but only to the extent the Fund’s adjusted Total Annual Fund Operating Expenses would not exceed an annual rate of 1.25%, 1.25%, 2.00%, and 1.00% for Class AAA, Class A, Class C, and Class I shares, respectively, after giving effect to the repayments. This arrangement is in effect through January 31, 2020, and may be terminated only by the Board of Directors of the Company before such time. The Fund will carry forward any fees and expenses in excess of the expense limitation and repay the Adviser such amount provided the Fund is able to do so without exceeding the lesser of (1) the expense limit in effect at the time of the waiver or reimbursement, as applicable, or (2) the expense limit in effect at the time of recoupment after giving effect to the repayment.

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Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	GABELLI EQUITY SERIES FUNDS INC
Prospectus Date	rr_ProspectusDate	Oct. 01, 2018
Document Creation Date	dei_DocumentCreationDate	Oct. 01, 2018