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 indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year, that the operating expenses remain the same and that any expense reimbursement arrangement remains in place for the contractual period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy Narrative

rr_StrategyNarrativeTextBlock

Under normal circumstances, the Fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in securities issued, backed or otherwise guaranteed by the U.S. Government, or its agencies or instrumentalities (the “80% Policy”). The Fund may invest in mortgage-backed securities (“MBS”), including collateralized mortgage obligations, issued, backed or otherwise guaranteed by the U.S. Government or its agencies or instrumentalities or privately issued but collateralized by fixed or adjustable rate mortgages that are insured, guaranteed or otherwise backed by the U.S. Government, or its agencies or instrumentalities. These investments may include MBS that have had a history of refinancing opportunities (so-called “seasoned MBS”). The Fund may invest significantly in securities issued by various U.S. Government-sponsored entities, such as the Federal Home Loan Mortgage Corporation and the Federal National Mortgage Association. While such issuers may be chartered or sponsored by acts of Congress, their securities are neither issued nor guaranteed by the U.S. Department of the Treasury. The Fund’s shares are not guaranteed by the U.S. Government.

The Fund may invest up to 20% of its net assets in instruments other than securities issued, backed or otherwise guaranteed by the U.S. Government, or its agencies or instrumentalities including privately issued residential and commercial MBS, mortgage-related loans, asset-backed securities, non-U.S. mortgage-related instruments and other income instruments. The Fund may invest in instruments of any credit rating, including those rated below investment grade (rated below BBB by either S&P Global Ratings or Fitch Ratings, or below Baa by Moody’s Investors Service, Inc.) or in unrated instruments considered to be of comparable quality by the investment adviser (often referred to as “junk” instruments).

The Fund may invest in stripped securities which may be issued by the U.S. Government, its agencies or instrumentalities, and may also be issued by private originators or investors, including depository institutions, banks, investment banks and special purpose subsidiaries of these entities.

The Fund may engage in derivative transactions. Transactions in derivative instruments may include: the purchase or sale of futures contracts on securities, indices or other financial instruments or currencies; options on futures contracts; exchange-traded and over-the-counter options on securities, indices, currencies and other instruments; and interest rate, credit default, inflation and total return swaps. The Fund may take short or long positions with regard to certain synthetic total return swap indices. The Fund may use interest rate swaps and options on interest rate swaps for risk management purposes and not as a speculative investment and would typically use interest rate swaps to shorten the average interest rate reset time of its holdings. The Fund may engage in other derivatives to seek return, to hedge against fluctuations in securities prices, interest rates or currency exchange rates, to change the duration of obligations held by the Fund, to manage certain investment risks and/or as a substitute for the purchase or sale of securities or currencies. Except as required by applicable regulation, there is no stated limit on the Fund’s use of derivatives for such purposes.

The portfolio managers may also use other active management techniques, such as mortgage dollar roll transactions, forward commitments, repurchase agreements, reverse repurchase agreements and any combination thereof. The Fund may enter into forward commitments to buy or sell agency MBS (to-be-announced transactions, or “TBAs”). The Fund may engage in short sales of securities with respect to not more than 25% of its net assets. The Fund may borrow from banks for investment purposes.

The portfolio managers seek to purchase securities believed to be the best relative value with regard to price, yield, and expected total return in relation to other available instruments. Investment decisions are primarily made on the basis of fundamental research and relative value. The portfolio managers may sell a security when they believe the security no longer represents the best relative value and the fundamental research or cash needs dictate. The portfolio managers may also consider financially material environmental, social and governance factors in evaluating an issuer. These considerations may be taken into account alongside other factors in the investment selection process.

Risk

rr_RiskHeading

Principal Risks

Risk Lose Money

rr_RiskLoseMoney

The Fund is not a complete investment program and there is no guarantee that the Fund will achieve its investment objective. It is possible to lose money by investing in the Fund.

Bar Chart and Performance Table

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Performance

Performance Information Illustrates Variability of Returns

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and how the Fund’s average annual returns over time compare with those of a broad-based securities market index.

Performance Past Does Not Indicate Future

rr_PerformancePastDoesNotIndicateFuture

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

Annual Return Caption

rr_AnnualReturnCaption

Calendar year-by-year total return

Performance Table Does Reflect Sales Loads

rr_PerformanceTableDoesReflectSalesLoads

These returns reflect the maximum current sales charge for Class A (3.25%) and any applicable contingent deferred sales charge (“CDSC”) for Class C.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

After-tax returns are not relevant to shareholders who hold shares in tax-deferred accounts or to shares held by non-taxable entities.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Return After Taxes on Distributions for a period may be the same as Return Before Taxes for that period because no taxable distributions were made during that period. Also, Return After Taxes on Distributions and Sale of Fund Shares for a period may be greater than or equal to Return After Taxes on Distributions for the same period because of losses realized on the sale of Fund shares.

Average Annual Return, Caption

rr_AverageAnnualReturnCaption

Average Annual Total Return as of December 31, 2022

Prospectus [Line Items]

rr_ProspectusLineItems

One Year

rr_AverageAnnualReturnYear01

(3.65%)

Ten Years

rr_AverageAnnualReturnYear10

0.67%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

^[1]

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.10%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.05%

1 Year

rr_ExpenseExampleYear01

$ 429

5 Years

rr_ExpenseExampleYear05

907

1 Year

rr_ExpenseExampleNoRedemptionYear01

429

5 Years

rr_ExpenseExampleNoRedemptionYear05

907

2013

rr_AnnualReturn2013

(1.53%)

2015

rr_AnnualReturn2015

0.28%

2017

rr_AnnualReturn2017

1.29%

2019

rr_AnnualReturn2019

2.43%

2021

rr_AnnualReturn2021

(1.20%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest quarterly total return

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

1.91%

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2022

One Year

rr_AverageAnnualReturnYear01

(9.58%)

Ten Years

rr_AverageAnnualReturnYear10

(0.06%)

Prospectus [Line Items]

rr_ProspectusLineItems

Five Years

rr_AverageAnnualReturnYear05

(1.79%)

One Year

rr_AverageAnnualReturnYear01

(5.66%)

Ten Years

rr_AverageAnnualReturnYear10

(0.74%)

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

1.00%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.85%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.80%

3 Years

rr_ExpenseExampleYear03

577

10 Years

rr_ExpenseExampleYear10

1,969

3 Years

rr_ExpenseExampleNoRedemptionYear03

577

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,969

Five Years

rr_AverageAnnualReturnYear05

(0.83%)

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.65%

Other Expenses

rr_OtherExpensesOverAssets

0.20%

Expense Reimbursement (2)

rr_FeeWaiverOrReimbursementOverAssets

(0.05%)

^[2]

1 Year

rr_ExpenseExampleYear01

$ 82

5 Years

rr_ExpenseExampleYear05

466

1 Year

rr_ExpenseExampleNoRedemptionYear01

82

5 Years

rr_ExpenseExampleNoRedemptionYear05

466

One Year

rr_AverageAnnualReturnYear01

(6.18%)

Ten Years

rr_AverageAnnualReturnYear10

0.52%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.50%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.35%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.30%

3 Years

rr_ExpenseExampleYear03

423

10 Years

rr_ExpenseExampleYear10

1,620

3 Years

rr_ExpenseExampleNoRedemptionYear03

423

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,620

Five Years

rr_AverageAnnualReturnYear05

(0.30%)

Risk/Return

rr_RiskReturnHeading

Eaton Vance Short Duration Government Income Fund

Objective, Primary

rr_ObjectivePrimaryTextBlock

The Fund's investment objective is to seek total return.

Expense Narrative

rr_ExpenseNarrativeTextBlock

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. Investors may also pay commissions or other fees to their financial intermediary, which are not reflected below. You may qualify for a reduced sales charge on purchases of Class A shares if you invest, or agree to invest over a 13-month period, at least $100,000 in Eaton Vance funds. Certain financial intermediaries also may offer variations in Fund sales charges to their customers as described in Appendix A – Financial Intermediary Sales Charge Variations in this Prospectus. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 37 of this Prospectus and page 22 of the Fund’s Statement of Additional Information.

Operating Expenses Caption

rr_OperatingExpensesCaption

Annual Fund Operating Expenses (expenses you pay each year as a percentage of the value of your investment)

Portfolio Turnover

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” the 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 798% of the average value of its portfolio (212% excluding to-be-announced (TBA) transactions).

Expense Breakpoint Discounts

rr_ExpenseBreakpointDiscounts

You may qualify for a reduced sales charge on purchases of Class A shares if you invest, or agree to invest over a 13-month period, at least $100,000 in Eaton Vance funds. Certain financial intermediaries also may offer variations in Fund sales charges to their customers as described in Appendix A – Financial Intermediary Sales Charge Variations in this Prospectus. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 37 of this Prospectus and page 22 of the Fund’s Statement of Additional Information.

Expense Example

rr_ExpenseExampleHeading

Example.

Strategy

rr_StrategyHeading

Principal Investment Strategies

Strategy Portfolio Concentration

rr_StrategyPortfolioConcentration

Under normal circumstances, the Fund invests at least 90% of its net assets (plus any borrowings for investment purposes) in any securities issued, backed or otherwise guaranteed by the U.S. Government or its agencies or instrumentalities (the “90% Policy”). These securities include, but are not limited to, fixed or floating-rate mortgage-backed securities (“MBS”) including collateralized mortgage obligations, issued, backed or otherwise guaranteed by the U.S. Government or its agencies or instrumentalities, Treasuries and agency bonds. The Fund may invest up to 10% of its net assets in other income securities, including, but not limited to, non-agency MBS and asset-backed securities, corporate bonds, loans and money market securities. The Fund many invest in securities in any ratings category, including securities rated below investment grade or in unrated securities considered to be of comparable quality by the investment adviser (commonly referred to as “junk bonds”). The Fund’s dollar-weighted average duration will not exceed three years. The Fund is not a money market fund and does not seek to maintain a stable net asset value per share.

Risk Narrative

rr_RiskNarrativeTextBlock

Market Risk. The value of investments held by the Fund may increase or decrease in response to social, economic, political, financial, public health crises or other disruptive events (whether real, expected or perceived) in the U.S. and global markets and include events such as war, natural disasters, epidemics and pandemics, terrorism, conflicts and social unrest. These events may negatively impact broad segments of businesses and populations and may exacerbate pre-existing risks to the Fund. The frequency and magnitude of resulting changes in the value of the Fund’s investments cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in reaction to changing market conditions. Monetary and/or fiscal actions taken by U.S. or foreign governments to stimulate or stabilize the global economy may not be effective and could lead to high market volatility. No active trading market may exist for certain investments held by the Fund, which may impair the ability of the Fund to sell or to realize the full value of such investments in the event of the need to liquidate such assets.

U.S. Government Securities Risk. Although certain U.S. Government-sponsored agencies (such as the Federal Home Loan Mortgage Corporation and the Federal National Mortgage Association) may be chartered or sponsored by acts of Congress, their securities are neither issued nor guaranteed by the U.S. Treasury. U.S. Treasury securities generally have a lower return than other obligations because of their higher credit quality and market liquidity.

Mortgage- and Asset-Backed Securities Risk. Mortgage- and asset-backed securities represent interests in “pools” of commercial or residential mortgages or other assets, including consumer loans or receivables. Movements in interest rates (both increases and decreases) may quickly and significantly reduce the value of certain types of mortgage- and

asset-backed securities. Although certain mortgage- and asset-backed securities are guaranteed as to timely payment of interest and principal by a government entity, the market price for such securities is not guaranteed and will fluctuate. The purchase of mortgage- and asset-backed securities issued by non-government entities may entail greater risk than such securities that are issued or guaranteed by a government entity. Mortgage- and asset-backed securities issued by non-government entities may offer higher yields than those issued by government entities, but may also be subject to greater volatility than government issues and can also be subject to greater credit risk and the risk of default on the underlying mortgages or other assets. Investments in mortgage- and asset-backed securities are subject to both extension risk, where borrowers pay off their debt obligations more slowly in times of rising interest rates, and prepayment risk, where borrowers pay off their debt obligations sooner than expected in times of declining interest rates.

Stripped Securities Risk. Stripped Securities (“Strips”) are usually structured with classes that receive different proportions of the interest and principal distributions from an underlying asset or pool of underlying assets. Classes may receive only interest distributions (interest-only “IO”) or only principal (principal-only “PO”). Strips are particularly sensitive to changes in interest rates as such changes may increase or decrease prepayments of principal. A rapid or unexpected increase in prepayments can significantly depress the value of IO Strips, while a rapid or unexpected decrease can have the same effect on PO Strips.

Credit Risk. Investments in fixed income and other debt obligations (referred to below as “debt instruments”) are subject to the risk of non-payment of scheduled principal and interest. Changes in economic conditions or other circumstances may reduce the capacity of the party obligated to make principal and interest payments on such instruments and may lead to defaults. Such non-payments and defaults may reduce the value of Fund shares and income distributions. The value of debt instruments also may decline because of concerns about the issuer’s ability to make principal and interest payments. In addition, the credit ratings of debt instruments may be lowered if the financial condition of the party obligated to make payments with respect to such instruments deteriorates. In the event of bankruptcy of the issuer of a debt instrument, the Fund could experience delays or limitations with respect to its ability to realize the benefits of any collateral securing the instrument. In order to enforce its rights in the event of a default, bankruptcy or similar situation, the Fund may be required to retain legal or similar counsel, which may increase the Fund’s operating expenses and adversely affect net asset value.

Lower Rated Investments Risk. Investments rated below investment grade and comparable unrated investments (sometimes referred to as “junk”) have speculative characteristics because of the credit risk associated with their issuers. Changes in economic conditions or other circumstances typically have a greater effect on the ability of issuers of lower rated investments to make principal and interest payments than they do on issuers of higher rated investments. An economic downturn generally leads to a higher non-payment rate, and a lower rated investment may lose significant value before a default occurs. Lower rated investments typically are subject to greater price volatility and illiquidity than higher rated investments.

Interest Rate Risk. In general, the value of income securities will fluctuate based on changes in interest rates. The value of these securities is likely to increase when interest rates fall and decline when interest rates rise. Duration measures a fixed-income security’s price sensitivity to changes in the general level of interest rates. Generally, securities with longer durations or maturities are more sensitive to changes in interest rates than securities with shorter durations or maturities, causing them to be more volatile. Conversely, fixed-income securities with shorter durations or maturities will be less volatile but may provide lower returns than fixed-income securities with longer durations or maturities. Funds with shorter average durations (including the Fund) may own individual investments that have longer durations than the average duration of the Fund. In a rising interest rate environment, the duration of income securities that have the ability to be prepaid or called by the issuer may be extended. In a declining interest rate environment, the proceeds from prepaid or maturing instruments may have to be reinvested at a lower interest rate. Certain instruments held by the Fund pay an interest rate based on the London Interbank Offered Rate (“LIBOR”), which is the average offered rate for various maturities of short-term loans between certain major international banks. LIBOR is used throughout global banking and financial industries to determine interest rates for a variety of financial instruments (such as debt instruments and derivatives) and borrowing arrangements. The ICE Benchmark Administration Limited, the administrator of LIBOR, ceased publishing certain LIBOR settings on December 31, 2021, and is expected to cease publishing the remaining LIBOR settings on June 30, 2023. Although the transition process away from LIBOR has become increasingly well defined, the impact on certain debt securities, derivatives and other financial instruments that utilize LIBOR remains uncertain. The phase-out of LIBOR may result in, among other things, increased volatility or illiquidity in markets for instruments based on LIBOR and changes in the value of such instruments.

Additional Risks of Loans. Loans are traded in a private, unregulated inter-dealer or inter-bank resale market and are generally subject to contractual restrictions that must be satisfied before a loan can be bought or sold. These restrictions may impede the Fund’s ability to buy or sell loans (thus affecting their liquidity) and may negatively impact the transaction price. See also “Market Risk” above. It also may take longer than seven days for transactions in loans to settle. Due to the possibility of an extended loan settlement process, the Fund may hold cash, sell investments or temporarily borrow from

banks or other lenders to meet short-term liquidity needs, such as to satisfy redemption requests from Fund shareholders. The types of covenants included in loan agreements generally vary depending on market conditions, the creditworthiness of the issuer, the nature of the collateral securing the loan and possibly other factors. Loans with fewer covenants that restrict activities of the borrower may provide the borrower with more flexibility to take actions that may be detrimental to the loan holders and provide fewer investor protections in the event of such actions or if covenants are breached. The Fund may experience relatively greater realized or unrealized losses or delays and expense in enforcing its rights with respect to loans with fewer restrictive covenants. Loans to entities located outside of the U.S. may have substantially different lender protections and covenants as compared to loans to U.S. entities and may involve greater risks. The Fund may have difficulties and incur expense enforcing its rights with respect to non-U.S. loans and such loans could be subject to bankruptcy laws that are materially different than in the U.S. Loans may be structured such that they are not securities under securities law, and in the event of fraud or misrepresentation by a borrower, lenders may not have the protection of the anti-fraud provisions of the federal securities laws. Loans are also subject to risks associated with other types of income investments, including credit risk and risks of lower rated investments.

Derivatives Risk. The Fund’s exposure to derivatives involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other investments. The use of derivatives can lead to losses because of adverse movements in the price or value of the security, instrument, index, currency, commodity, economic indicator or event underlying a derivative (“reference instrument”), due to failure of a counterparty or due to tax or regulatory constraints. Derivatives may create leverage in the Fund, which represents a non-cash exposure to the underlying reference instrument. Leverage can increase both the risk and return potential of the Fund. Derivatives risk may be more significant when derivatives are used to enhance return or as a substitute for a cash investment position, rather than solely to hedge the risk of a position held by the Fund. Use of derivatives involves the exercise of specialized skill and judgment, and a transaction may be unsuccessful in whole or in part because of market behavior or unexpected events. Changes in the value of a derivative (including one used for hedging) may not correlate perfectly with the underlying reference instrument. Derivative instruments traded in over-the-counter markets may be difficult to value, may be illiquid, and may be subject to wide swings in valuation caused by changes in the value of the underlying reference instrument. If a derivative’s counterparty is unable to honor its commitments, the value of Fund shares may decline and the Fund could experience delays in (or be unable to achieve) the return of collateral or other assets held by the counterparty. The loss on derivative transactions may substantially exceed the initial investment. A derivative investment also involves the risks relating to the reference instrument underlying the investment.

When-Issued and Forward Commitment Risk. Securities purchased on a when-issued or forward commitment basis are subject to the risk that when delivered they will be worth less than the agreed upon payment price.

Risks of Repurchase Agreements and Reverse Repurchase Agreements. In the event of the insolvency of the counterparty to a repurchase agreement or reverse repurchase agreement, recovery of the repurchase price owed to the Fund or, in the case of a reverse repurchase agreement, the securities sold by the Fund, may be delayed. In a repurchase agreement, such insolvency may result in a loss to the extent that the value of the purchased securities decreases during the delay or that value has otherwise not been maintained at an amount equal to the repurchase price. In a reverse repurchase agreement, the counterparty’s insolvency may result in a loss equal to the amount by which the value of the securities sold by the Fund exceeds the repurchase price payable by the Fund; if the value of the purchased securities increases during such a delay, that loss may also be increased. When the Fund enters into a reverse repurchase agreement, any fluctuations in the market value of either the securities sold to the counterparty or the securities which the Fund purchases with its proceeds from the agreement would affect the value of the Fund’s assets. As a result, such agreements may increase fluctuations in the net asset value of the Fund’s shares. Because reverse repurchase agreements may be considered to be a form of borrowing by the Fund (and a loan from the counterparty), they create leverage. If the Fund reinvests the proceeds of a reverse repurchase agreement at a rate lower than the cost of the agreement, entering into the agreement will lower the Fund’s yield.

Borrowing Risk. Borrowing cash to increase investments (sometimes referred to as “leverage”) may exaggerate the effect on the Fund’s net asset value of any increase or decrease in the value of the security purchased with the borrowing. There can be no assurance that the use of borrowings will be successful. In connection with its borrowings, the Fund will be required to maintain specified asset coverage with respect to such borrowings by applicable federal securities laws and the terms of its credit facility with the lender. The Fund may be required to dispose of portfolio investments on unfavorable terms if market fluctuations or other factors cause the required asset coverage to be less than the prescribed amount. Borrowings involve additional expense to the Fund.

Leverage Risk. Certain Fund transactions may give rise to leverage. Leverage can result from a non-cash exposure to an underlying reference instrument. Leverage can increase both the risk and return potential of the Fund. The use of leverage may cause the Fund to maintain liquid assets or liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet segregation requirements. Leverage may cause the Fund’s share price to be

more volatile than if it had not been leveraged, as certain types of leverage may exaggerate the effect of any increase or decrease in the value of the Fund’s portfolio securities. The loss on leveraged investments may substantially exceed the initial investment.

Short Sale Risk. The Fund will incur a loss as a result of a short sale if the price of the security sold short increases in value between the date of the short sale and the date on which the Fund purchases the security to replace the borrowed security. In addition, a lender may request, or market conditions may dictate, that securities sold short be returned to the lender on short notice, and the Fund may have to buy the securities sold short at an unfavorable price and/or may have to sell related long positions before it had intended to do so. The Fund may not be able to successfully implement its short sale strategy due to limited availability of desired securities or for other reasons. The Fund may also be required to pay a premium and other transaction costs, which would increase the cost of the security sold short. The amount of any gain will be decreased and the amount of any loss increased, by the amount of the premium, dividends, interest or expenses the Fund may be required to pay in connection with the short sale. Because losses on short sales arise from increases in the value of the security sold short, the Fund’s losses are potentially unlimited in a short sale transaction. Short sales could be speculative transactions and involve special risks, including greater reliance on the investment adviser’s ability to accurately anticipate the future value of a security.

Liquidity Risk. The Fund is exposed to liquidity risk when trading volume, lack of a market maker or trading partner, large position size, market conditions, or legal restrictions impair its ability to sell particular investments or to sell them at advantageous market prices. Consequently, the Fund may have to accept a lower price to sell an investment or continue to hold it or keep the position open, sell other investments to raise cash or abandon an investment opportunity, any of which could have a negative effect on the Fund’s performance. These effects may be exacerbated during times of financial or political stress.

Money Market Instrument Risk. Money market instruments may be adversely affected by market and economic events, such as a sharp rise in prevailing short-term interest rates; adverse developments in the banking industry, which issues or guarantees many money market instruments; adverse economic, political or other developments affecting issuers of money market instruments; changes in the credit quality of issuers; and default by a counterparty.

Portfolio Turnover Risk. The annual portfolio turnover rate of the Fund may exceed 100%. A mutual fund with a high turnover rate (100% or more) may generate more capital gains and may involve greater expenses (which may reduce return) than a fund with a lower rate. Capital gains distributions will be made to shareholders if offsetting capital loss carry forwards do not exist.

Risks Associated with Active Management. The success of the Fund’s investment strategy depends on portfolio management’s successful application of analytical skills and investment judgment. Active management involves subjective decisions and there is no guarantee that such decisions will produce the desired results or expected returns.

General Fund Investing Risks. The Fund is not a complete investment program and there is no guarantee that the Fund will achieve its investment objective. It is possible to lose money by investing in the Fund. The Fund is not suited for short-term trading, and investors in the Fund should be able to tolerate potentially sharp declines in value over time. Purchase and redemption activities by Fund shareholders may impact the management of the Fund and its ability to achieve its investment objective(s). In addition, the redemption by one or more large shareholders or groups of shareholders of their holdings in the Fund could have an adverse impact on the remaining shareholders in the Fund. The Fund relies on various service providers, including the investment adviser and sub-adviser, if applicable, in its operations and is susceptible to operational, information security and related events (such as public health crises, cyber or hacking attacks) that may affect the service providers or the services that they provide to the Fund. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Risk Not Insured Depository Institution

rr_RiskNotInsuredDepositoryInstitution

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

Performance Narrative

rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and how the Fund’s average annual returns over time compare with those of a broad-based securities market index. The returns in the bar chart are for Class A shares and do not reflect a sales charge. If the sales charge was reflected, the returns would be lower. Past performance (both before and after taxes) is not necessarily an indication of how the Fund will perform in the future. The Fund’s performance reflects the effects of expense reductions. Absent these reductions, performance for would have been lower. Updated Fund performance information can be obtained by visiting www.eatonvance.com.

Performance Availability Website Address

rr_PerformanceAvailabilityWebSiteAddress

www.eatonvance.com

Bar Chart Does Not Reflect Sales Loads

rr_BarChartDoesNotReflectSalesLoads

The returns in the bar chart are for Class A shares and do not reflect a sales charge. If the sales charge was reflected, the returns would be lower.

Bar Chart Closing

rr_BarChartClosingTextBlock

For the ten years ended December 31, 2022, the highest quarterly total return for Class A was 1.03% for the quarter ended March 31, 2020, and the lowest quarterly return was -2.02% for the quarter ended September 30, 2022.

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the highest historical individual federal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on a shareholder’s tax situation and the actual characterization of distributions, and may differ from those shown.

Performance Table One Class of after Tax Shown

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax returns for other Classes of shares will vary from the after-tax returns presented for Class A shares.

Performance Table Footnotes, Reason Performance Information for Class Different from Immediately Preceding Period

rr_PerformanceTableFootnotesReasonPerformanceInformationForClassDifferentFromImmediatelyPrecedingPeriod

Advisers Class performance shown above for the period prior to May 17, 2021 (commencement of operations) is the performance of Class A shares at net asset value without adjustment for Class A’s sales charge and without adjustment for any differences in the expenses of the two classes. If adjusted for such differences, returns would be different.

Average Annual Return, Caption

rr_AverageAnnualReturnCaption

Average Annual Total Return as of December 31, 2022

Prospectus [Line Items]

rr_ProspectusLineItems

One Year

rr_AverageAnnualReturnYear01

0.68%

Ten Years

rr_AverageAnnualReturnYear10

0.82%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.79%

3 Years

rr_ExpenseExampleYear03

252

10 Years

rr_ExpenseExampleYear10

978

3 Years

rr_ExpenseExampleNoRedemptionYear03

252

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 978

Five Years

rr_AverageAnnualReturnYear05

(0.01%)

Inception Date

rr_AverageAnnualReturnInceptionDate

May 17, 2021

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

^[3]

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.79%

3 Years

rr_ExpenseExampleYear03

472

10 Years

rr_ExpenseExampleYear10

1,181

3 Years

rr_ExpenseExampleNoRedemptionYear03

472

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,181

2014

rr_AnnualReturn2014

2.47%

2016

rr_AnnualReturn2016

1.21%

2018

rr_AnnualReturn2018

2.00%

2020

rr_AnnualReturn2020

2.53%

2022

rr_AnnualReturn2022

(3.28%)

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Mar. 31, 2020

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest quarterly return

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(2.02%)

Five Years

rr_AverageAnnualReturnYear05

0.01%

One Year

rr_AverageAnnualReturnYear01

(6.34%)

Ten Years

rr_AverageAnnualReturnYear10

(0.53%)

Prospectus [Line Items]

rr_ProspectusLineItems

Five Years

rr_AverageAnnualReturnYear05

(0.43%)

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.46%

Other Expenses

rr_OtherExpensesOverAssets

0.08%

1 Year

rr_ExpenseExampleYear01

$ 242

5 Years

rr_ExpenseExampleYear05

761

1 Year

rr_ExpenseExampleNoRedemptionYear01

142

5 Years

rr_ExpenseExampleNoRedemptionYear05

761

One Year

rr_AverageAnnualReturnYear01

(4.80%)

Ten Years

rr_AverageAnnualReturnYear10

0.27%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.54%

3 Years

rr_ExpenseExampleYear03

173

10 Years

rr_ExpenseExampleYear10

677

3 Years

rr_ExpenseExampleNoRedemptionYear03

173

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 677

Five Years

rr_AverageAnnualReturnYear05

0.72%

Trading Symbol

dei_TradingSymbol

ESHAX

Prospectus [Line Items]

rr_ProspectusLineItems

Risk/Return

rr_RiskReturnHeading

Eaton Vance Short Duration High Income Fund

Objective, Primary

rr_ObjectivePrimaryTextBlock

The Fund's investment objective is total return.

Expense Narrative

rr_ExpenseNarrativeTextBlock

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. Investors may also pay commissions or other fees to their financial intermediary, which are not reflected below. You may qualify for a reduced sales charge on purchases of Class A shares if you invest, or agree to invest over a 13-month period, at least $100,000 in Eaton Vance Funds. Certain financial intermediaries also may offer variations in Fund sales charges to their customers as described in Appendix A – Financial Intermediary Sales Charge Variations in this Prospectus. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 39 of this Prospectus and page 23 of the Fund’s Statement of Additional Information.

Operating Expenses Caption

rr_OperatingExpensesCaption

Annual Fund Operating Expenses (expenses you pay each year as a percentage of the value of your investment)

Portfolio Turnover

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” the 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 96% of the average value of its portfolio.

Expense Breakpoint Discounts

rr_ExpenseBreakpointDiscounts

You may qualify for a reduced sales charge on purchases of Class A shares if you invest, or agree to invest over a 13-month period, at least $100,000 in Eaton Vance Funds. Certain financial intermediaries also may offer variations in Fund sales charges to their customers as described in Appendix A – Financial Intermediary Sales Charge Variations in this Prospectus. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 39 of this Prospectus and page 23 of the Fund’s Statement of Additional Information.

Expense Example

rr_ExpenseExampleHeading

Example.

Strategy

rr_StrategyHeading

Principal Investment Strategies

Strategy Portfolio Concentration

rr_StrategyPortfolioConcentration

The Fund invests primarily in fixed-income securities rated below investment grade (commonly referred to as “junk”), including floating-rate loans and convertible securities. The Fund invests in securities rated Baa or below by Moody’s Investors Service, Inc. (“Moody’s”) or BBB and below by S&P Global Ratings (“S&P”) or Fitch Ratings (“Fitch”) and comparable rated securities, including securities rated below Caa1 by Moody’s, CCC+ by S&P or CCC by Fitch Ratings at time of purchase or are unrated and of comparable quality as determined by the investment adviser. The Fund intends to maintain a dollar-weighted average duration of three years or less. Bonds rated BBB and Baa have speculative characteristics, while lower rated bonds are predominantly speculative. The Fund may invest in securities in any ratings category, including securities rated investment grade. The Fund may invest in fixed-income securities of any maturity. The Fund may also purchase securities that make “in-kind” interest payments (“PIK”), bonds not paying current income and bonds that do not make regular interest payments. The Fund may invest in foreign and emerging market securities, which are predominantly U.S. dollar denominated and in non-U.S. dollar denominated investments. The Fund may invest in municipal obligations, senior and subordinated (“junior”) floating rate loans (“loans”) and money market instruments. The Fund is “non-diversified”, which means it may invest a greater percentage of its assets in the securities of a single issuer than a “diversified” fund.

Risk Narrative

rr_RiskNarrativeTextBlock

Market Risk. The value of investments held by the Fund may increase or decrease in response to social, economic, political, financial, public health crises or other disruptive events (whether real, expected or perceived) in the U.S. and global markets and include events such as war, natural disasters, epidemics and pandemics, terrorism, conflicts and social unrest. These events may negatively impact broad segments of businesses and populations and may exacerbate pre-existing risks to the Fund. The frequency and magnitude of resulting changes in the value of the Fund’s investments cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in reaction to changing market conditions. Monetary and/or fiscal actions taken by U.S. or foreign governments to stimulate or stabilize the global economy may not be effective and could lead to high market volatility. No active trading market may exist for certain investments held by the Fund, which may impair the ability of the Fund to sell or to realize the current valuation of such investments in the event of the need to liquidate such assets.

Lower Rated Investments Risk. Investments rated below investment grade and comparable unrated investments (sometimes referred to as “junk”) have speculative characteristics because of the credit risk associated with their issuers. Changes in economic conditions or other circumstances typically have a greater effect on the ability of issuers of lower rated investments to make principal and interest payments than they do on issuers of higher rated investments. An economic downturn generally leads to a higher non-payment rate, and a lower rated investment may lose significant value before a default occurs. Lower rated investments typically are subject to greater price volatility and illiquidity than higher rated investments.

Interest Rate Risk. In general, the value of income securities will fluctuate based on changes in interest rates. The value of these securities is likely to increase when interest rates fall and decline when interest rates rise. Duration measures the time-weighted expected cash flows of a fixed-income security, while maturity refers to the amount of time until a fixed-income security matures. Generally, securities with longer durations or maturities are more sensitive to changes in interest rates than securities with shorter durations or maturities, causing them to be more volatile. Conversely, fixed-income securities with shorter durations or maturities will be less volatile but may provide lower returns than fixed-income securities with longer durations or maturities. The Fund may own individual investments that have longer durations. The impact of interest rate changes is significantly less for floating-rate instruments that have relatively short periodic rate resets (i.e., ninety days or less). In a rising interest rate environment, the duration of income securities that have the ability to be prepaid or called by the issuer may be extended. In a declining interest rate environment, the proceeds from prepaid or maturing instruments may have to be reinvested at a lower interest rate. Certain instruments held by the Fund pay an interest rate based on the London Interbank Offered Rate (“LIBOR”), which is the average offered rate for various maturities of short-term loans between certain major international banks. LIBOR is used throughout global banking and financial industries to determine interest rates for a variety of financial instruments (such as debt instruments and derivatives) and borrowing arrangements. The ICE Benchmark Administration Limited, the administrator of LIBOR, ceased publishing certain LIBOR settings on December 31, 2021, and is expected to cease publishing the remaining LIBOR settings on June 30, 2023. Although the transition process away from LIBOR has become increasingly well defined, the impact on certain debt securities, derivatives and other financial instruments that utilize LIBOR remains uncertain. The phase-out of LIBOR may result in, among other things, increased volatility or illiquidity in markets for instruments based on LIBOR and changes in the value of such instruments.

Credit Risk. Investments in fixed income and other debt obligations, including loans (referred to below as “debt Instruments”) are subject to the risk of non-payment of scheduled principal and interest. Changes in economic conditions or other circumstances may reduce the capacity of the party obligated to make principal and interest payments on such instruments and may lead to defaults. Such non-payments and defaults may reduce the value of Fund shares and income distributions. The value of debt instruments also may decline because of concerns about the issuer’s ability to make principal and interest payments. In addition, the credit ratings of debt instruments may be lowered if the financial condition of the party obligated to make payments with respect to such instruments deteriorates. In the event of bankruptcy of the issuer of a debt instrument, the Fund could experience delays or limitations with respect to its ability to realize the benefits of any collateral securing the instrument. In order to enforce its rights in the event of a default, bankruptcy or similar situation, the Fund may be required to retain legal or similar counsel, which may increase the Fund’s operating expenses and adversely affect net asset value.

Convertible and Other Hybrid Securities Risk. Convertible and other hybrid securities (including preferred and convertible instruments) generally possess certain characteristics of both equity and debt securities. In addition to risks associated with investing in income securities, such as interest rate and credit risks, hybrid securities may be subject to issuer-specific and market risks generally applicable to equity securities. Convertible securities may also react to changes in the value of the common stock into which they convert, and are thus subject to equity investing and market risks. A convertible security may be converted at an inopportune time, which may decrease the Fund’s return.

PIK Securities Risk. Bonds and preferred stocks that make payments “in-kind” (“PIK”) and other securities that do not pay regular income distributions may experience greater volatility in response to interest rate changes and issuer developments. PIK securities generally carry higher interest rates compared to bonds that make cash payments of interest to reflect the increased risks associated with the deferral of interest payments. PIK securities may involve additional risk because the Fund receives no cash payments until the maturity date or a specified cash payment date. If the issuer of a PIK security defaults the Fund may lose its entire investment. The Fund may be required to sell investments to obtain cash needed for income distributions.

Derivatives Risk. The Fund’s exposure to derivatives involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other investments. The use of derivatives can lead to losses because of adverse movements in the price or value of the security, instrument, index, currency, commodity, economic indicator or event underlying a derivative (“reference instrument”), due to failure of a counterparty or due to tax or regulatory constraints. Derivatives may create leverage in the Fund, which represents a non-cash exposure to the underlying reference instrument. Leverage can increase both the risk and return potential of the Fund. Derivatives risk may be more significant when derivatives are used to enhance return or as a substitute for a cash investment position, rather than solely to hedge the risk of a position held by the Fund. Use of derivatives involves the exercise of specialized skill and judgment, and a transaction may be unsuccessful in whole or in part because of market behavior or unexpected events. Changes in the value of a derivative (including one used for hedging) may not correlate perfectly with the underlying reference instrument. Derivative instruments traded in over-the-counter markets may be difficult to value, may be illiquid, and may be subject to wide swings in valuation caused by changes in the value of the underlying reference instrument. If

a derivative’s counterparty is unable to honor its commitments, the value of Fund shares may decline and the Fund could experience delays in (or be unable to achieve) the return of collateral or other assets held by the counterparty. The loss on derivative transactions may substantially exceed the initial investment. A derivative investment also involves the risks relating to the reference instrument underlying the investment.

Leverage Risk. Certain Fund transactions may give rise to leverage. Leverage can result from a non-cash exposure to an underlying reference instrument. Leverage can increase both the risk and return potential of the Fund. The use of leverage may cause the Fund to maintain liquid assets or liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet segregation requirements. Leverage may cause the Fund’s share price to be more volatile than if it had not been leveraged, as certain types of leverage may exaggerate the effect of any increase or decrease in the value of the Fund’s portfolio securities. The loss on leveraged investments may substantially exceed the initial investment.

Liquidity Risk. The Fund is exposed to liquidity risk when trading volume, lack of a market maker or trading partner, large position size, market conditions, or legal restrictions impair its ability to sell particular investments or to sell them at advantageous market prices. Consequently, the Fund may have to accept a lower price to sell an investment or continue to hold it or keep the position open, sell other investments to raise cash or abandon an investment opportunity, any of which could have a negative effect on the Fund’s performance. These effects may be exacerbated during times of financial or political stress.

Foreign Investment Risk. Foreign investments can be adversely affected by political, economic and market developments abroad, including the imposition of economic and other sanctions by the United States or another country against a particular country or countries, organizations, entities and/or individuals. There may be less publicly available information about foreign issuers because they may not be subject to reporting practices, requirements or regulations comparable to those to which United States companies are subject. Adverse changes in investment regulations, capital requirements or exchange controls could adversely affect the value of the Fund's investments. Foreign markets may be smaller, less liquid and more volatile than the major markets in the United States and, as a result, Fund share values may be more volatile. Trading in foreign markets typically involves higher expense than trading in the United States. The Fund may have difficulties enforcing its legal or contractual rights in a foreign country.

Emerging Markets Investment Risk. Investment markets within emerging market countries are typically smaller, less liquid, less developed and more volatile than those in more developed markets like the United States, and may be focused in certain sectors. Emerging market securities often involve greater risks than developed market securities. The information available about an emerging market issuer may be less reliable than for comparable issuers in more developed capital markets.

Currency Risk. Exchange rates for currencies fluctuate daily. The value of foreign investments may be affected favorably or unfavorably by changes in currency exchange rates in relation to the U.S. dollar. Currency markets generally are not as regulated as securities markets and currency transactions are subject to settlement, custodial and other operational risks.

Money Market Instrument Risk. Money market instruments may be adversely affected by market and economic events, such as a sharp rise in prevailing short-term interest rates; adverse developments in the banking industry, which issues or guarantees many money market instruments; adverse economic, political or other developments affecting issuers of money market instruments; changes in the credit quality of issuers; and default by a counterparty.

Additional Risks of Loans. Loans are traded in a private, unregulated inter-dealer or inter-bank resale market and are generally subject to contractual restrictions that must be satisfied before a loan can be bought or sold. These restrictions may impede the Fund’s ability to buy or sell loans (thus affecting their liquidity) and may negatively impact the transaction price. See also “Market Risk” above. It also may take longer than seven days for transactions in loans to settle. Due to the possibility of an extended loan settlement process, the Fund may hold cash, sell investments or temporarily borrow from banks or other lenders to meet short-term liquidity needs, such as to satisfy redemption requests from Fund shareholders. The types of covenants included in loan agreements generally vary depending on market conditions, the creditworthiness of the issuer, the nature of the collateral securing the loan and possibly other factors. Loans with fewer covenants that restrict activities of the borrower may provide the borrower with more flexibility to take actions that may be detrimental to the loan holders and provide fewer investor protections in the event of such actions or if covenants are breached. The Fund may experience relatively greater realized or unrealized losses or delays and expense in enforcing its rights with respect to loans with fewer restrictive covenants. Loans to entities located outside of the U.S. may have substantially different lender protections and covenants as compared to loans to U.S. entities and may involve greater risks. The Fund may have difficulties and incur expense enforcing its rights with respect to non-U.S. loans and such loans could be subject

to bankruptcy laws that are materially different than in the U.S. Loans may be structured such that they are not securities under securities law, and in the event of fraud or misrepresentation by a borrower, lenders may not have the protection of the anti-fraud provisions of the federal securities laws. Loans are also subject to risks associated with other types of income investments, including credit risk and risks of lower rated investments.

Municipal Obligations Risk. The amount of public information available about municipal obligations is generally less than for corporate equities or bonds, meaning that the investment performance of municipal obligations may be more dependent on the analytical abilities of the investment adviser than stock or corporate bond investments. The secondary market for municipal obligations also tends to be less well-developed and less liquid than many other securities markets, which may limit the Fund’s ability to sell its municipal obligations at attractive prices. The differences between the price at which an obligation can be purchased and the price at which it can be sold may widen during periods of market distress. Less liquid obligations can become more difficult to value and be subject to erratic price movements. The increased presence of non-traditional participants (such as proprietary trading desks of investment banks and hedge funds) or the absence of traditional participants (such as individuals, insurance companies, banks and life insurance companies) in the municipal markets may lead to greater volatility in the markets because non-traditional participants may trade more frequently or in greater volume.

Issuer Non-Diversification Risk. The Fund is “non-diversified,” which means it may invest a greater percentage of its assets in the securities of a single issuer than a fund that is “diversified.” Non-diversified funds may focus their investments in a small number of issuers, making them more susceptible to risks affecting such issuers than a more diversified fund might be, and the value of the Fund's shares may be more volatile than the values of shares of more diversified funds.

Pooled Investment Vehicles Risk. Pooled investment vehicles are open- and closed-end investment companies and exchange-traded funds (“ETFs”). Pooled investment vehicles are subject to the risks of investing in the underlying securities or other investments. Shares of closed-end investment companies and ETFs may trade at a premium or discount to net asset value and are subject to secondary market trading risks. In addition, the Fund will bear a pro rata portion of the operating expenses of a pooled investment vehicle in which it invests.

Risks Associated with Active Management. The success of the Fund’s investment strategy depends on portfolio management’s successful application of analytical skills and investment judgment. Active management involves subjective decisions and there is no guarantee that such decisions will produce the desired results or expected returns.

General Fund Investing Risks. The Fund is not a complete investment program and there is no guarantee that the Fund will achieve its investment objective. It is possible to lose money by investing in the Fund. The Fund is not suited for short-term trading, and investors in the Fund should be able to tolerate potentially sharp declines in value over time. Purchase and redemption activities by Fund shareholders may impact the management of the Fund and its ability to achieve its investment objective(s). In addition, the redemption by one or more large shareholders or groups of shareholders of their holdings in the Fund could have an adverse impact on the remaining shareholders in the Fund. The Fund relies on various service providers, including the investment adviser and sub-adviser, if applicable, in its operations and is susceptible to operational, information security and related events (such as public health crises, cyber or hacking attacks) that may affect the service providers or the services that they provide to the Fund. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Risk Not Insured Depository Institution

rr_RiskNotInsuredDepositoryInstitution

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

Bar Chart and Performance Table

rr_BarChartAndPerformanceTableHeading

Performance

Performance Information Illustrates Variability of Returns

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and how the Fund’s average annual total returns over time compare with those of a broad-based securities market index.

Performance Past Does Not Indicate Future

rr_PerformancePastDoesNotIndicateFuture

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

Annual Return Caption

rr_AnnualReturnCaption

Calendar year-by-year total return

Performance Table Does Reflect Sales Loads

rr_PerformanceTableDoesReflectSalesLoads

These returns reflect the maximum current sales charge for Class A (3.25%).

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

After-tax returns are not relevant to shareholders who hold shares in tax-deferred accounts or to shares held by non-taxable entities.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Return After Taxes on Distributions for a period may be the same as Return Before Taxes for that period because no taxable distributions were made during that period. Also, Return After Taxes on Distributions and Sale of Fund Shares for a period may be greater than or equal to Return After Taxes on Distributions for the same period because of losses realized on the sale of Fund shares.

Performance Table Closing

rr_PerformanceTableClosingTextBlock

These returns reflect the maximum current sales charge for Class A (3.25%). Class A and Class I commenced operations on November 1, 2013. The Class A and Class I performance shown above for the period prior to November 1, 2013 (commencement of operations) is the performance of the SDHI Portfolio, adjusted for the sales charge that applies to Class A shares, but not adjusted for Fund expenses. If adjusted for such differences, returns would be different. ICE® BofA® indices are not for redistribution or other uses; provided “as is,” without warranties, and with no liability. Eaton Vance has prepared this report and ICE Data Indices, LLC does not endorse it, or guarantee, review, or endorse Eaton Vance’s products. BofA® is a licensed registered trademark of Bank of America Corporation in the United States and other countries. Investors cannot invest directly in an Index.

After-tax returns are calculated using the highest historical individual federal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on a shareholder’s tax situation and the actual characterization of distributions, and may differ from those shown. After-tax returns are not relevant to shareholders who hold shares in tax-deferred accounts or to shares held by non-taxable entities. After-tax returns for other Classes of shares will vary from the after-tax returns presented for Class A shares. Return After Taxes on Distributions for a period may be the same as Return Before Taxes for that period because no taxable distributions were made during that period. Also, Return After Taxes on Distributions and Sale of Fund Shares for a period may be greater than or equal to Return After Taxes on Distributions for the same period because of losses realized on the sale of Fund shares.

Index No Deduction for Fees, Expenses, Taxes

rr_IndexNoDeductionForFeesExpensesTaxes

(reflects on deduction for fees, expenses or taxes)

Five Years

rr_AverageAnnualReturnYear05

2.99%

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

3.25%

Management Fees

rr_ManagementFeesOverAssets

0.55%

Other Expenses

rr_OtherExpensesOverAssets

0.33%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.14%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

0.91%

1 Year

rr_ExpenseExampleYear01

$ 415

5 Years

rr_ExpenseExampleYear05

911

2013

rr_AnnualReturn2013

6.03%

2015

rr_AnnualReturn2015

0.05%

2017

rr_AnnualReturn2017

4.55%

2019

rr_AnnualReturn2019

8.43%

2021

rr_AnnualReturn2021

4.63%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest quarterly total return

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

5.55%

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

One Year

rr_AverageAnnualReturnYear01

(6.50%)

Life of Fund

rr_AverageAnnualReturnSinceInception

2.85%

One Year

rr_AverageAnnualReturnYear01

(8.28%)

Life of Fund

rr_AverageAnnualReturnSinceInception

1.16%

Prospectus [Line Items]

rr_ProspectusLineItems

Five Years

rr_AverageAnnualReturnYear05

0.37%

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.55%

Other Expenses

rr_OtherExpensesOverAssets

0.33%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.89%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

0.66%

3 Years

rr_ExpenseExampleYear03

261

10 Years

rr_ExpenseExampleYear10

$ 1,075

Five Years

rr_AverageAnnualReturnYear05

2.55%

Trading Symbol

dei_TradingSymbol

EVFAX

Prospectus [Line Items]

rr_ProspectusLineItems

Trading Symbol

dei_TradingSymbol

ECFAX

Prospectus [Line Items]

rr_ProspectusLineItems

Trading Symbol

dei_TradingSymbol

EFRRX

Prospectus [Line Items]

rr_ProspectusLineItems

Trading Symbol

dei_TradingSymbol

EVBLX

Prospectus [Line Items]

rr_ProspectusLineItems

Trading Symbol

dei_TradingSymbol

EIBLX

Prospectus [Line Items]

rr_ProspectusLineItems

Trading Symbol

dei_TradingSymbol

EAFHX

Prospectus [Line Items]

rr_ProspectusLineItems

Trading Symbol

dei_TradingSymbol

ECFHX

Prospectus [Line Items]

rr_ProspectusLineItems

Trading Symbol

dei_TradingSymbol

ESFHX

Prospectus [Line Items]

rr_ProspectusLineItems

Objective

rr_ObjectiveHeading

Investment Objective

Expense

rr_ExpenseHeading

Fees and Expenses of the Fund

Shareholder Fees Caption

rr_ShareholderFeesCaption

Shareholder Fees (fees paid directly from your investment)

Portfolio Turnover

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

27.00%

Expense Breakpoint, Minimum Investment Required

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

$ 100,000

Expense Example Narrative

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 indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year, that the operating expenses remain the same and that any expense reimbursement arrangement remains in place for the contractual period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy Narrative

rr_StrategyNarrativeTextBlock

Under normal circumstances, the Fund invests at least 80% of its total assets in income producing floating rate loans and other floating rate debt securities. The Fund invests primarily in senior floating rate loans of domestic and foreign borrowers (“Senior Loans”). Senior Loans typically are secured with specific collateral and have a claim on the assets and/or stock of the borrower that is senior to subordinated debtholders and stockholders of the borrower. Loans usually are of below investment grade quality and have below investment grade credit ratings, such ratings are associated with securities having high risk, speculative characteristics (sometimes referred to as “junk”). The Fund currently borrows for the purpose of acquiring additional income-producing investments (referred to as “leverage”).

The Fund may also invest in secured and unsecured subordinated loans, second lien loans and subordinated bridge loans (collectively, “Junior Loans”), other floating rate debt securities, fixed-income debt obligations and money market instruments. Other floating rate debt securities, fixed-income debt securities and money market instruments may include: bonds, notes and debentures issued by corporations; debt securities issued or guaranteed by the U.S. Government or one of its agencies or instrumentalities; and commercial paper. Money market instruments with a remaining maturity of less than 60 days are deemed floating rate debt securities. Senior Loans and Junior Loans are referred to together herein as “loans.”

The Fund may invest up to 35% of its net assets in foreign Senior Loans. Foreign Senior Loans must be denominated in U.S. dollars, euros, British pounds, Swiss francs, Canadian dollars, or Australian dollars. The Fund may engage in derivative transactions (such as futures contracts and options thereon, forward foreign currency exchange contracts and other currency hedging strategies, and interest rate swaps) to seek to hedge against fluctuations in currency exchange rates and interest rates. Except as required by applicable regulation, there is no stated limit on the Fund’s use of derivatives for such purposes.

The investment adviser seeks to maintain broad borrower and industry diversification among the Fund’s loans. When selecting loans, the investment adviser seeks to implement a systematic risk-weighted approach that utilizes fundamental analysis of risk/return characteristics. Loans may be sold, if in the opinion of the investment adviser, the risk-return profile deteriorates or to pursue more attractive investment opportunities. Preservation of capital is considered when consistent with the Fund’s investment objective. The portfolio managers may also consider financially material environmental, social and governance (“ESG”) factors in evaluating an issuer. These considerations may be taken into account alongside other fundamental research in the investment selection process.

The Fund currently invests its assets in the Portfolio, a separate registered investment company with the same investment objective and policies as the Fund.

Risk

rr_RiskHeading

Principal Risks

Risk Lose Money

rr_RiskLoseMoney

The Fund is not a complete investment program and there is no guarantee that the Fund will achieve its investment objective. It is possible to lose money by investing in the Fund.

Bar Chart and Performance Table

rr_BarChartAndPerformanceTableHeading

Performance

Performance Information Illustrates Variability of Returns

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and how the Fund’s average annual returns over time compare with those of a broad-based securities market index.

Performance Past Does Not Indicate Future

rr_PerformancePastDoesNotIndicateFuture

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

Annual Return Caption

rr_AnnualReturnCaption

Calendar year-by-year total return

Performance Table Does Reflect Sales Loads

rr_PerformanceTableDoesReflectSalesLoads

These returns reflect the maximum sales charge for Class A (3.25%) and any applicable contingent deferred sales charge (“CDSC”) for Class C.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

After-tax returns are not relevant to shareholders who hold Fund shares in tax-deferred accounts or to shares held by non-taxable entities.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Return After Taxes on Distributions for a period may be the same as Return Before Taxes for that period because no taxable distributions were made during that period. Also, Return After Taxes on Distributions and Sale of Fund Shares for a period may be greater than or equal to Return Before Taxes and/or Return After Taxes on Distributions for the same period because of losses realized on the sale of Fund shares.

Performance Table Closing

rr_PerformanceTableClosingTextBlock

These returns reflect the maximum sales charge for Class A (3.25%) and any applicable contingent deferred sales charge (“CDSC”) for Class C. Effective November 5, 2020, Class C shares automatically convert to Class A shares eight years after purchase. The average annual total returns listed for Class C reflect conversion to Class A shares after eight years. Prior to November 5, 2020, Class C shares automatically converted to Class A shares ten years after purchase. The Class R6 performance shown above for the period prior to May 31, 2019 (commencement of operations) is the performance of Class I shares at net asset value without adjustment for any differences in the expenses of the two classes. If adjusted for such differences returns would be different. Morningstar® LSTA® Leveraged Loan Index is a product of Morningstar, Inc. (“Morningstar”) licensed for use by Eaton Vance. Morningstar® is a registered trademark of Morningstar licensed for certain use by Eaton Vance. Loan Syndications and Trading Association® and LSTA® are trademarks of the LSTA licensed for certain use by Morningstar, and further sublicensed by Morningstar for certain use by Eaton Vance. Neither Morningstar nor LSTA guarantees the accuracy and/or completeness of the Morningstar® LSTA® US Leveraged Loan Index or any data included therein, and shall have no liability for any errors, omissions, or interruptions therein. Investors cannot invest directly in an Index.

After-tax returns are calculated using the highest historical individual federal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on a shareholder’s tax situation and the actual characterization of distributions, and may differ from those shown. After-tax returns are not relevant to shareholders who hold Fund shares in tax-deferred accounts or to shares held by non-taxable entities. After-tax returns for other Classes of shares will vary from the after-tax returns presented for Class A shares. Return After Taxes on Distributions for a period may be the same as Return Before Taxes for that period because no taxable distributions were made during that period. Also, Return After Taxes on Distributions and Sale of Fund Shares for a period may be greater than or equal to Return Before Taxes and/or Return After Taxes on Distributions for the same period because of losses realized on the sale of Fund shares.

Index No Deduction for Fees, Expenses, Taxes

rr_IndexNoDeductionForFeesExpensesTaxes

(reflects no deduction for fees, expenses or taxes)

Five Years

rr_AverageAnnualReturnYear05

3.31%

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.59%

Other Expenses

rr_OtherExpensesOverAssets

0.57%

^[7]

1 Year

rr_ExpenseExampleYear01

$ 144

5 Years

rr_ExpenseExampleYear05

771

1 Year

rr_ExpenseExampleNoRedemptionYear01

144

5 Years

rr_ExpenseExampleNoRedemptionYear05

771

One Year

rr_AverageAnnualReturnYear01

(3.25%)

Ten Years

rr_AverageAnnualReturnYear10

3.32%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

^[8]

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.41%

3 Years

rr_ExpenseExampleYear03

757

10 Years

rr_ExpenseExampleYear10

1,961

3 Years

rr_ExpenseExampleNoRedemptionYear03

757

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,961

2014

rr_AnnualReturn2014

0.69%

2016

rr_AnnualReturn2016

12.67%

2018

rr_AnnualReturn2018

0.12%

2020

rr_AnnualReturn2020

1.63%

2022

rr_AnnualReturn2022

(3.14%)

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2020

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest quarterly return

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(15.79%)

Five Years

rr_AverageAnnualReturnYear05

1.71%

One Year

rr_AverageAnnualReturnYear01

(8.33%)

Ten Years

rr_AverageAnnualReturnYear10

1.00%

Prospectus [Line Items]

rr_ProspectusLineItems

Five Years

rr_AverageAnnualReturnYear05

0.37%

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.59%

Other Expenses

rr_OtherExpensesOverAssets

0.57%

^[7]

1 Year

rr_ExpenseExampleYear01

$ 294

5 Years

rr_ExpenseExampleYear05

1,032

1 Year

rr_ExpenseExampleNoRedemptionYear01

194

5 Years

rr_ExpenseExampleNoRedemptionYear05

1,032

One Year

rr_AverageAnnualReturnYear01

(4.65%)

Ten Years

rr_AverageAnnualReturnYear10

2.93%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.16%

3 Years

rr_ExpenseExampleYear03

368

10 Years

rr_ExpenseExampleYear10

1,409

3 Years

rr_ExpenseExampleNoRedemptionYear03

368

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,409

Five Years

rr_AverageAnnualReturnYear05

2.63%

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.59%

Other Expenses

rr_OtherExpensesOverAssets

0.51%

^[7]

1 Year

rr_ExpenseExampleYear01

$ 112

5 Years

rr_ExpenseExampleYear05

606

1 Year

rr_ExpenseExampleNoRedemptionYear01

112

5 Years

rr_ExpenseExampleNoRedemptionYear05

606

One Year

rr_AverageAnnualReturnYear01

(2.96%)

Ten Years

rr_AverageAnnualReturnYear10

3.60%

Risk/Return

rr_RiskReturnHeading

Eaton Vance Floating-Rate Fund

Objective, Primary

rr_ObjectivePrimaryTextBlock

The Fund's investment objective is to provide a high level of current income.

Expense Narrative

rr_ExpenseNarrativeTextBlock

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. Investors may also pay commissions or other fees to their financial intermediary, which are not reflected below. You may qualify for a reduced sales charge on purchases of Class A shares if you invest, or agree to invest over a 13-month period, at least $100,000 in Eaton Vance funds. Certain financial intermediaries also may offer variations in Fund sales charges to their customers as described in Appendix A – Financial Intermediary Sales Charge Variations in this Prospectus. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 44 of this Prospectus and page 25 of the Fund’s Statement of Additional Information.

Operating Expenses Caption

rr_OperatingExpensesCaption

Annual Fund Operating Expenses (expenses you pay each year as a percentage of the value of your investment)

^[9]

Portfolio Turnover

rr_PortfolioTurnoverTextBlock

The Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” the 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 Portfolio's portfolio turnover rate was 27% of the average value of its portfolio.

Expense Breakpoint Discounts

rr_ExpenseBreakpointDiscounts

You may qualify for a reduced sales charge on purchases of Class A shares if you invest, or agree to invest over a 13-month period, at least $100,000 in Eaton Vance funds. Certain financial intermediaries also may offer variations in Fund sales charges to their customers as described in Appendix A – Financial Intermediary Sales Charge Variations in this Prospectus. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 44 of this Prospectus and page 25 of the Fund’s Statement of Additional Information.

Expense Example

rr_ExpenseExampleHeading

Example.

Strategy

rr_StrategyHeading

Principal Investment Strategies

Strategy Portfolio Concentration

rr_StrategyPortfolioConcentration

Under normal circumstances, the Fund invests at least 80% of its total assets in income producing floating rate loans and other floating rate debt securities. The Fund invests primarily in senior floating rate loans of domestic and foreign borrowers (“Senior Loans”). Senior Loans typically are secured with specific collateral and have a claim on the assets and/or stock of the borrower that is senior to subordinated debtholders and stockholders of the borrower. Loans usually are of below investment grade quality and have below investment grade credit ratings, such ratings are associated with securities having high risk, speculative characteristics (sometimes referred to as “junk”).

Risk Narrative

rr_RiskNarrativeTextBlock

Market Risk. The value of investments held by the Fund may increase or decrease in response to social, economic, political, financial, public health crises or other disruptive events (whether real, expected or perceived) in the U.S. and global markets and include events such as war, natural disasters, epidemics and pandemics, terrorism, conflicts and social unrest. These events may negatively impact broad segments of businesses and populations and may exacerbate pre-existing risks to the Fund. The frequency and magnitude of resulting changes in the value of the Fund’s investments cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in reaction to changing market conditions. Monetary and/or fiscal actions taken by U.S. or foreign governments to stimulate or stabilize the global economy may not be effective and could lead to high market volatility. No active trading market may exist for certain investments held by the Fund, which may impair the ability of the Fund to sell or to realize the current valuation of such investments in the event of the need to liquidate such assets.

Credit Risk. Investments in loans and other debt obligations (referred to below as “debt instruments”) are subject to the risk of non-payment of scheduled principal and interest. Changes in economic conditions or other circumstances may reduce the capacity of the party obligated to make principal and interest payments on such instruments and may lead to defaults. Such non-payments and defaults may reduce the value of Fund shares and income distributions. The value of debt instruments also may decline because of concerns about the issuer’s ability to make principal and interest payments. In addition, the credit ratings of debt instruments may be lowered if the financial condition of the party obligated to make payments with respect to such instruments deteriorates. In the event of bankruptcy of the issuer of a debt instrument, the Fund could experience delays or limitations with respect to its ability to realize the benefits of any collateral securing the instrument. In order to enforce its rights in the event of a default, bankruptcy or similar situation, the Fund may be required to retain legal or similar counsel, which may increase the Fund’s operating expenses and adversely affect net asset value. Due to their lower place in the borrower’s capital structure, Junior Loans involve a higher degree of overall risk than Senior Loans to the same borrower.

Additional Risks of Loans. Loans are traded in a private, unregulated inter-dealer or inter-bank resale market and are generally subject to contractual restrictions that must be satisfied before a loan can be bought or sold. These restrictions may impede the Fund’s ability to buy or sell loans (thus affecting their liquidity) and may negatively impact the transaction price. See also “Market Risk” above. It also may take longer than seven days for transactions in loans to settle. Due to the possibility of an extended loan settlement process, the Fund may hold cash, sell investments or temporarily borrow from banks or other lenders to meet short-term liquidity needs, such as to satisfy redemption requests from Fund shareholders. The types of covenants included in loan agreements generally vary depending on market conditions, the creditworthiness of the issuer, the nature of the collateral securing the loan and possibly other factors. Loans with fewer covenants that restrict activities of the borrower may provide the borrower with more flexibility to take actions that may be detrimental to the loan holders and provide fewer investor protections in the event of such actions or if covenants are breached. The Fund may experience relatively greater realized or unrealized losses or delays and expense in enforcing its rights with respect to loans with fewer restrictive covenants. Loans to entities located outside of the U.S. may have substantially different lender protections and covenants as compared to loans to U.S. entities and may involve greater risks. The Fund may have difficulties and incur expense enforcing its rights with respect to non-U.S. loans and such loans could be subject to bankruptcy laws that are materially different than in the U.S. Loans may be structured such that they are not securities under securities law, and in the event of fraud or misrepresentation by a borrower, lenders may not have the protection of the anti-fraud provisions of the federal securities laws. Loans are also subject to risks associated with other types of income investments, including credit risk and risks of lower rated investments.

Lower Rated Investments Risk. Investments rated below investment grade and comparable unrated investments (sometimes referred to as “junk”) have speculative characteristics because of the credit risk associated with their issuers. Changes in economic conditions or other circumstances typically have a greater effect on the ability of issuers of lower rated investments to make principal and interest payments than they do on issuers of higher rated investments. An economic downturn generally leads to a higher non-payment rate, and a lower rated investment may lose significant value before a default occurs. Lower rated investments typically are subject to greater price volatility and illiquidity than higher rated investments.

Interest Rate Risk. In general, the value of income securities will fluctuate based on changes in interest rates. The value of these securities is likely to increase when interest rates fall and decline when interest rates rise. Duration measures the time-weighted expected cash flows of a fixed-income security, while maturity refers to the amount of time until a fixed-income security matures. Generally, securities with longer durations or maturities are more sensitive to changes in interest rates than securities with shorter durations or maturities, causing them to be more volatile. Conversely, fixed-income securities with shorter durations or maturities will be less volatile but may provide lower returns than fixed-income securities with longer durations or maturities. The impact of interest rate changes is significantly less for floating-rate instruments that have relatively short periodic rate resets (e.g., ninety days or less). In a rising interest rate environment, the duration of income securities that have the ability to be prepaid or called by the issuer may be extended. In a declining interest rate environment, the proceeds from prepaid or maturing instruments may have to be reinvested at a lower interest rate.

LIBOR Risk. The London Interbank Offered Rate or LIBOR is used throughout global banking and financial industries to determine interest rates for a variety of financial instruments (such as debt instruments and derivatives) and borrowing arrangements. The ICE Benchmark Administration Limited, the administrator of LIBOR, ceased publishing certain LIBOR settings on December 31, 2021, and is expected to cease publishing the remaining LIBOR settings on June 30, 2023. The Fund has exposure to LIBOR-based instruments. Although the transition process away from LIBOR has become increasingly well defined, the impact on certain debt securities, derivatives and other financial instruments that utilize LIBOR remains uncertain. The transition process may involve, among other things, increased volatility or illiquidity in markets for instruments that currently rely on LIBOR, such as floating-rate debt obligations. Any effects of the transition away from LIBOR and the adoption of alternative reference rates, as well as other unforeseen effects, could result in losses to the Fund, and such effects may occur prior to the anticipated discontinuation of the remaining LIBOR settings in 2023. Furthermore, the risks associated with the discontinuation of LIBOR and transition to replacement rates may be exacerbated if an orderly transition to an alternative reference rate is not completed in a timely manner.

Foreign Investment Risk. Foreign investments can be adversely affected by political, economic and market developments abroad, including the imposition of economic and other sanctions by the United States or another country against a particular country or countries, organizations, entities and/or individuals. There may be less publicly available information about foreign issuers because they may not be subject to reporting practices, requirements or regulations comparable to those to which United States companies are subject. Adverse changes in investment regulations, capital requirements or exchange controls could adversely affect the value of the Fund's investments. Foreign markets may be smaller, less liquid and more volatile than the major markets in the United States and, as a result, Fund share values may

be more volatile. Trading in foreign markets typically involves higher expense than trading in the United States. The Fund may have difficulties enforcing its legal or contractual rights in a foreign country.

Currency Risk. Exchange rates for currencies fluctuate daily. The value of foreign investments may be affected favorably or unfavorably by changes in currency exchange rates in relation to the U.S. dollar. Currency markets generally are not as regulated as securities markets and currency transactions are subject to settlement, custodial and other operational risks.

U.S. Government Securities Risk. Although certain U.S. Government-sponsored agencies (such as the Federal Home Loan Mortgage Corporation and the Federal National Mortgage Association) may be chartered or sponsored by acts of Congress, their securities are neither issued nor guaranteed by the U.S. Treasury. U.S. Treasury securities generally have a lower return than other obligations because of their higher credit quality and market liquidity.

Money Market Instrument Risk. Money market instruments may be adversely affected by market and economic events, such as a sharp rise in prevailing short-term interest rates; adverse developments in the banking industry, which issues or guarantees many money market instruments; adverse economic, political or other developments affecting issuers of money market instruments; changes in the credit quality of issuers; and default by a counterparty.

Derivatives Risk. The Fund’s exposure to derivatives involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other investments. The use of derivatives can lead to losses because of adverse movements in the price or value of the security, instrument, index, currency, commodity, economic indicator or event underlying a derivative (“reference instrument”), due to failure of a counterparty or due to tax or regulatory constraints. Derivatives may create leverage in the Fund, which represents a non-cash exposure to the underlying reference instrument. Leverage can increase both the risk and return potential of the Fund. Derivatives risk may be more significant when derivatives are used to enhance return or as a substitute for a cash investment position, rather than solely to hedge the risk of a position held by the Fund. Use of derivatives involves the exercise of specialized skill and judgment, and a transaction may be unsuccessful in whole or in part because of market behavior or unexpected events. Changes in the value of a derivative (including one used for hedging) may not correlate perfectly with the underlying reference instrument. Derivative instruments traded in over-the-counter markets may be difficult to value, may be illiquid, and may be subject to wide swings in valuation caused by changes in the value of the underlying reference instrument. If a derivative’s counterparty is unable to honor its commitments, the value of Fund shares may decline and the Fund could experience delays in (or be unable to achieve) the return of collateral or other assets held by the counterparty. The loss on derivative transactions may substantially exceed the initial investment. A derivative investment also involves the risks relating to the reference instrument underlying the investment.

Liquidity Risk. The Fund is exposed to liquidity risk when trading volume, lack of a market maker or trading partner, large position size, market conditions, or legal restrictions impair its ability to sell particular investments or to sell them at advantageous market prices. Consequently, the Fund may have to accept a lower price to sell an investment or continue to hold it or keep the position open, sell other investments to raise cash or abandon an investment opportunity, any of which could have a negative effect on the Fund’s performance. These effects may be exacerbated during times of financial or political stress.

Investing in a Portfolio. The Fund invests its assets in the Portfolio. This enables the Fund to pool its assets with other investors that also invest in the same Portfolio, resulting in efficiencies in management and administration that can lower the Fund’s costs and enhance shareholder returns. The ability of the Fund operating in a hub and spoke structure to meet its investment objective is directly related to the ability of the corresponding Portfolio to meet its objective. Contribution and withdrawal activities by other Portfolio investors may impact the management of the Portfolio and its ability to achieve its investment objective.

Risks Associated with Active Management. The success of the Fund’s investment strategy depends on portfolio management’s successful application of analytical skills and investment judgment. Active management involves subjective decisions and there is no guarantee that such decisions will produce the desired results or expected returns.

General Fund Investing Risks. The Fund is not a complete investment program and there is no guarantee that the Fund will achieve its investment objective. It is possible to lose money by investing in the Fund. The Fund is designed to be a long-term investment vehicle and is not suited for short-term trading. Investors in the Fund should have a long-term investment perspective and be able to tolerate potentially sharp declines in value. Purchase and redemption activities by Fund shareholders may impact the management of the Fund and its ability to achieve its investment objective(s). In addition, the redemption by one or more large shareholders or groups of shareholders of their holdings in the Fund could have an adverse impact on the remaining shareholders in the Fund. The Fund relies on various service providers, including the investment adviser and sub-adviser, if applicable, in its operations and is susceptible to operational, information security and related events (such as public health crises, cyber or hacking attacks) that may affect the service

providers or the services that they provide to the Fund. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Risk Not Insured Depository Institution

rr_RiskNotInsuredDepositoryInstitution

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

Performance Narrative

rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and how the Fund’s average annual returns over time compare with those of a broad-based securities market index. The returns in the bar chart are for Class A shares and do not reflect a sales charge. If the sales charge was reflected, the returns would be lower. Past performance (both before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated Fund performance information can be obtained by visiting www.eatonvance.com.

Performance Availability Website Address

rr_PerformanceAvailabilityWebSiteAddress

www.eatonvance.com

Bar Chart Does Not Reflect Sales Loads

rr_BarChartDoesNotReflectSalesLoads

The returns in the bar chart are for Class A shares and do not reflect a sales charge. If the sales charge was reflected, the returns would be lower.

Bar Chart Closing

rr_BarChartClosingTextBlock

For the ten years ended December 31, 2022, the highest quarterly total return for Class A was 8.34% for the quarter ended June 30, 2020, and the lowest quarterly return was -12.03% for the quarter ended March 31, 2020.

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the highest historical individual federal income tax rate and do not reflect the impact of state and local taxes. Actual after-tax returns depend on a shareholder’s tax situation and the actual characterization of distributions, and may differ from those shown.

Performance Table One Class of after Tax Shown

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax returns for other Classes of shares will vary from the after-tax returns presented for Class A shares.

Performance Table Footnotes, Reason Performance Information for Class Different from Immediately Preceding Period

rr_PerformanceTableFootnotesReasonPerformanceInformationForClassDifferentFromImmediatelyPrecedingPeriod

The Class R6 performance shown above for the period prior to December 1, 2016 (commencement of operations) is the performance of Class I shares at net asset value without adjustment for any differences in the expenses of the two classes. If adjusted for such differences, returns would be different.

Average Annual Return, Caption

rr_AverageAnnualReturnCaption

Average Annual Total Return as of December 31, 2022

Prospectus [Line Items]

rr_ProspectusLineItems

One Year

rr_AverageAnnualReturnYear01

(0.60%)

Ten Years

rr_AverageAnnualReturnYear10

3.67%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.01%

1 Year

rr_ExpenseExampleYear01

$ 104

5 Years

rr_ExpenseExampleYear05

563

1 Year

rr_ExpenseExampleNoRedemptionYear01

104

5 Years

rr_ExpenseExampleNoRedemptionYear05

563

One Year

rr_AverageAnnualReturnYear01

(2.49%)

Ten Years

rr_AverageAnnualReturnYear10

2.82%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

^[11]

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.01%

1 Year

rr_ExpenseExampleYear01

$ 426

5 Years

rr_ExpenseExampleYear05

870

1 Year

rr_ExpenseExampleNoRedemptionYear01

426

5 Years

rr_ExpenseExampleNoRedemptionYear05

870

2013

rr_AnnualReturn2013

4.54%

2015

rr_AnnualReturn2015

(1.91%)

2017

rr_AnnualReturn2017

4.08%

2019

rr_AnnualReturn2019

6.84%

2021

rr_AnnualReturn2021

4.02%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest quarterly total return

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

8.34%

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

One Year

rr_AverageAnnualReturnYear01

(5.80%)

Ten Years

rr_AverageAnnualReturnYear10

2.48%

Prospectus [Line Items]

rr_ProspectusLineItems

Five Years

rr_AverageAnnualReturnYear05

(0.17%)

One Year

rr_AverageAnnualReturnYear01

(3.43%)

Ten Years

rr_AverageAnnualReturnYear10

1.11%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

1.00%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.01%

1 Year

rr_ExpenseExampleYear01

$ 280

5 Years

rr_ExpenseExampleYear05

959

1 Year

rr_ExpenseExampleNoRedemptionYear01

180

5 Years

rr_ExpenseExampleNoRedemptionYear05

959

One Year

rr_AverageAnnualReturnYear01

(4.16%)

Ten Years

rr_AverageAnnualReturnYear10

2.21%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.01%

1 Year

rr_ExpenseExampleYear01

$ 79

5 Years

rr_ExpenseExampleYear05

428

1 Year

rr_ExpenseExampleNoRedemptionYear01

79

5 Years

rr_ExpenseExampleNoRedemptionYear05

428

One Year

rr_AverageAnnualReturnYear01

(2.36%)

Ten Years

rr_AverageAnnualReturnYear10

3.08%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.01%

1 Year

rr_ExpenseExampleYear01

$ 74

5 Years

rr_ExpenseExampleYear05

401

1 Year

rr_ExpenseExampleNoRedemptionYear01

74

5 Years

rr_ExpenseExampleNoRedemptionYear05

401

One Year

rr_AverageAnnualReturnYear01

(2.30%)

Ten Years

rr_AverageAnnualReturnYear10

3.12%

Risk/Return

rr_RiskReturnHeading

Eaton Vance Floating-Rate & High Income Fund

Objective, Primary

rr_ObjectivePrimaryTextBlock

The Fund's investment objective is to provide a high level of current income.

Expense Narrative

rr_ExpenseNarrativeTextBlock

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. Investors may also pay commissions or other fees to their financial intermediary, which are not reflected below. You may qualify for a reduced sales charge on purchases of Class A shares if you invest, or agree to invest over a 13-month period, at least $100,000 in Eaton Vance funds. Certain financial intermediaries also may offer variations in Fund sales charges to their customers as described in Appendix A – Financial Intermediary Sales Charge Variations in this Prospectus. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 44 of this Prospectus and page 25 of the Fund’s Statement of Additional Information.

Operating Expenses Caption

rr_OperatingExpensesCaption

Annual Fund Operating Expenses (expenses you pay each year as a percentage of the value of your investment)

^[12]

Portfolio Turnover

rr_PortfolioTurnoverTextBlock

The Fund and the Portfolios in which it invests (see below) pay transaction costs, such as commissions, when they buy and sell securities (or “turn over” the 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 24% of the average value of its portfolio. The Fund's portfolio turnover rate is based on the Fund's contributions to and withdrawals from the Portfolios and excludes the investment activity of the Portfolios.

Expense Breakpoint Discounts

rr_ExpenseBreakpointDiscounts

You may qualify for a reduced sales charge on purchases of Class A shares if you invest, or agree to invest over a 13-month period, at least $100,000 in Eaton Vance funds. Certain financial intermediaries also may offer variations in Fund sales charges to their customers as described in Appendix A – Financial Intermediary Sales Charge Variations in this Prospectus. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 44 of this Prospectus and page 25 of the Fund’s Statement of Additional Information.

Expense Example

rr_ExpenseExampleHeading

Example.

Strategy

rr_StrategyHeading

Principal Investment Strategies

Strategy Portfolio Concentration

rr_StrategyPortfolioConcentration

Under normal circumstances, the Fund invests at least 80% of its total assets in a combination of income producing floating rate loans and other floating rate debt securities and high yield corporate bonds. The Fund may not invest more than 20% of its total assets in unsecured high yield corporate bonds. The Fund invests primarily in senior floating rate loans of domestic and foreign borrowers (“Senior Loans”). The Fund secondarily invests in high yield, high risk corporate bonds. Senior Loans typically are secured with specific collateral and have a claim on the assets and/or stock of the borrower that is senior to subordinated debtholders and stockholders of the borrower. High yield corporate bonds are, and loans usually are of below investment grade quality and have below investment grade credit ratings, such ratings are associated with securities having high risk, speculative characteristics (sometimes referred to as “junk”).

Risk Narrative

rr_RiskNarrativeTextBlock

Market Risk. The value of investments held by the Fund may increase or decrease in response to social, economic, political, financial, public health crises or other disruptive events (whether real, expected or perceived) in the U.S. and global markets and include events such as war, natural disasters, epidemics and pandemics, terrorism, conflicts and social unrest. These events may negatively impact broad segments of businesses and populations and may exacerbate pre-existing risks to the Fund. The frequency and magnitude of resulting changes in the value of the Fund’s investments cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in reaction to changing market conditions. Monetary and/or fiscal actions taken by U.S. or foreign governments to stimulate or stabilize the global economy may not be effective and could lead to

high market volatility. No active trading market may exist for certain investments, which may impair the ability of the Fund to sell or to realize the current valuation of such investments in the event of the need to liquidate such assets.

Credit Risk. Investments in loans and other debt obligations (referred to below as “debt instruments”) are subject to the risk of non-payment of scheduled principal and interest. Changes in economic conditions or other circumstances may reduce the capacity of the party obligated to make principal and interest payments on such instruments and may lead to defaults. Such non-payments and defaults may reduce the value of Fund shares and income distributions. The value of debt instruments also may decline because of concerns about the issuer’s ability to make principal and interest payments. In addition, the credit ratings of debt instruments may be lowered if the financial condition of the party obligated to make payments with respect to such instruments deteriorates. In the event of bankruptcy of the issuer of a debt instrument, the Fund could experience delays or limitations with respect to its ability to realize the benefits of any collateral securing the instrument. In order to enforce its rights in the event of a default, bankruptcy or similar situation, the Fund may be required to retain legal or similar counsel, which may increase the Fund’s operating expenses and adversely affect net asset value. Due to their lower place in the borrower’s capital structure, Junior Loans involve a higher degree of overall risk than Senior Loans to the same borrower.

Additional Risks of Loans. Loans are traded in a private, unregulated inter-dealer or inter-bank resale market and are generally subject to contractual restrictions that must be satisfied before a loan can be bought or sold. These restrictions may impede the Fund’s ability to buy or sell loans (thus affecting their liquidity) and may negatively impact the transaction price. See also “Market Risk” above. It also may take longer than seven days for transactions in loans to settle. Due to the possibility of an extended loan settlement process, the Fund may hold cash, sell investments or temporarily borrow from banks or other lenders to meet short-term liquidity needs, such as to satisfy redemption requests from Fund shareholders. The types of covenants included in loan agreements generally vary depending on market conditions, the creditworthiness of the issuer, the nature of the collateral securing the loan and possibly other factors. Loans with fewer covenants that restrict activities of the borrower may provide the borrower with more flexibility to take actions that may be detrimental to the loan holders and provide fewer investor protections in the event of such actions or if covenants are breached. The Fund may experience relatively greater realized or unrealized losses or delays and expense in enforcing its rights with respect to loans with fewer restrictive covenants. Loans to entities located outside of the U.S. may have substantially different lender protections and covenants as compared to loans to U.S. entities and may involve greater risks. The Fund may have difficulties and incur expense enforcing its rights with respect to non-U.S. loans and such loans could be subject to bankruptcy laws that are materially different than in the U.S. Loans may be structured such that they are not securities under securities law, and in the event of fraud or misrepresentation by a borrower, lenders may not have the protection of the anti-fraud provisions of the federal securities laws. Loans are also subject to risks associated with other types of income investments, including credit risk and risks of lower rated investments.

Lower Rated Investments Risk. Investments rated below investment grade and comparable unrated investments (sometimes referred to as “junk”) have speculative characteristics because of the credit risk associated with their issuers. Changes in economic conditions or other circumstances typically have a greater effect on the ability of issuers of lower rated investments to make principal and interest payments than they do on issuers of higher rated investments. An economic downturn generally leads to a higher non-payment rate, and a lower rated investment may lose significant value before a default occurs. Lower rated investments typically are subject to greater price volatility and illiquidity than higher rated investments.

Interest Rate Risk. In general, the value of income securities will fluctuate based on changes in interest rates. The value of these securities is likely to increase when interest rates fall and decline when interest rates rise. Duration measures the time-weighted expected cash flows of a fixed-income security, while maturity refers to the amount of time until a fixed-income security matures. Generally, securities with longer durations or maturities are more sensitive to changes in interest rates than securities with shorter durations or maturities, causing them to be more volatile. Conversely, fixed-income securities with shorter durations or maturities will be less volatile but may provide lower returns than fixed-income securities with longer durations or maturities. The impact of interest rate changes is significantly less for floating-rate instruments that have relatively short periodic rate resets (e.g., ninety days or less). In a rising interest rate environment, the duration of income securities that have the ability to be prepaid or called by the issuer may be extended. In a declining interest rate environment, the proceeds from prepaid or maturing instruments may have to be reinvested at a lower interest rate.

LIBOR Risk. The London Interbank Offered Rate or LIBOR is used throughout global banking and financial industries to determine interest rates for a variety of financial instruments (such as debt instruments and derivatives) and borrowing arrangements. The ICE Benchmark Administration Limited, the administrator of LIBOR, ceased publishing certain LIBOR settings on December 31, 2021, and is expected to cease publishing the remaining LIBOR settings on June 30, 2023. The Fund has exposure to LIBOR-based instruments. Although the transition process away from LIBOR has become increasingly well defined, the impact on certain debt securities, derivatives and other financial instruments that utilize

LIBOR remains uncertain. The transition process may involve, among other things, increased volatility or illiquidity in markets for instruments that currently rely on LIBOR, such as floating-rate debt obligations. Any effects of the transition away from LIBOR and the adoption of alternative reference rates, as well as other unforeseen effects, could result in losses to the Fund, and such effects may occur prior to the anticipated discontinuation of the remaining LIBOR settings in 2023. Furthermore, the risks associated with the discontinuation of LIBOR and transition to replacement rates may be exacerbated if an orderly transition to an alternative reference rate is not completed in a timely manner.

Foreign Investment Risk. Foreign investments can be adversely affected by political, economic and market developments abroad, including the imposition of economic and other sanctions by the United States or another country against a particular country or countries, organizations, entities and/or individuals. There may be less publicly available information about foreign issuers because they may not be subject to reporting practices, requirements or regulations comparable to those to which United States companies are subject. Adverse changes in investment regulations, capital requirements or exchange controls could adversely affect the value of the Fund's investments. Foreign markets may be smaller, less liquid and more volatile than the major markets in the United States and, as a result, Fund share values may be more volatile. Trading in foreign markets typically involves higher expense than trading in the United States. The Fund may have difficulties enforcing its legal or contractual rights in a foreign country.

Emerging Markets Investment Risk. Investment markets within emerging market countries are typically smaller, less liquid, less developed and more volatile than those in more developed markets like the United States, and may be focused in certain sectors. Emerging market securities often involve greater risks than developed market securities. The information available about an emerging market issuer may be less reliable than for comparable issuers in more developed capital markets.

Currency Risk. Exchange rates for currencies fluctuate daily. The value of foreign investments may be affected favorably or unfavorably by changes in currency exchange rates in relation to the U.S. dollar. Currency markets generally are not as regulated as securities markets and currency transactions are subject to settlement, custodial and other operational risks.

Convertible and Other Hybrid Securities Risk. Convertible and other hybrid securities (including preferred and convertible instruments) generally possess certain characteristics of both equity and debt securities. In addition to risks associated with investing in income securities, such as interest rate and credit risks, hybrid securities may be subject to issuer-specific and market risks generally applicable to equity securities. Convertible securities may also react to changes in the value of the common stock into which they convert, and are thus subject to equity investing and market risks. A convertible security may be converted at an inopportune time, which may decrease the Fund’s return.

Preferred Stock Risk. Although preferred stocks represent an ownership interest in an issuer, preferred stocks generally do not have voting rights or have limited voting rights and have economic characteristics similar to fixed-income securities. Preferred stocks are subject to issuer-specific risks generally applicable to equity securities and credit and interest rate risks generally applicable to fixed-income securities. The value of preferred stock generally declines when interest rates rise and may react more significantly than bonds and other debt instruments to actual or perceived changes in the company’s financial condition or prospects.

U.S. Government Securities Risk. Although certain U.S. Government-sponsored agencies (such as the Federal Home Loan Mortgage Corporation and the Federal National Mortgage Association) may be chartered or sponsored by acts of Congress, their securities are neither issued nor guaranteed by the U.S. Treasury. U.S. Treasury securities generally have a lower return than other obligations because of their higher credit quality and market liquidity.

Money Market Instrument Risk. Money market instruments may be adversely affected by market and economic events, such as a sharp rise in prevailing short-term interest rates; adverse developments in the banking industry, which issues or guarantees many money market instruments; adverse economic, political or other developments affecting issuers of money market instruments; changes in the credit quality of issuers; and default by a counterparty.

Derivatives Risk. The Fund’s exposure to derivatives involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other investments. The use of derivatives can lead to losses because of adverse movements in the price or value of the security, instrument, index, currency, commodity, economic indicator or event underlying a derivative (“reference instrument”), due to failure of a counterparty or due to tax or regulatory constraints. Derivatives may create leverage in the Fund, which represents a non-cash exposure to the underlying reference instrument. Leverage can increase both the risk and return potential of the Fund. Derivatives risk may be more significant when derivatives are used to enhance return or as a substitute for a cash investment position, rather than solely to hedge the risk of a position held by the Fund. Use of derivatives involves the exercise of specialized skill and judgment, and a transaction may be unsuccessful in whole or in part because of market behavior or unexpected events. Changes in the value of a derivative (including one used for hedging) may not correlate perfectly with the underlying

reference instrument. Derivative instruments traded in over-the-counter markets may be difficult to value, may be illiquid, and may be subject to wide swings in valuation caused by changes in the value of the underlying reference instrument. If a derivative’s counterparty is unable to honor its commitments, the value of Fund shares may decline and the Fund could experience delays in (or be unable to achieve) the return of collateral or other assets held by the counterparty. The loss on derivative transactions may substantially exceed the initial investment. A derivative investment also involves the risks relating to the reference instrument underlying the investment.

Liquidity Risk. The Fund is exposed to liquidity risk when trading volume, lack of a market maker or trading partner, large position size, market conditions, or legal restrictions impair its ability to sell particular investments or to sell them at advantageous market prices. Consequently, the Fund may have to accept a lower price to sell an investment or continue to hold it or keep the position open, sell other investments to raise cash or abandon an investment opportunity, any of which could have a negative effect on the Fund’s performance. These effects may be exacerbated during times of financial or political stress.

Risks Associated with Active Management. The success of the Fund’s investment strategy depends on portfolio management’s successful application of analytical skills and investment judgment. Active management involves subjective decisions and there is no guarantee that such decisions will produce the desired results or expected returns.

General Fund Investing Risks. The Fund is not a complete investment program and there is no guarantee that the Fund will achieve its investment objective. It is possible to lose money by investing in the Fund. The Fund is designed to be a long-term investment vehicle and is not suited for short-term trading. Investors in the Fund should have a long-term investment perspective and be able to tolerate potentially sharp declines in value. Purchase and redemption activities by Fund shareholders may impact the management of the Fund and its ability to achieve its investment objective(s). In addition, the redemption by one or more large shareholders or groups of shareholders of their holdings in the Fund could have an adverse impact on the remaining shareholders in the Fund. The Fund relies on various service providers, including the investment adviser and sub-adviser, if applicable, in its operations and is susceptible to operational, information security and related events (such as public health crises, cyber or hacking attacks) that may affect the service providers or the services that they provide to the Fund. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Risk Not Insured Depository Institution

rr_RiskNotInsuredDepositoryInstitution

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

Performance Narrative

rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and how the Fund’s average annual returns over time compare with those of a broad-based securities market index. The returns in the bar chart are for Class A shares and do not reflect a sales charge. If the sales charge was reflected, the returns would be lower. Past performance (both before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated Fund performance information can be obtained by visiting www.eatonvance.com.

Performance Availability Website Address

rr_PerformanceAvailabilityWebSiteAddress

www.eatonvance.com

Bar Chart Does Not Reflect Sales Loads

rr_BarChartDoesNotReflectSalesLoads

The returns in the bar chart are for Class A shares and do not reflect a sales charge. If the sales charge was reflected, the returns would be lower.

Bar Chart Closing

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For the ten years ended December 31, 2022, the highest quarterly total return for Class A was 8.59% for the quarter ended June 30, 2020, and the lowest quarterly return was -12.46% for the quarter ended March 31, 2020.

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the highest historical individual federal income tax rate and do not reflect the impact of state and local taxes. Actual after-tax returns depend on a shareholder’s tax situation and the actual characterization of distributions, and may differ from those shown.

Performance Table One Class of after Tax Shown

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax returns for other Classes of shares will vary from the after-tax returns presented for Class A shares.

Performance Table Footnotes, Reason Performance Information for Class Different from Immediately Preceding Period

rr_PerformanceTableFootnotesReasonPerformanceInformationForClassDifferentFromImmediatelyPrecedingPeriod

The Class R6 performance shown above for the period prior to June 27, 2016 (commencement of operations) is the performance of Class I shares at net asset value without adjustment for any differences in the expenses of the two classes. If adjusted for such differences, returns would be different.

Average Annual Return, Caption

rr_AverageAnnualReturnCaption

Average Annual Total Return as of December 31, 2022

Prospectus [Line Items]

rr_ProspectusLineItems

One Year

rr_AverageAnnualReturnYear01

(0.60%)

Ten Years

rr_AverageAnnualReturnYear10

3.67%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.53%

^[13]

1 Year

rr_ExpenseExampleYear01

$ 104

5 Years

rr_ExpenseExampleYear05

563

1 Year

rr_ExpenseExampleNoRedemptionYear01

104

5 Years

rr_ExpenseExampleNoRedemptionYear05

563

One Year

rr_AverageAnnualReturnYear01

(3.38%)

Ten Years

rr_AverageAnnualReturnYear10

3.02%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

^[14]

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.53%

^[13]

1 Year

rr_ExpenseExampleYear01

$ 426

5 Years

rr_ExpenseExampleYear05

870

1 Year

rr_ExpenseExampleNoRedemptionYear01

426

5 Years

rr_ExpenseExampleNoRedemptionYear05

870

2013

rr_AnnualReturn2013

5.02%

2015

rr_AnnualReturn2015

(1.80%)

2017

rr_AnnualReturn2017

4.34%

2019

rr_AnnualReturn2019

7.96%

2021

rr_AnnualReturn2021

4.41%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest quarterly total return

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

8.59%

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

One Year

rr_AverageAnnualReturnYear01

(6.49%)

Ten Years

rr_AverageAnnualReturnYear10

2.68%

Prospectus [Line Items]

rr_ProspectusLineItems

Five Years

rr_AverageAnnualReturnYear05

(0.17%)

One Year

rr_AverageAnnualReturnYear01

(3.84%)

Ten Years

rr_AverageAnnualReturnYear10

1.22%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

1.00%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.53%

^[13]

1 Year

rr_ExpenseExampleYear01

$ 280

5 Years

rr_ExpenseExampleYear05

959

1 Year

rr_ExpenseExampleNoRedemptionYear01

180

5 Years

rr_ExpenseExampleNoRedemptionYear05

959

One Year

rr_AverageAnnualReturnYear01

(5.05%)

Ten Years

rr_AverageAnnualReturnYear10

2.39%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.53%

^[13]

1 Year

rr_ExpenseExampleYear01

$ 79

5 Years

rr_ExpenseExampleYear05

428

1 Year

rr_ExpenseExampleNoRedemptionYear01

79

5 Years

rr_ExpenseExampleNoRedemptionYear05

428

One Year

rr_AverageAnnualReturnYear01

(3.14%)

Ten Years

rr_AverageAnnualReturnYear10

3.26%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.53%

^[13]

1 Year

rr_ExpenseExampleYear01

$ 73

5 Years

rr_ExpenseExampleYear05

395

1 Year

rr_ExpenseExampleNoRedemptionYear01

73

5 Years

rr_ExpenseExampleNoRedemptionYear05

395

One Year

rr_AverageAnnualReturnYear01

(3.08%)

Ten Years

rr_AverageAnnualReturnYear10

3.30%

Trading Symbol

dei_TradingSymbol

EEIAX

Prospectus [Line Items]

rr_ProspectusLineItems

Trading Symbol

dei_TradingSymbol

EEIIX

Prospectus [Line Items]

rr_ProspectusLineItems

Trading Symbol

dei_TradingSymbol

ECIMX

Prospectus [Line Items]

rr_ProspectusLineItems

Trading Symbol

dei_TradingSymbol

EGRAX

Prospectus [Line Items]

rr_ProspectusLineItems

Trading Symbol

dei_TradingSymbol

EGRIX

Prospectus [Line Items]

rr_ProspectusLineItems

Trading Symbol

dei_TradingSymbol

EGRSX

Prospectus [Line Items]

rr_ProspectusLineItems

Trading Symbol

dei_TradingSymbol

ECGMX

Prospectus [Line Items]

rr_ProspectusLineItems

Trading Symbol

dei_TradingSymbol

ERGMX

Prospectus [Line Items]

rr_ProspectusLineItems

Trading Symbol

dei_TradingSymbol

ETSIX

Prospectus [Line Items]

rr_ProspectusLineItems

Trading Symbol

dei_TradingSymbol

ESIIX

Prospectus [Line Items]

rr_ProspectusLineItems

Risk/Return

rr_RiskReturnHeading

Eaton Vance Global Bond Fund

Objective, Primary

rr_ObjectivePrimaryTextBlock

The Fund's investment objective is total return.

Expense Narrative

rr_ExpenseNarrativeTextBlock

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. Investors may also pay commissions or other fees to their financial intermediary, which are not reflected below. You may qualify for a reduced sales charge on purchases of Class A shares if you invest, or agree to invest over a 13-month period, at least $100,000 in Eaton Vance funds. Certain financial intermediaries also may offer variations in Fund sales charges to their customers as described in Appendix A – Financial Intermediary Sales Charge Variations in this Prospectus. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 75 of this Prospectus and page 27 of the Fund’s Statement of Additional Information.

Operating Expenses Caption

rr_OperatingExpensesCaption

Annual Fund Operating Expenses (expenses you pay each year as a percentage of the value of your investment)

^[15]

Portfolio Turnover

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

159.00%

Expense Breakpoint, Minimum Investment Required

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

$ 100,000

Expense Example Narrative

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 indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year, that the operating expenses remain the same and that any expense reimbursement arrangement remains in place for the contractual period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy Narrative

rr_StrategyNarrativeTextBlock

The Fund seeks its investment objective by investing in securities, derivatives and other instruments to establish investment exposures in both developed and emerging markets. Under normal market conditions, the Fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in bonds (the “80% Policy”). Bonds include fixed- and floating-rate debt instruments issued by U.S. and foreign companies, sovereign debt instruments, U.S. and foreign government debt instruments, commercial paper, securitized debt instruments (including commercial mortgage-backed securities, mortgage dollar rolls and collateralized mortgage obligations) and other asset-backed debt instruments (including collateralized debt obligations and stripped securities), zero-coupon securities, when-issued securities, repurchase agreements, obligations of supranational entities, municipal securities, structured notes, private placements, loans (including senior, subordinated, secured, and unsecured loans), convertible securities and other hybrid securities (including warrants) as well as derivatives that provide exposure to such investments. Total return is defined as income plus capital appreciation. The Fund normally invests at least 40% of its net assets in foreign investments. Foreign investments are those primarily traded outside the U.S. or issued by an issuer that is domiciled, or derives a significant portion of its revenue, outside the U.S.

The Fund’s investments may be significant in a geographic region. The Fund frequently has significant exposure to emerging markets investments. Emerging market countries include so-called frontier market countries, which generally are considered by the portfolio managers to be less developed countries that (i) are not included in the J.P. Morgan Government Bond Index: Emerging Markets (JPM GBI-EM) Global Diversified (Unhedged) (the “Index”); or (ii) represent 2% or less of the Index. The Fund normally invests at least 65% of its net assets in instruments rated investment grade (being those rated BBB or above by either S&P Global Ratings (“S&P”) or Fitch Ratings (“Fitch”), or Baa or higher by Moody’s Investors Service, Inc. (“Moody’s”)) or in unrated instruments considered to be of comparable quality by the investment adviser. The Fund also may invest in instruments rated below investment grade (rated below BBB by S&P or Fitch or Baa by Moody’s) or in unrated instruments considered to be of comparable quality by the investment adviser (often referred to as “junk” investments). The Fund may invest in investments of any duration. The Fund may invest up to 5% of net assets in equity securities.

The Fund invests in a wide variety of derivative instruments. The Fund expects to achieve certain exposures by purchasing and selling derivative instruments, including (but not limited to) forward foreign currency exchange contracts; futures on securities, indices, currencies, swaps and other investments; options; and interest rate swaps, cross-currency swaps, total return swaps and credit default swaps, which may create economic leverage in the Fund. The Fund may engage in derivative transactions to seek to enhance total return; to hedge against fluctuations in securities prices, interest rates or currency exchange rates; to change the effective duration of its portfolio; to manage certain investment risks; and/or as a substitute for the purchase or sale of securities or currencies. The Fund may use derivatives to implement various systematic investment processes, including taking long and short interest rate positions across various emerging markets to seek to enhance total return. The Fund’s use of derivatives may be extensive and, except as required by applicable regulation, there is no stated limit on their use.

In managing the Fund, the investment adviser adjusts investments in an effort to take advantage of differences in countries, currencies, interest rates and credits based on its global macroeconomic and political analysis. The investment adviser seeks to identify countries and currencies it believes have potential to outperform investments in other countries and currencies, and to anticipate changes in global economies, markets, political conditions and other factors for this purpose. The investment adviser considers the relative risk/return characteristics of prospective investments (whether securities, currencies, derivatives, or other instruments) in determining the most efficient means for achieving desired exposures. The portfolio managers may also consider financially material environmental, social and governance (“ESG”) factors in evaluating an issuer. These considerations may be taken into account alongside other fundamental research in the investment selection process.

The Fund invests its assets in the Portfolio, a separate registered investment company. The Portfolio is described in “Further Information about the Portfolio” in the Fund Prospectus.

Risk

rr_RiskHeading

Principal Risks

Risk Lose Money

rr_RiskLoseMoney

The Fund is not a complete investment program and there is no guarantee that the Fund will achieve its investment objective. It is possible to lose money by investing in the Fund.

Bar Chart and Performance Table

rr_BarChartAndPerformanceTableHeading

Performance

Performance Information Illustrates Variability of Returns

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and how the Fund’s average annual returns over time compare with those of a broad-based securities market index and a blended index.

Performance Past Does Not Indicate Future

rr_PerformancePastDoesNotIndicateFuture

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

Annual Return Caption

rr_AnnualReturnCaption

Calendar year-by-year total return

Performance Table Does Reflect Sales Loads

rr_PerformanceTableDoesReflectSalesLoads

These returns reflect the maximum current sales charge for to the Class A (3.25%) and any applicable contingent deferred sales charge (“CDSC”) for Class C.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

After-tax returns are not relevant to shareholders who hold shares in tax-deferred accounts or to shares held by non-taxable entities.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Return After Taxes on Distributions for a period may be the same as Return Before Taxes for that period because no taxable distributions were made during that period. Also, Return After Taxes on Distributions and the Sale of Fund Shares for a period may be greater than or equal to Return Before Taxes and/or Return After Taxes on Distributions for the same period because of losses realized on the sale of Fund shares.

Average Annual Return, Caption

rr_AverageAnnualReturnCaption

Average Annual Total Return as of December 31, 2022

Prospectus [Line Items]

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One Year

rr_AverageAnnualReturnYear01

(16.25%)

Ten Years

rr_AverageAnnualReturnYear10

(0.44%)

Prospectus [Line Items]

rr_ProspectusLineItems

One Year

rr_AverageAnnualReturnYear01

(15.80%)

^[16]

Ten Years

rr_AverageAnnualReturnYear10

(0.33%)

^[16]

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

^[17]

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.30%

Expenses Other than Interest Expense

rr_Component2OtherExpensesOverAssets

1.06%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.88%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.02%

3 Years

rr_ExpenseExampleYear03

816

10 Years

rr_ExpenseExampleYear10

2,387

3 Years

rr_ExpenseExampleNoRedemptionYear03

816

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 2,387

2014

rr_AnnualReturn2014

(0.51%)

2016

rr_AnnualReturn2016

2.16%

2018

rr_AnnualReturn2018

(2.67%)

2020

rr_AnnualReturn2020

9.32%

2022

rr_AnnualReturn2022

(11.29%)

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Dec. 31, 2022

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest quarterly return

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(8.12%)

Five Years

rr_AverageAnnualReturnYear05

(1.80%)

One Year

rr_AverageAnnualReturnYear01

(14.34%)

Ten Years

rr_AverageAnnualReturnYear10

(1.27%)

Prospectus [Line Items]

rr_ProspectusLineItems

Five Years

rr_AverageAnnualReturnYear05

(1.32%)

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.50%

Interest Expense

rr_Component1OtherExpensesOverAssets

0.02%

Other Expenses

rr_OtherExpensesOverAssets

1.08%

Expense Reimbursement (2)

rr_FeeWaiverOrReimbursementOverAssets

(0.86%)

^[18]

1 Year

rr_ExpenseExampleYear01

$ 275

5 Years

rr_ExpenseExampleYear05

1,293

1 Year

rr_ExpenseExampleNoRedemptionYear01

175

5 Years

rr_ExpenseExampleNoRedemptionYear05

1,293

One Year

rr_AverageAnnualReturnYear01

(12.75%)

Ten Years

rr_AverageAnnualReturnYear10

(0.62%)

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Expenses Other than Interest Expense

rr_Component2OtherExpensesOverAssets

1.06%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.58%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

0.72%

3 Years

rr_ExpenseExampleYear03

414

10 Years

rr_ExpenseExampleYear10

1,805

3 Years

rr_ExpenseExampleNoRedemptionYear03

414

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,805

Five Years

rr_AverageAnnualReturnYear05

(0.84%)

Risk/Return

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Eaton Vance Emerging Markets Local Income Fund

Objective, Primary

rr_ObjectivePrimaryTextBlock

The Fund's investment objective is total return.

Expense Narrative

rr_ExpenseNarrativeTextBlock

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. Investors may also pay commissions or other fees to their financial intermediary, which are not reflected below. You may qualify for a reduced sales charge on purchases of Class A shares if you invest, or agree to invest over a 13-month period, at least $100,000 in Eaton Vance funds. Certain financial intermediaries also may offer variations in Fund sales charges to their customers as described in Appendix A – Financial Intermediary Sales Charge Variations in this Prospectus. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 75 of this Prospectus and page 27 of the Fund’s Statement of Additional Information.

Operating Expenses Caption

rr_OperatingExpensesCaption

Annual Fund Operating Expenses (expenses you pay each year as a percentage of the value of your investment)

^[19]

Portfolio Turnover

rr_PortfolioTurnoverTextBlock

The Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” the 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 Portfolio's portfolio turnover rate was 33% of the average value of its portfolio.

Expense Breakpoint Discounts

rr_ExpenseBreakpointDiscounts

You may qualify for a reduced sales charge on purchases of Class A shares if you invest, or agree to invest over a 13-month period, at least $100,000 in Eaton Vance funds. Certain financial intermediaries also may offer variations in Fund sales charges to their customers as described in Appendix A – Financial Intermediary Sales Charge Variations in this Prospectus. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 75 of this Prospectus and page 27 of the Fund’s Statement of Additional Information.

Expense Example

rr_ExpenseExampleHeading

Example.

Strategy

rr_StrategyHeading

Principal Investment Strategies

Strategy Portfolio Concentration

rr_StrategyPortfolioConcentration

The Fund seeks its investment objective by investing in securities, derivatives and other instruments to establish investment exposures to emerging markets. Total return is defined as income plus capital appreciation. The Fund invests at least 80% of net assets (plus any borrowings for investment purposes) in (i) securities denominated in currencies of emerging market countries; (ii) fixed income instruments issued by emerging market entities or sovereign nations; and/or (iii) derivative instruments, denominated in or based on the currencies, interest rates, or issues of, emerging market countries (the “80% Policy”). Emerging market countries are defined to include any country that did not become a member of the Organization for Economic Cooperation and Development (O.E.C.D.) prior to 1975 and Turkey. Emerging market countries include so-called frontier market countries, which generally are considered by the portfolio managers to be less developed countries that (i) are not included in the J.P. Morgan Government Bond Index: Emerging Markets (JPM GBI-EM) Global Diversified (Unhedged) (the “Index”); or (ii) represent 2% or less of the Index. The Fund may have significant investment in a geographic region or country. The Fund has exposure to sovereign nations (including currencies, interest rates and debt instruments issued or guaranteed by sovereign entities) and duration. The Fund may invest in instruments of any credit rating, including those rated below investment grade (rated below BBB by either S&P Global Ratings or Fitch Ratings, or below Baa by Moody’s Investors Service, Inc.) or in unrated instruments considered to be of comparable quality by the investment adviser (often referred to as “junk” instruments). The Fund seeks to outperform the Index, however there can be no assurance that it will do so. The Fund is “non-diversified,” which means it may invest a greater percentage of its assets in the securities of a single issuer than a “diversified” fund.

Risk Narrative

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Market Risk. The value of investments held by the Fund may increase or decrease in response to social, economic, political, financial, public health crises or other disruptive events (whether real, expected or perceived) in the U.S. and global markets and include events such as war, natural disasters, epidemics and pandemics, terrorism, conflicts and social unrest. These events may negatively impact broad segments of businesses and populations and may exacerbate pre-existing risks to the Fund. The frequency and magnitude of resulting changes in the value of the Fund’s investments cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in reaction to changing market conditions. Monetary and/or fiscal actions taken by U.S. or foreign governments to stimulate or stabilize the global economy may not be effective and could lead to high market volatility. No active trading market may exist for certain investments held by the Fund, which may impair the ability of the Fund to sell or to realize the current valuation of such investments in the event of the need to liquidate such assets.

Foreign Investment Risk. Foreign investments can be adversely affected by political, economic and market developments abroad, including the imposition of economic and other sanctions by the United States or another country against a particular country or countries, organizations, entities and/or individuals. There may be less publicly available information about foreign issuers because they may not be subject to reporting practices, requirements or regulations comparable to those to which United States companies are subject. Adverse changes in investment regulations, capital requirements or exchange controls could adversely affect the value of the Fund's investments. Foreign markets may be smaller, less liquid and more volatile than the major markets in the United States and, as a result, Fund share values may be more volatile. Trading in foreign markets typically involves higher expense than trading in the United States. The Fund may have difficulties enforcing its legal or contractual rights in a foreign country.

Economic data as reported by sovereign entities may be delayed, inaccurate or fraudulent. In the event of a default by a sovereign entity, there are typically no assets to be seized or cash flows to be attached. Furthermore, the willingness or ability of a sovereign entity to restructure defaulted debt may be limited. Therefore, losses on sovereign defaults may far exceed the losses from the default of a similarly rated U.S. debt issuer.

Emerging Markets Investment Risk. Investment markets within emerging market countries are typically smaller, less liquid, less developed and more volatile than those in more developed markets like the United States, and may be focused in certain sectors. Emerging market securities often involve greater risks than developed market securities. The information available about an emerging market issuer may be less reliable than for comparable issuers in more developed capital markets. Such risks may be greater in frontier markets.

Frontier Market Investment Risk. Frontier markets are among the smallest and least mature investment markets. Frontier market countries may have greater political or economic instability and may also be subject to trade barriers, adjustments in currency values and developing or changing securities laws and other regulations. Investments in frontier market countries generally are less liquid and subject to greater price volatility than investments in developed markets or emerging markets.

Geographic Risk. Because the Fund may invest significantly in a particular geographic region or country, the value of Fund shares may be affected by events that adversely affect that region or country and may fluctuate more than that of a fund that invests more broadly.

Currency Risk. Exchange rates for currencies fluctuate daily. The value of foreign investments may be affected favorably or unfavorably by changes in currency exchange rates in relation to the U.S. dollar. Currency markets generally are not as regulated as securities markets and currency transactions are subject to settlement, custodial and other operational risks.

Credit Risk. Investments in fixed income and other debt obligations, including loans, (referred to below as “debt instruments”) are subject to the risk of non-payment of scheduled principal and interest. Changes in economic conditions or other circumstances may reduce the capacity of the party obligated to make principal and interest payments on such instruments and may lead to defaults. Such non-payments and defaults may reduce the value of Fund shares and income distributions. The value of debt instruments also may decline because of concerns about the issuer’s ability to make principal and interest payments. In addition, the credit ratings of debt instruments may be lowered if the financial condition of the party obligated to make payments with respect to such instruments deteriorates. In the event of bankruptcy of the issuer of a debt instrument, the Fund could experience delays or limitations with respect to its ability to realize the benefits of any collateral securing the instrument. In order to enforce its rights in the event of a default, bankruptcy or similar

situation, the Fund may be required to retain legal or similar counsel, which may increase the Fund’s operating expenses and adversely affect net asset value.

Interest Rate Risk. In general, the value of income securities will fluctuate based on changes in interest rates. The value of these securities is likely to increase when interest rates fall and decline when interest rates rise. Duration measures a fixed-income security’s price sensitivity to changes in the general level of interest rates. Generally, securities with longer durations or maturities are more sensitive to changes in interest rates than securities with shorter durations or maturities, causing them to be more volatile. Conversely, fixed-income securities with shorter durations or maturities will be less volatile but may provide lower returns than fixed-income securities with longer durations or maturities. In a rising interest rate environment, the duration of income securities that have the ability to be prepaid or called by the issuer may be extended. In a declining interest rate environment, the proceeds from prepaid or maturing instruments may have to be reinvested at a lower interest rate. Certain instruments held by the Fund pay an interest rate based on the London Interbank Offered Rate (“LIBOR”), which is the average offered rate for various maturities of short-term loans between certain major international banks. LIBOR is used throughout global banking and financial industries to determine interest rates for a variety of financial instruments (such as debt instruments and derivatives) and borrowing arrangements. The ICE Benchmark Administration Limited, the administrator of LIBOR, ceased publishing certain LIBOR settings on December 31, 2021, and is expected to cease publishing the remaining LIBOR settings on June 30, 2023. Although the transition process away from LIBOR has become increasingly well defined, the impact on certain debt securities, derivatives and other financial instruments that utilize LIBOR remains uncertain. The phase-out of LIBOR may result in, among other things, increased volatility or illiquidity in markets for instruments based on LIBOR and changes in the value of such instruments.

Lower Rated Investments Risk. Investments rated below investment grade and comparable unrated investments (sometimes referred to as “junk”) have speculative characteristics because of the credit risk associated with their issuers. Changes in economic conditions or other circumstances typically have a greater effect on the ability of issuers of lower rated investments to make principal and interest payments than they do on issuers of higher rated investments. An economic downturn generally leads to a higher non-payment rate, and a lower rated investment may lose significant value before a default occurs. Lower rated investments typically are subject to greater price volatility and illiquidity than higher rated investments.

Mortgage- and Asset-Backed Securities Risk. Mortgage- and asset-backed securities represent interests in “pools” of commercial or residential mortgages or other assets, including consumer loans or receivables. Movements in interest rates (both increases and decreases) may quickly and significantly reduce the value of certain types of mortgage- and asset-backed securities. Although certain mortgage- and asset-backed securities are guaranteed as to timely payment of interest and principal by a government entity, the market price for such securities is not guaranteed and will fluctuate. The purchase of mortgage- and asset-backed securities issued by non-government entities may entail greater risk than such securities that are issued or guaranteed by a government entity. Mortgage- and asset-backed securities issued by non-government entities may offer higher yields than those issued by government entities, but may also be subject to greater volatility than government issues and can also be subject to greater credit risk and the risk of default on the underlying mortgages or other assets. Investments in mortgage- and asset-backed securities are subject to both extension risk, where borrowers pay off their debt obligations more slowly in times of rising interest rates, and prepayment risk, where borrowers pay off their debt obligations sooner than expected in times of declining interest rates.

Stripped Securities Risk. Stripped Securities (“Strips”) are usually structured with classes that receive different proportions of the interest and principal distributions from an underlying asset or pool of underlying assets. Classes may receive only interest distributions (interest-only “IO”) or only principal (principal-only “PO”). Strips are particularly sensitive to changes in interest rates as such changes may increase or decrease prepayments of principal. A rapid or unexpected increase in prepayments can significantly depress the value of IO Strips, while a rapid or unexpected decrease can have the same effect on PO Strips.

Additional Risks of Loans. Loans are traded in a private, unregulated inter-dealer or inter-bank resale market and are generally subject to contractual restrictions that must be satisfied before a loan can be bought or sold. These restrictions may impede the Fund’s ability to buy or sell loans (thus affecting their liquidity) and may negatively impact the transaction price. See also “Market Risk” above. It also may take longer than seven days for transactions in loans to settle. Due to the possibility of an extended loan settlement process, the Fund may hold cash, sell investments or temporarily borrow from banks or other lenders to meet short-term liquidity needs, such as to satisfy redemption requests from Fund shareholders. The types of covenants included in loan agreements generally vary depending on market conditions, the creditworthiness of the issuer, the nature of the collateral securing the loan and possibly other factors. Loans with fewer covenants that restrict activities of the borrower may provide the borrower with more flexibility to take actions that may be detrimental to the loan holders and provide fewer investor protections in the event of such actions or if covenants are breached. The Fund may experience relatively greater realized or unrealized losses or delays and expense in enforcing its rights with

respect to loans with fewer restrictive covenants. Loans to entities located outside of the U.S. (including loans to sovereign entities) may have substantially different lender protections and covenants as compared to loans to U.S. entities and may involve greater risks. The Fund may have difficulties and incur expense enforcing its rights with respect to non-U.S. loans and such loans could be subject to bankruptcy laws that are materially different than in the U.S. Sovereign entities may be unable or unwilling to meet their obligations under a loan due to budgetary limitations or economic or political changes within the country. Loans may be structured such that they are not securities under securities law, and in the event of fraud or misrepresentation by a borrower, lenders may not have the protection of the anti-fraud provisions of the federal securities laws. Loans are also subject to risks associated with other types of income investments, including credit risk and risks of lower rated investments.

Municipal Obligations Risk. The amount of public information available about municipal obligations is generally less than for corporate equities or bonds, meaning that the investment performance of municipal obligations may be more dependent on the analytical abilities of the investment adviser than stock or corporate bond investments. The secondary market for municipal obligations also tends to be less well-developed and less liquid than many other securities markets, which may limit the Fund’s ability to sell its municipal obligations at attractive prices. The differences between the price at which an obligation can be purchased and the price at which it can be sold may widen during periods of market distress. Less liquid obligations can become more difficult to value and be subject to erratic price movements. The increased presence of non-traditional participants (such as proprietary trading desks of investment banks and hedge funds) or the absence of traditional participants (such as individuals, insurance companies, banks and life insurance companies) in the municipal markets may lead to greater volatility in the markets because non-traditional participants may trade more frequently or in greater volume.

Commodity-Related Investments Risk. The value of commodity investments will generally be affected by overall market movements and factors specific to a particular industry or commodity, which may include weather, embargoes, tariffs, and health, political, international and regulatory developments. Economic and other events (whether real or perceived) can reduce the demand for commodities, which may reduce market prices and cause the value of the Fund’s commodity investments to fall. The frequency and magnitude of such changes are unpredictable. Exposure to commodities and commodity markets may subject the Fund to greater volatility than investments in traditional securities. No active trading market may exist for certain commodity investments, which may impair the ability of the Fund to sell or to realize the full value of such investments in the event of the need to liquidate such investments. In addition, adverse market conditions may impair the liquidity of actively traded commodity investments.

Derivatives Risk. The Fund’s exposure to derivatives involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other investments. The use of derivatives can lead to losses because of adverse movements in the price or value of the security, instrument, index, currency, commodity, economic indicator or event underlying a derivative (“reference instrument”), due to failure of a counterparty or due to tax or regulatory constraints. Derivatives may create leverage in the Fund, which represents a non-cash exposure to the underlying reference instrument. Leverage can increase both the risk and return potential of the Fund. Derivatives risk may be more significant when derivatives are used to enhance return or as a substitute for a cash investment position, rather than solely to hedge the risk of a position held by the Fund. Use of derivatives involves the exercise of specialized skill and judgment, and a transaction may be unsuccessful in whole or in part because of market behavior or unexpected events. Changes in the value of a derivative (including one used for hedging) may not correlate perfectly with the underlying reference instrument. Derivative instruments traded in over-the-counter markets may be difficult to value, may be illiquid, and may be subject to wide swings in valuation caused by changes in the value of the underlying reference instrument. If a derivative’s counterparty is unable to honor its commitments, the value of Fund shares may decline and the Fund could experience delays in (or be unable to achieve) the return of collateral or other assets held by the counterparty. The loss on derivative transactions may substantially exceed the initial investment. A derivative investment also involves the risks relating to the reference instrument underlying the investment.

Leverage Risk. Certain Fund transactions may give rise to leverage. Leverage can result from a non-cash exposure to an underlying reference instrument. Leverage can increase both the risk and return potential of the Fund. The use of leverage may cause the Fund to maintain liquid assets or liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet segregation requirements. Leverage may cause the Fund’s share price to be more volatile than if it had not been leveraged, as certain types of leverage may exaggerate the effect of any increase or decrease in the value of the Fund’s portfolio securities. The loss on leveraged investments may substantially exceed the initial investment.

Restricted Securities Risk. Unless registered for sale to the public under applicable federal securities law, restricted securities can be sold only in private transactions to qualified purchasers pursuant to an exemption from registration. The sale price realized from a private transaction could be less than the Fund’s purchase price for the restricted security. It

may be difficult to identify a qualified purchaser for a restricted security held by the Fund and such security could be deemed illiquid. It may also be more difficult to value such securities.

Liquidity Risk. The Fund is exposed to liquidity risk when trading volume, lack of a market maker or trading partner, large position size, market conditions, or legal restrictions impair its ability to sell particular investments or to sell them at advantageous market prices. Consequently, the Fund may have to accept a lower price to sell an investment or continue to hold it or keep the position open, sell other investments to raise cash or abandon an investment opportunity, any of which could have a negative effect on the Fund’s performance. These effects may be exacerbated during times of financial or political stress.

Convertible and Other Hybrid Securities Risk. Convertible and other hybrid securities (including preferred and convertible instruments) generally possess certain characteristics of both equity and debt securities. In addition to risks associated with investing in income securities, such as interest rate and credit risks, hybrid securities may be subject to issuer-specific and market risks generally applicable to equity securities. Convertible securities may also react to changes in the value of the common stock into which they convert, and are thus subject to equity investing and market risks. A convertible security may be converted at an inopportune time, which may decrease the Fund’s return.

When-Issued and Forward Commitment Risk. Securities purchased on a when-issued or forward commitment basis are subject to the risk that when delivered they will be worth less than the agreed upon payment price.

Short Sale Risk. The Fund will incur a loss as a result of a short sale if the price of the security sold short increases in value between the date of the short sale and the date on which the Fund purchases the security to replace the borrowed security. Short sale risks include, among others, the potential loss of more money than the actual cost of the investment, and the risk that the third party to the short sale may fail to honor its contract terms, causing a loss to the Fund.

Equity Securities Risk. The value of equity securities and related instruments may decline in response to adverse changes in the economy or the economic outlook; deterioration in investor sentiment; interest rate, currency, and commodity price fluctuations; adverse geopolitical, social or environmental developments; issuer and sector-specific considerations; unexpected trading activity among retail investors; or other factors. Market conditions may affect certain types of stocks to a greater extent than other types of stocks. If the stock market declines in value, the value of the Fund’s equity securities will also likely decline. Although prices can rebound, there is no assurance that values will return to previous levels.

U.S. Government Securities Risk. Although certain U.S. Government-sponsored agencies (such as the Federal Home Loan Mortgage Corporation and the Federal National Mortgage Association) may be chartered or sponsored by acts of Congress, their securities are neither issued nor guaranteed by the U.S. Treasury. U.S. Treasury securities generally have a lower return than other obligations because of their higher credit quality and market liquidity.

Risks of Repurchase Agreements and Reverse Repurchase Agreements. In the event of the insolvency of the counterparty to a repurchase agreement or reverse repurchase agreement, recovery of the repurchase price owed to the Fund or, in the case of a reverse repurchase agreement, the securities sold by the Fund, may be delayed. In a repurchase agreement, such insolvency may result in a loss to the extent that the value of the purchased securities decreases during the delay or that value has otherwise not been maintained at an amount equal to the repurchase price. In a reverse repurchase agreement, the counterparty’s insolvency may result in a loss equal to the amount by which the value of the securities sold by the Fund exceeds the repurchase price payable by the Fund; if the value of the purchased securities increases during such a delay, that loss may also be increased. When the Fund enters into a reverse repurchase agreement, any fluctuations in the market value of either the securities sold to the counterparty or the securities which the Fund purchases with its proceeds from the agreement would affect the value of the Fund’s assets. As a result, such agreements may increase fluctuations in the net asset value of the Fund’s shares. Because reverse repurchase agreements may be considered to be a form of borrowing by the Fund (and a loan from the counterparty), they create leverage. If the Fund reinvests the proceeds of a reverse repurchase agreement at a rate lower than the cost of the agreement, entering into the agreement will lower the Fund’s yield.

Issuer Non-Diversification Risk. The Fund is “non-diversified,” which means it may invest a greater percentage of its assets in the securities of a single issuer than a fund that is “diversified.” Non-diversified funds may focus their investments in a small number of issuers, making them more susceptible to risks affecting such issuers than a more diversified fund might be, and the value of the Fund's shares may be more volatile than the values of shares of more diversified funds.

Investing in a Portfolio. The Fund invests its assets in the Portfolio. This enables the Fund to pool its assets with other investors that also invest in the same Portfolio, resulting in efficiencies in management and administration that can lower the Fund’s costs and enhance shareholder returns. The ability of the Fund operating in a hub and spoke structure to meet its investment objective is directly related to the ability of the corresponding Portfolio to meet its objective. Contribution

and withdrawal activities by other Portfolio investors may impact the management of the Portfolio and its ability to achieve its investment objective.

Management Risk. The success of the Fund's investment strategy depends on portfolio management's successful application of analytical skills and investment judgment. Active management involves subjective decisions. The Fund may utilize systematic investment processes to seek to take advantage of certain quantitative and behavioral market characteristics identified by the investment adviser. A systematic investment process is dependent on the investment adviser's skill in developing and maintaining that process.

General Fund Investing Risks. The Fund is not a complete investment program and there is no guarantee that the Fund will achieve its investment objective. It is possible to lose money by investing in the Fund. The Fund is designed to be a long-term investment vehicle and is not suited for short-term trading. Investors in the Fund should have a long-term investment perspective and be able to tolerate potentially sharp declines in value. Purchase and redemption activities by Fund shareholders may impact the management of the Fund and its ability to achieve its investment objective(s). In addition, the redemption by one or more large shareholders or groups of shareholders of their holdings in the Fund could have an adverse impact on the remaining shareholders in the Fund. The Fund relies on various service providers, including the investment adviser and sub-adviser, if applicable, in its operations and is susceptible to operational, information security and related events (such as public health crises, cyber or hacking attacks) that may affect the service providers or the services that they provide to the Fund. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Risk Not Insured Depository Institution

rr_RiskNotInsuredDepositoryInstitution

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

Bar Chart and Performance Table

rr_BarChartAndPerformanceTableHeading

Performance

Performance Information Illustrates Variability of Returns

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and how the Fund’s average annual returns over time compare with those of a broad-based securities market index.

Performance Past Does Not Indicate Future

rr_PerformancePastDoesNotIndicateFuture

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

Annual Return Caption

rr_AnnualReturnCaption

Calendar year-by-year total return

Performance Table Does Reflect Sales Loads

rr_PerformanceTableDoesReflectSalesLoads

These returns reflect the maximum current sales charge for to the Class A (3.25%) and any applicable contingent deferred sales charge (“CDSC”) for Class C.

Performance Table Not Relevant to Tax Deferred

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After-tax returns are not relevant to shareholders who hold shares in tax-deferred accounts or to shares held by non-taxable entities.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Return After Taxes on Distributions for a period may be the same as Return Before Taxes for that period because no taxable distributions were made during that period. Also, Return After Taxes on Distributions and the Sale of Fund Shares for a period may be greater than or equal to Return Before Taxes and/or Return After Taxes on Distributions for the same period because of losses realized on the sale of Fund shares.

Average Annual Return, Caption

rr_AverageAnnualReturnCaption

Average Annual Total Return as of December 31, 2022

Prospectus [Line Items]

rr_ProspectusLineItems

One Year

rr_AverageAnnualReturnYear01

(11.69%)

Ten Years

rr_AverageAnnualReturnYear10

(2.03%)

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

^[20]

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.30%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.19%

3 Years

rr_ExpenseExampleYear03

691

10 Years

rr_ExpenseExampleYear10

1,721

3 Years

rr_ExpenseExampleNoRedemptionYear03

691

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,721

2014

rr_AnnualReturn2014

(4.04%)

2016

rr_AnnualReturn2016

12.33%

2018

rr_AnnualReturn2018

(8.40%)

2020

rr_AnnualReturn2020

4.67%

2022

rr_AnnualReturn2022

(11.98%)

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2020

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest quarterly return

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(16.32%)

Five Years

rr_AverageAnnualReturnYear05

(1.53%)

One Year

rr_AverageAnnualReturnYear01

(15.42%)

Ten Years

rr_AverageAnnualReturnYear10

(1.99%)

Prospectus [Line Items]

rr_ProspectusLineItems

Five Years

rr_AverageAnnualReturnYear05

(0.28%)

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.65%

Other Expenses

rr_OtherExpensesOverAssets

0.24%

1 Year

rr_ExpenseExampleYear01

$ 292

5 Years

rr_ExpenseExampleYear05

1,021

1 Year

rr_ExpenseExampleNoRedemptionYear01

192

5 Years

rr_ExpenseExampleNoRedemptionYear05

1,021

One Year

rr_AverageAnnualReturnYear01

(13.33%)

Ten Years

rr_AverageAnnualReturnYear10

(1.17%)

Prospectus [Line Items]

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Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.89%

3 Years

rr_ExpenseExampleYear03

284

10 Years

rr_ExpenseExampleYear10

1,096

3 Years

rr_ExpenseExampleNoRedemptionYear03

284

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,096

Five Years

rr_AverageAnnualReturnYear05

(0.60%)

Risk/Return

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Eaton Vance Global Macro Absolute Return Fund

Objective, Primary

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The Fund's investment objective is total return.

Expense Narrative

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This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. Investors may also pay commissions or other fees to their financial intermediary, which are not reflected below. You may qualify for a reduced sales charge on purchases of Class A shares if you invest, or agree to invest over a 13-month period, at least $100,000 in Eaton Vance funds. Certain financial intermediaries also may offer variations in Fund sales charges to their customers as described in Appendix A – Financial Intermediary Sales Charge Variations in this Prospectus. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 75 of this Prospectus and page 27 of the Fund’s Statement of Additional Information.

Operating Expenses Caption

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Annual Fund Operating Expenses (expenses you pay each year as a percentage of the value of your investment)

^[21]

Portfolio Turnover

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The Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” the 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 Portfolio's portfolio turnover rate was 81% of the average value of its portfolio.

Expense Breakpoint Discounts

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You may qualify for a reduced sales charge on purchases of Class A shares if you invest, or agree to invest over a 13-month period, at least $100,000 in Eaton Vance funds. Certain financial intermediaries also may offer variations in Fund sales charges to their customers as described in Appendix A – Financial Intermediary Sales Charge Variations in this Prospectus. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 75 of this Prospectus and page 27 of the Fund’s Statement of Additional Information.

Expense Example

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Example.

Strategy

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Principal Investment Strategies

Strategy Portfolio Concentration

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The Fund seeks its investment objective by investing in securities, derivatives and other instruments to establish long and short investment exposures around the world. Total return is defined as income plus capital appreciation. The Fund normally invests in multiple countries (at least three different countries, one of which can be the United States) and frequently has significant exposure to foreign currencies and investments. The Fund’s long and short investments are primarily sovereign exposures, including currencies, interest rates and debt instruments issued or guaranteed by sovereign entities (including U.S. Treasuries). The Fund may invest in instruments of any credit rating, including those rated below investment grade (rated below BBB by either S&P Global Ratings or Fitch Ratings, or below Baa by Moody’s Investors Service, Inc.) or in unrated instruments considered to be of comparable quality by the investment adviser (often referred to as “junk” instruments). The Fund may have significant investment in a geographic region or country, typically including less-developed countries. Less-developed countries are commonly referred to as emerging market countries, which include so-called frontier market countries. Frontier countries generally are considered by the portfolio managers to be less developed countries that (i) are not included in the J.P. Morgan Government Bond Index: Emerging Markets (JPM GBI-EM) Global Diversified (Unhedged) (the “Index”); or (ii) represent 2% or less of the Index. Normally, not more than 25% of the Fund’s assets are invested in securities or issuers in any one foreign country or denominated in any one currency other than the U.S. dollar or the euro. The Fund is “non-diversified,” which means it may invest a greater percentage of its assets in the securities of a single issuer than a “diversified” fund.

Risk Narrative

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Market Risk. The value of investments held by the Fund may increase or decrease in response to social, economic, political, financial, public health crises or other disruptive events (whether real, expected or perceived) in the U.S. and global markets and include events such as war, natural disasters, epidemics and pandemics, terrorism, conflicts and social unrest. These events may negatively impact broad segments of businesses and populations and may exacerbate pre-existing risks to the Fund. The frequency and magnitude of resulting changes in the value of the Fund’s investments cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in reaction to changing market conditions. Monetary and/or fiscal actions taken by U.S. or foreign governments to stimulate or stabilize the global economy may not be effective and could lead to high market volatility. No active trading market may exist for certain investments held by the Fund, which may impair the ability of the Fund to sell or to realize the current valuation of such investments in the event of the need to liquidate such assets.

Absolute Return Strategy. The Fund employs an “absolute return” investment approach. A fund that employs an absolute return strategy typically benchmarks itself to an index of cash instruments and seeks to achieve returns that are largely independent of broad movements in stocks and bonds. Unlike equity funds, such funds should not be expected to benefit from general equity market returns. Different from fixed income funds, such funds may not generate current income and should not be expected to experience price appreciation as interest rates decline. Although the Fund’s investment adviser seeks to maximize absolute return, the Fund may not generate positive returns and may suffer losses.

Foreign Investment Risk. Foreign investments can be adversely affected by political, economic and market developments abroad, including the imposition of economic and other sanctions by the United States or another country against a particular country or countries, organizations, entities and/or individuals. There may be less publicly available information about foreign issuers because they may not be subject to reporting practices, requirements or regulations comparable to those to which United States companies are subject. Adverse changes in investment regulations, capital requirements or exchange controls could adversely affect the value of the Fund's investments. Foreign markets may be smaller, less liquid and more volatile than the major markets in the United States and, as a result, Fund share values may be more volatile. Trading in foreign markets typically involves higher expense than trading in the United States. The Fund may have difficulties enforcing its legal or contractual rights in a foreign country.

Economic data as reported by sovereign entities may be delayed, inaccurate or fraudulent. In the event of a default by a sovereign entity, there are typically no assets to be seized or cash flows to be attached. Furthermore, the willingness or ability of a sovereign entity to restructure defaulted debt may be limited. Therefore, losses on sovereign defaults may far exceed the losses from the default of a similarly rated U.S. debt issuer.

Emerging Markets Investment Risk. Investment markets within emerging market countries are typically smaller, less liquid, less developed and more volatile than those in more developed markets like the United States, and may be focused in certain sectors. Emerging market securities often involve greater risks than developed market securities. The information available about an emerging market issuer may be less reliable than for comparable issuers in more developed capital markets. Such risks may be greater in frontier markets.

Frontier Market Investment Risk. Frontier markets are among the smallest and least mature investment markets. Frontier market countries may have greater political or economic instability and may also be subject to trade barriers, adjustments in currency values and developing or changing securities laws and other regulations. Investments in frontier market countries generally are less liquid and subject to greater price volatility than investments in developed markets or emerging markets.

Currency Risk. Exchange rates for currencies fluctuate daily. The value of foreign investments may be affected favorably or unfavorably by changes in currency exchange rates in relation to the U.S. dollar. Currency markets generally are not as regulated as securities markets and currency transactions are subject to settlement, custodial and other operational risks.

Credit Risk. Investments in fixed income and other debt obligations, including loans, (referred to below as “debt instruments”) are subject to the risk of non-payment of scheduled principal and interest. Changes in economic conditions or other circumstances may reduce the capacity of the party obligated to make principal and interest payments on such instruments and may lead to defaults. Such non-payments and defaults may reduce the value of Fund shares and income distributions. The value of debt instruments also may decline because of concerns about the issuer’s ability to make principal and interest payments. In addition, the credit ratings of debt instruments may be lowered if the financial condition of the party obligated to make payments with respect to such instruments deteriorates. In the event of bankruptcy of the issuer of a debt instrument, the Fund could experience delays or limitations with respect to its ability to realize the benefits of any collateral securing the instrument. In order to enforce its rights in the event of a default, bankruptcy or similar situation, the Fund may be required to retain legal or similar counsel, which may increase the Fund’s operating expenses and adversely affect net asset value.

Interest Rate Risk. In general, the value of income securities will fluctuate based on changes in interest rates. The value of these securities is likely to increase when interest rates fall and decline when interest rates rise. Duration measures a fixed-income security’s price sensitivity to changes in the general level of interest rates. Generally, securities with longer durations or maturities are more sensitive to changes in interest rates than securities with shorter durations or maturities, causing them to be more volatile. Conversely, fixed-income securities with shorter durations or maturities will be less volatile but may provide lower returns than fixed-income securities with longer durations or maturities. The impact of interest rate changes is significantly less for floating-rate investments that have relatively short periodic rate resets (e.g., ninety days or less). In a rising interest rate environment, the duration of income securities that have the ability to be prepaid or called by the issuer may be extended. In a declining interest rate environment, the proceeds from prepaid or maturing instruments may have to be reinvested at a lower interest rate.

LIBOR Risk. The London Interbank Offered Rate or LIBOR is used throughout global banking and financial industries to determine interest rates for a variety of financial instruments (such as debt instruments and derivatives) and borrowing arrangements. The ICE Benchmark Administration Limited, the administrator of LIBOR, ceased publishing certain LIBOR settings on December 31, 2021, and is expected to cease publishing the remaining LIBOR settings on June 30, 2023. The Fund has exposure to LIBOR-based instruments. Although the transition process away from LIBOR has become increasingly well defined, the impact on certain debt securities, derivatives and other financial instruments that utilize LIBOR remains uncertain. The transition process may involve, among other things, increased volatility or illiquidity in markets for instruments that currently rely on LIBOR, such as floating-rate debt obligations. Any effects of the transition away from LIBOR and the adoption of alternative reference rates, as well as other unforeseen effects, could result in losses to the Fund, and such effects may occur prior to the anticipated discontinuation of the remaining LIBOR settings in 2023. Furthermore, the risks associated with the discontinuation of LIBOR and transition to replacement rates may be exacerbated if an orderly transition to an alternative reference rate is not completed in a timely manner.

Lower Rated Investments Risk. Investments rated below investment grade and comparable unrated investments (sometimes referred to as “junk”) have speculative characteristics because of the credit risk associated with their issuers. Changes in economic conditions or other circumstances typically have a greater effect on the ability of issuers of lower rated investments to make principal and interest payments than they do on issuers of higher rated investments. An economic downturn generally leads to a higher non-payment rate, and a lower rated investment may lose significant value before a default occurs. Lower rated investments typically are subject to greater price volatility and illiquidity than higher rated investments.

Mortgage- and Asset-Backed Securities Risk. Mortgage- and asset-backed securities represent interests in “pools” of commercial or residential mortgages or other assets, including consumer loans or receivables. Movements in interest rates (both increases and decreases) may quickly and significantly reduce the value of certain types of mortgage- and asset-backed securities. Although certain mortgage- and asset-backed securities are guaranteed as to timely payment of interest and principal by a government entity, the market price for such securities is not guaranteed and will fluctuate. The purchase of mortgage- and asset-backed securities issued by non-government entities may entail greater risk than such securities that are issued or guaranteed by a government entity. Mortgage- and asset-backed securities issued by non-government entities may offer higher yields than those issued by government entities, but may also be subject to greater volatility than government issues and can also be subject to greater credit risk and the risk of default on the underlying mortgages or other assets. Investments in mortgage- and asset-backed securities are subject to both extension risk, where borrowers pay off their debt obligations more slowly in times of rising interest rates, and prepayment risk, where borrowers pay off their debt obligations sooner than expected in times of declining interest rates.

Stripped Securities Risk. Stripped Securities (“Strips”) are usually structured with classes that receive different proportions of the interest and principal distributions from an underlying asset or pool of underlying assets. Classes may receive only interest distributions (interest-only “IO”) or only principal (principal-only “PO”). Strips are particularly sensitive to changes in interest rates as such changes may increase or decrease prepayments of principal. A rapid or unexpected increase in prepayments can significantly depress the value of IO Strips, while a rapid or unexpected decrease can have the same effect on PO Strips.

Additional Risks of Loans. Loans are traded in a private, unregulated inter-dealer or inter-bank resale market and are generally subject to contractual restrictions that must be satisfied before a loan can be bought or sold. These restrictions may impede the Fund’s ability to buy or sell loans (thus affecting their liquidity) and may negatively impact the transaction price. See also “Market Risk” above. It also may take longer than seven days for transactions in loans to settle. Due to the possibility of an extended loan settlement process, the Fund may hold cash, sell investments or temporarily borrow from banks or other lenders to meet short-term liquidity needs, such as to satisfy redemption requests from Fund shareholders. The types of covenants included in loan agreements generally vary depending on market conditions, the creditworthiness of the issuer, the nature of the collateral securing the loan and possibly other factors. Loans with fewer covenants that restrict activities of the borrower may provide the borrower with more flexibility to take actions that may be detrimental to the loan holders and provide fewer investor protections in the event of such actions or if covenants are breached. The Fund may experience relatively greater realized or unrealized losses or delays and expense in enforcing its rights with respect to loans with fewer restrictive covenants. Loans to entities located outside of the U.S. (including loans to sovereign entities) may have substantially different lender protections and covenants as compared to loans to U.S. entities and may involve greater risks. The Fund may have difficulties and incur expense enforcing its rights with respect to non-U.S. loans and such loans could be subject to bankruptcy laws that are materially different than in the U.S. Sovereign entities may be unable or unwilling to meet their obligations under a loan due to budgetary limitations or economic or political changes within the country. Loans may be structured such that they are not securities under securities law, and in the event of fraud or misrepresentation by a borrower, lenders may not have the protection of the anti-fraud provisions of the federal securities laws. Loans are also subject to risks associated with other types of income investments, including credit risk and risks of lower rated investments.

Derivatives Risk. The Fund’s exposure to derivatives involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other investments. The use of derivatives can lead to losses because of adverse movements in the price or value of the security, instrument, index, currency, commodity, economic indicator or event underlying a derivative (“reference instrument”), due to failure of a counterparty or due to tax or regulatory constraints. Derivatives may create leverage in the Fund, which represents a non-cash exposure to the underlying reference instrument. Leverage can increase both the risk and return potential of the Fund. Derivatives risk may be more significant when derivatives are used to enhance return or as a substitute for a cash investment position, rather than solely to hedge the risk of a position held by the Fund. Use of derivatives involves the exercise of specialized skill and judgment, and a transaction may be unsuccessful in whole or in part because of market behavior or unexpected events. Changes in the value of a derivative (including one used for hedging) may not correlate perfectly with the underlying reference instrument. Derivative instruments traded in over-the-counter markets may be difficult to value, may be illiquid, and may be subject to wide swings in valuation caused by changes in the value of the underlying reference instrument. If a derivative’s counterparty is unable to honor its commitments, the value of Fund shares may decline and the Fund could experience delays in (or be unable to achieve) the return of collateral or other assets held by the counterparty. The loss on derivative transactions may substantially exceed the initial investment. A derivative investment also involves the risks relating to the reference instrument underlying the investment.

Leverage Risk. Certain Fund transactions may give rise to leverage. Leverage can result from a non-cash exposure to an underlying reference instrument. Leverage can increase both the risk and return potential of the Fund. The use of leverage may cause the Fund to maintain liquid assets or liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet segregation requirements. Leverage may cause the Fund’s share price to be more volatile than if it had not been leveraged, as certain types of leverage may exaggerate the effect of any increase or decrease in the value of the Fund’s portfolio securities. The loss on leveraged investments may substantially exceed the initial investment.

Commodity-Related Investments Risk. The value of commodity investments will generally be affected by overall market movements and factors specific to a particular industry or commodity, which may include weather, embargoes, tariffs, and health, political, international and regulatory developments. Economic and other events (whether real or perceived) can reduce the demand for commodities, which may reduce market prices and cause the value of the Fund’s commodity investments to fall. The frequency and magnitude of such changes are unpredictable. Exposure to commodities and commodity markets may subject the Fund to greater volatility than investments in traditional securities. No active trading market may exist for certain commodity investments, which may impair the ability of the Fund to sell or to realize the full

value of such investments in the event of the need to liquidate such investments. In addition, adverse market conditions may impair the liquidity of actively traded commodity investments. Commodity-linked notes may be structured such that their performance deviates significantly from the underlying index or instrument.

As noted above, the Fund expects to invest in the Subsidiary, which invests in commodity-related investments, as well as other permitted instruments. The Subsidiary is subject to the laws of the Cayman Islands and is not subject to U.S. laws, including securities laws and their protections and provisions of the Internal Revenue Code (the “Code”). Because the Subsidiary is not registered under U.S. federal securities laws, it may not be able to negotiate terms with its counterparties that are equivalent to those of a registered fund. As a result, the Subsidiary may have greater exposure to those counterparties than a registered fund. Changes in the laws of the United States and/or the Cayman Islands could result in the inability of the Subsidiary to operate as described, and could adversely affect the Fund’s investment approach. In addition, commodity-related investments generally generate income that is not qualifying income for purposes of meeting source of income tests applicable to mutual funds under the Code. The Internal Revenue Service (“IRS”) has issued proposed regulations effectively providing that the Subsidiary’s realized annual net profit, if any, will constitute “qualifying income” only to the extent it is timely and currently repatriated to the Portfolio (notwithstanding any previously issued private letter ruling or advice from counsel). As the Fund intends to satisfy the source of income tests under the Code, its ability to invest in commodity-related investments may become limited, and the Fund may incur transaction and other costs to comply with any new or additional guidance from the IRS. The tax treatment of commodity-related investments and income from the Subsidiary may be adversely affected by future legislation, Treasury Regulations and/or guidance issued by the IRS that could affect the character, timing and/or amount of the Fund’s taxable income or any gains and distributions made by the Fund.

Municipal Obligations Risk. The amount of public information available about municipal obligations is generally less than for corporate equities or bonds, meaning that the investment performance of municipal obligations may be more dependent on the analytical abilities of the investment adviser than stock or corporate bond investments. The secondary market for municipal obligations also tends to be less well-developed and less liquid than many other securities markets, which may limit the Fund’s ability to sell its municipal obligations at attractive prices. The differences between the price at which an obligation can be purchased and the price at which it can be sold may widen during periods of market distress. Less liquid obligations can become more difficult to value and be subject to erratic price movements. The increased presence of non-traditional participants (such as proprietary trading desks of investment banks and hedge funds) or the absence of traditional participants (such as individuals, insurance companies, banks and life insurance companies) in the municipal markets may lead to greater volatility in the markets because non-traditional participants may trade more frequently or in greater volume.

Convertible and Other Hybrid Securities Risk. Convertible and other hybrid securities (including preferred and convertible instruments) generally possess certain characteristics of both equity and debt securities. In addition to risks associated with investing in income securities, such as interest rate and credit risks, hybrid securities may be subject to issuer-specific and market risks generally applicable to equity securities. Convertible securities may also react to changes in the value of the common stock into which they convert, and are thus subject to equity investing and market risks. A convertible security may be converted at an inopportune time, which may decrease the Fund’s return.

Restricted Securities Risk. Unless registered for sale to the public under applicable federal securities law, restricted securities can be sold only in private transactions to qualified purchasers pursuant to an exemption from registration. The sale price realized from a private transaction could be less than the Fund’s purchase price for the restricted security. It may be difficult to identify a qualified purchaser for a restricted security held by the Fund and such security could be deemed illiquid. It may also be more difficult to value such securities.