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dei_DocumentPeriodEndDate

Sep. 30, 2021

Entity Central Index Key

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0001593547

Amendment Flag

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false

Document Effective Date

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Sep. 30, 2022

Risk/Return [Heading]

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Mesirow Enhanced Core Plus Fund

Objective, Primary [Text Block]

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The Mesirow Enhanced Core Plus Fund (the “Enhanced Core Plus Fund” or the “Fund”) seeks to maximize total return through capital appreciation and current income consistent with preservation of capital.

Expense Narrative [Text Block]

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This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Operating Expenses Caption [Text]

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

Portfolio Turnover [Heading]

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Portfolio Turnover

Portfolio Turnover, Rate

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72.00%

Expense Example Narrative [Text Block]

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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 and that the Fund’s operating expenses (including one year of capped expenses in each period) remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy Narrative [Text Block]

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Under normal circumstances, the Fund invests at least 80% of its net assets, plus any borrowings for investment purposes, in fixed income securities and other financial instruments with economic characteristics similar to such securities. The Fund primarily invests

in investment-grade fixed income securities with an adjusted portfolio duration that normally varies within two years (plus or minus) of the adjusted duration of the securities comprising the Bloomberg U.S. Aggregate Index. As of September 30, 2021, the average portfolio duration of securities comprising the Bloomberg U.S. Aggregate Index was approximately 6.6 years. Duration is a measure of the expected life of a fixed income security that is used to determine the sensitivity of a security’s price to changes in interest rates.

For purposes of the Fund’s 80% investment policy, fixed income securities include securities issued or guaranteed by the U.S. Government and its agencies or instrumentalities, municipal bonds, corporate bonds, residential and commercial mortgage-backed securities, asset-backed securities, convertible securities, trust preferred securities, loan participations and assignments, and U.S. dollar-denominated foreign debt securities. The Fund typically will also invest in exchange-traded funds that invest in such instruments, preferred stocks and hybrid preferred securities. Additionally, the Fund will invest up to 15% of its net assets in foreign exchange spot transactions (including with respect to emerging market currencies) and derivative instruments, such as options, futures contracts, forward contracts or swap agreements (including non-deliverable forwards and credit default swaps), for bona fide hedging purposes, to gain exposure to certain markets or segments of markets, and for speculative purposes. The Fund may also purchase or sell securities or other assets on a when-issued or delayed delivery basis.

While the Fund primarily invests in fixed income securities rated investment grade by Moody’s Investors Service, Inc. (“Moody’s”), or equivalently rated by S&P Global Ratings (“S&P”) or Fitch, Inc. (“Fitch”), it may invest to a lesser extent in high yield instruments (also known as “junk bonds”). The Fund may borrow money for, among other reasons, cash management purposes, to obtain leverage and to meet redemptions.

MFIM’s investment philosophy and process for selecting investments for the Fund generally includes a neutral duration policy, meaning that MFIM does not shorten or lengthen the Fund’s duration based on interest rate forecasts, but MFIM expects that the Fund’s duration may vary within two years (plus or minus) of the duration of the benchmark. MFIM strives to diversify at the sector, industry and issuer level when constructing the Fund’s portfolio. At the sector level, MFIM starts with the benchmark index weightings, modifies the index weightings to achieve what it believes will produce the most favorable risk-adjusted returns based

on current market conditions and outlook, and then tactically adjusts sector weightings as market opportunities present themselves. MFIM believes the majority of available excess returns can be captured through sector allocation and specific security selection. This approach is designed to capture the bulk of the excess returns available in the fixed income market while minimizing the variability of those returns relative to the Fund’s benchmark. MFIM believes the key to this investment process is the responsiveness, focus and analysis provided by its in-house sector specialists, credit analysts and trading professionals.

MFIM will target spot transactions and derivative instruments on behalf of the Fund that it believes will generate consistent alpha (i.e., outperformance) in all market conditions. MFIM will allocate capital between fundamental and technical currency strategies, and will aim to profit from short- and medium-term moves in various markets’ currency pairs. When investing in high yield bonds on behalf of the Fund, MFIM will target instruments that have individual yield premiums which MFIM believes are favorable and which are viewed by MFIM as having a comparable or lower probability of default and/or the risk of loss compared to their peer group.

The Fund may invest in cash or money market instruments for the purpose of meeting redemption requests or making other anticipated cash payments.

Risk Narrative [Text Block]

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As with all mutual funds, there is no guarantee that the Fund will achieve its investment objective. You could lose money by investing in the Fund. A Fund share is not a bank deposit and it is not insured or guaranteed by the FDIC or any government agency. The principal risk factors affecting shareholders’ investments in the Fund are set forth below.

Credit Risk — The risk that the issuer of a security or the counterparty to a contract will default or otherwise become unable to honor a financial obligation.

Corporate Fixed Income Securities Risk — Corporate fixed income securities respond to economic developments, especially changes in interest rates, as well as perceptions of the creditworthiness and business prospects of individual issuers.

Below Investment Grade Securities (Junk Bonds) Risk — Fixed income securities rated below investment grade (junk bonds) involve greater risks of default or downgrade and are generally more volatile than investment grade securities because the prospect for repayment of principal and interest of many of these securities is speculative. Because these securities typically offer a higher rate of return to compensate investors for these risks, they are sometimes referred to as “high yield bonds,” but there is no guarantee that an investment in these securities will result in a high rate of return.

Bank Loans Risk — Investments in bank loans (through both assignments and participations) are generally subject to the same risks as investments in other types of debt instruments, including, in many cases, investments in junk bonds. There may be limited public information available regarding bank loans and bank loans may be difficult to value. If the Fund holds a bank loan through another financial institution, or relies on a financial institution to administer the loan, its receipt of principal and interest on the loan may be subject to the credit risk of that financial institution. It is possible that any collateral securing a loan may be insufficient or unavailable to the Fund, and that the Fund’s rights to collateral may be limited by bankruptcy or insolvency laws. In addition, the secondary market for bank loans may be subject to irregular trading activity, wide bid/ask spreads, and extended trade settlement periods, which may cause the Fund to be unable to realize the full value of its investment in a bank loan.

Bank loans may not be considered “securities,” and purchasers, such as the Fund, therefore may not be entitled to rely on the anti-fraud protections of the federal securities laws.

Hybrid Preferred Securities Risk — Hybrid preferred securities may be issued by corporations, generally in the form of interest-bearing instruments with preferred securities characteristics, or by an affiliated trust or partnership of the corporation, generally in the form of preferred interests in subordinated business trusts or similarly structured securities. Although hybrid preferred security holders generally have claims to assets in a corporate liquidation that are senior to those of traditional preferred securities, the claims of such holders are generally still subordinate to those of senior debt holders.

Trust Preferred Securities Risk — Trust preferred securities are preferred stocks issued by a special purpose trust subsidiary backed by subordinated debt of the corporate parent. MFIM considers trust preferred securities to be debt securities. Trust

preferred securities are subject to increased credit risk and market value volatility, as well as the risk that the Fund may have to liquidate other investments in order to satisfy the distribution requirements applicable to regulated investment companies (“RICs”) within the meaning of Subchapter M of the Internal Revenue Code of 1986, as amended (the “Code”) if the trust preferred security or the subordinated debt is treated as an original issue discount obligation, and thereby causes the Fund to accrue interest income without receiving corresponding cash payments. There is also the risk that the underlying obligations, and thus the trust preferred securities, may be prepaid after a stated call date or as a result of certain tax or regulatory events, resulting in a lower yield to maturity.

Fixed Income Market Risk — The prices of the Fund’s fixed income securities respond to economic developments, particularly interest rate changes, as well as to perceptions about the creditworthiness of individual issuers, including governments and their agencies. Generally, the Fund’s fixed income securities will decrease in value if interest rates rise and vice versa. In a low interest rate environment, risks associated with rising rates are heightened. Declines in dealer market-making capacity as a result of structural or regulatory changes could decrease liquidity and/or increase volatility in the fixed income markets. In the case of foreign securities, price fluctuations will reflect international economic and political events, as well as changes in currency valuations relative to the U.S. dollar. In response to these events, the Fund’s value may fluctuate and/or the Fund may experience increased redemptions from shareholders, which may impact the Fund’s liquidity or force the Fund to sell securities into a declining or illiquid market.

Foreign Currency Risk — Foreign currency risk is the risk that foreign currencies will decline in value relative to the U.S. dollar or, in the case of hedging positions, that the U.S. dollar will decline in value relative to the currency hedged. Due to the Fund’s active positions in currencies, it will be subject to the risk that currency exchange rates may fluctuate in response to, among other things, changes in interest rates, intervention (or failure to intervene) by U.S. or foreign governments, central banks or supranational entities, or by the imposition of currency controls or other political developments in the United States or abroad.

Market Risk — The risk that the market value of a security or other Fund holding may move up and down, sometimes rapidly and unpredictably. Market risk may affect a single issuer, an industry, a sector or the bond market as a whole. In addition, the impact of

any epidemic, pandemic or natural disaster, or widespread fear that such events may occur, could negatively affect the global economy, as well as the economies of individual countries, the financial performance of individual companies and sectors, and the markets in general in significant and unforeseen ways. Any such impact could adversely affect the prices and liquidity of the securities and other instruments in which the Fund invests, which in turn could negatively impact the Fund’s performance and cause losses on your investment in the Fund.

Interest Rate Risk — The risk that a rise in interest rates will cause a fall in the value of fixed income securities, including U.S. Government securities, in which the Fund invests. Although U.S. Government securities are considered to be among the safest investments, they are not guaranteed against price movements due to changing interest rates. A low interest rate environment may present greater interest rate risk because there may be a greater likelihood of rates increasing and rates may increase more rapidly.

Investment Style Risk — The risk that fixed income securities may underperform other segments of the fixed income markets or the fixed income markets as a whole.

Liquidity Risk — The risk that certain securities or other Fund holdings may be difficult or impossible to sell at the time and the price that the seller would like. The seller may have to lower the price, sell other securities instead or forego an investment opportunity, any of which could have a negative effect on Fund management or performance.

Extension Risk — The risk that rising interest rates may extend the duration of a fixed income security, typically reducing the security’s value.

Prepayment Risk — The risk that, in a declining interest rate environment, fixed income securities with stated interest rates may have the principal paid earlier than expected, requiring the Fund to invest the proceeds at generally lower interest rates.

Leverage Risk — The Fund’s use of borrowing, derivatives and when-issued, delayed delivery or forward commitment transactions may result in the Fund’s total investment exposure substantially exceeding the value of its portfolio securities and, in certain cases, the Fund’s investment returns substantially depending on the performance of securities that the Fund may not directly own. The use of leverage can amplify the effects of market volatility on the Fund’s share price and may also cause the Fund to liquidate portfolio positions when it would not be advantageous to do so in order to satisfy its obligations. In the

case of borrowings, the Fund may experience losses if its borrowing costs exceed the investment returns on the securities purchased with the borrowed money. The Fund’s use of leverage may result in a heightened risk of investment loss.

Derivatives Risk — The Fund’s use of futures, forwards, options and swaps is subject to market risk, leverage risk, correlation risk and liquidity risk. Leverage risk, liquidity risk and market risk are described below. Many over-the-counter (OTC) derivative instruments will not have liquidity beyond the counterparty to the instrument. Correlation risk is the risk that changes in the value of the derivative may not correlate perfectly with the underlying asset, rate or index. The Fund’s use of OTC forward contracts, options and swaps is also subject to credit risk and valuation risk. Valuation risk is described below. Credit risk is described above. Each of these risks could cause the Fund to lose more than the principal amount invested in a derivative instrument. Some derivatives have the potential for unlimited loss, regardless of the size of the Fund’s initial investment. The other parties to certain derivative contracts present the same types of credit risk as issuers of fixed income securities. The Fund’s use of derivatives may also increase the amount of taxes payable by shareholders. Both U.S. and non-U.S. regulators have adopted and are in the process of adopting and implementing regulations governing derivatives markets, the ultimate impact of which remains unclear. Additionally, some derivatives, such as non-deliverable forwards, require funds to be posted by the Fund when positions are opened. This creates a risk that the funds may not be returned to the Fund even if the position is closed.

Convertible Securities and Preferred Stocks Risk — Convertible and preferred securities have many of the same characteristics as stocks, including many of the same risks. In addition, convertible bonds may be more sensitive to changes in interest rates than stocks. Convertible bonds may also have credit ratings below investment grade, meaning that they carry a higher risk of failure by the issuer to pay principal and/or interest when due.

Duration Risk — The longer-term securities in which the Fund may invest tend to be more volatile than shorter-term securities. A portfolio with a longer average portfolio duration is more sensitive to changes in interest rates than a portfolio with a shorter average portfolio duration.

Asset-Backed Securities Risk — Payment of principal and interest on asset-backed securities is dependent largely on the cash

flows generated by the assets backing the securities. Securitization trusts generally do not have any assets or sources of funds other than receivables and related property they own, and asset-backed securities are generally not insured or guaranteed by the related sponsor or any other entity. Asset-backed securities may be more illiquid than more conventional types of fixed income securities that the Fund may acquire.

Mortgage-Backed Securities Risk — Mortgage-backed securities are affected significantly by the rate of prepayments and modifications of the mortgage loans backing those securities, as well as by other factors such as borrower defaults, delinquencies, realized or liquidation losses and other shortfalls. Mortgage-backed securities are particularly sensitive to prepayment risk, which is described below, given that the term to maturity for mortgage loans is generally substantially longer than the expected lives of those securities; however, the timing and amount of prepayments cannot be accurately predicted. The timing of changes in the rate of prepayments of the mortgage loans may significantly affect the Fund’s actual yield to maturity on any mortgage-backed securities, even if the average rate of principal payments is consistent with the Fund’s expectation. Along with prepayment risk, mortgage-backed securities are significantly affected by interest rate risk, which is described above. In a low interest rate environment, mortgage loan prepayments would generally be expected to increase due to factors such as refinancings and loan modifications at lower interest rates. In contrast, if prevailing interest rates rise, prepayments of mortgage loans would generally be expected to decline and therefore extend the weighted average lives of mortgage-backed securities held or acquired by the Fund.

Municipal Securities Risk — Municipal securities, like other fixed income securities, rise and fall in value in response to economic and market factors, primarily changes in interest rates, and actual or perceived credit quality. Rising interest rates will generally cause municipal securities to decline in value. Longer-term securities respond more sharply to interest rate changes than do shorter-term securities. A municipal security will also lose value if, due to rating downgrades or other factors, there are concerns about the issuer’s current or future ability to make principal or interest payments. State and local governments rely on taxes and, to some extent, revenues from private projects financed by municipal securities, to pay interest and principal on municipal debt. Poor statewide or local economic results or changing political sentiments may reduce tax revenues and

increase the expenses of municipal issuers, making it more difficult for them to meet their obligations. Actual or perceived erosion of the creditworthiness of municipal issuers may reduce the value of the Fund’s holdings. As a result, the Fund will be more susceptible to factors that adversely affect issuers of municipal obligations than a mutual fund that does not have as great a concentration in municipal obligations.

When-Issued and Delayed Delivery Securities Risk — When-issued and delayed delivery securities involve the risk that the security the Fund buys will lose value prior to its delivery.

Foreign Investment/Emerging Markets Risk — The risk that non-U.S. securities may be subject to additional risks due to, among other things, political, social and economic developments abroad, currency movements, and different legal, regulatory and tax environments. In addition, periodic U.S. Government restrictions on investments in issuers from certain foreign countries may require the Fund to sell such investments at inopportune times, which could result in losses to the Fund. In addition, periodic U.S. Government restrictions on investments in issuers from certain foreign countries may require the Fund to sell such investments at inopportune times, which could result in losses to the Fund. These additional risks may be heightened with respect to emerging market countries because political turmoil and rapid changes in economic conditions are more likely to occur in these countries.

Exchange-Traded Funds (ETFs) Risk — The risks of owning shares of an ETF generally reflect the risks of owning the underlying securities in which the ETF invests, although lack of liquidity in an ETF could result in its value being more volatile than the underlying portfolio securities. When the Fund invests in an ETF, in addition to directly bearing the expenses associated with its own operations, it will bear a pro rata portion of the ETF’s expenses.

Money Market Instruments Risk — The value of money market instruments may be affected by changing interest rates and by changes in the credit ratings of the investments. An investment in a money market fund is not a bank deposit and is not insured or guaranteed by any bank, the FDIC or any other government agency. A money market fund’s sponsor has no legal obligation to provide financial support to the fund, and there should be no expectation that the sponsor will provide financial support to the fund at any time. Certain money market funds float their net asset value while others seek to preserve the value of investments at a stable net

asset value (typically, $1.00 per share). An investment in a money market fund, even an investment in a fund seeking to maintain a stable net asset value per share, is not guaranteed and it is possible for the Fund to lose money by investing in these and other types of money market funds. If the liquidity of a money market fund’s portfolio deteriorates below certain levels, the money market fund may suspend redemptions (i.e., impose a redemption gate) and thereby prevent the Fund from selling its investment in the money market fund or impose a fee of up to 2% on amounts the Fund redeems from the money market fund (i.e., impose a liquidity fee). These measures may result in an investment loss or prohibit the Fund from redeeming shares when MFIM would otherwise redeem shares. Money market funds and the securities they invest in are subject to comprehensive regulations. The enactment of new legislation or regulations, as well as changes in interpretation and enforcement of current laws, may affect the manner of operation, performance and/or yield of money market funds.

Valuation Risk — The risk that a security may be difficult to value. The Fund may value certain securities at a price higher than the price at which they can be sold.

U.S. Government Securities Risk — Although U.S. Government securities are considered to be among the safest investments, they are not guaranteed against price movements due to changing interest rates. Obligations issued by some U.S. Government agencies are backed by the U.S. Treasury, while others are backed solely by the ability of the agency to borrow from the U.S. Treasury or by the agency’s own resources.

Risk Not Insured Depository Institution [Text]

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A Fund share is not a bank deposit and it is not insured or guaranteed by the FDIC or any government agency.

Performance Narrative [Text Block]

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The bar chart and the performance table below illustrate the risks and volatility of an investment in the Fund by showing the Fund’s Institutional Shares performance from year to year and by showing how the Fund’s average annual total returns for 1 year and since inception compare with those of a broad measure of market performance. Of course, the Fund’s past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future.

Updated performance information is available by calling 833-MESIROW (833-637-4769) or on the Internet at www.mesirow.com.

Performance Availability Phone [Text]

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833-MESIROW (833-637-4769)

Performance Past Does Not Indicate Future [Text]

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Of course, the Fund’s past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future.

Performance Table Heading

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Average Annual Returns for Periods Ended December 31, 2021

Performance Table Not Relevant to Tax Deferred

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After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts (“IRAs”).

Label

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Bloomberg U.S. Aggregate Index

Since Inception

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2.56%

Trading Symbol

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MFBIX

Management Fees (as a percentage of Assets)

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0.37%

Other Expenses (as a percentage of Assets):

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1.51%

Fee Waiver or Reimbursement

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(1.34%)

^[1]

Expense Example, with Redemption, 1 Year

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$ 55

Expense Example, with Redemption, 5 Years

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891

Annual Return 2020

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8.45%

Highest Quarterly Return, Label

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BEST QUARTER

Highest Quarterly Return

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7.43%

Lowest Quarterly Return, Date

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Mar. 31, 2020

Label

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Fund Returns Before Taxes

Since Inception

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3.40%

Label

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Fund Returns After Taxes

Since Inception

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2.46%

Label

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Fund Returns After Taxes on Distributions and Sale of Fund Shares

Since Inception

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2.26%

Trading Symbol

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MFBVX

Management Fees (as a percentage of Assets)

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0.37%

Other Expenses (as a percentage of Assets):

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1.50%

Fee Waiver or Reimbursement

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(1.33%)

^[1]

Expense Example, with Redemption, 1 Year

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$ 81

Expense Example, with Redemption, 5 Years

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1,017

Label

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Fund Returns Before Taxes

Since Inception

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3.13%

Risk/Return [Heading]

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Mesirow High Yield Fund

Objective, Primary [Text Block]

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The Mesirow High Yield Fund (the “High Yield Fund” or the “Fund”) seeks to provide a high level of current income consistent with the preservation of principal.

Expense Narrative [Text Block]

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This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Operating Expenses Caption [Text]

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

Portfolio Turnover [Heading]

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Portfolio Turnover

Portfolio Turnover, Rate

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71.00%

Expense Example Narrative [Text Block]

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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 and that the Fund’s operating expenses (including one year of capped expenses in each period) remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy Narrative [Text Block]

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Under normal circumstances, the Fund invests at least 80% of its net assets, plus any borrowings for investment purposes, in high yield instruments (also known as “junk bonds”) and other financial instruments with economic characteristics similar to such instruments, such as derivatives and exchange-traded funds

(“ETFs”). This investment policy may be changed by the Fund upon 60 days’ prior written notice to shareholders.

High yield instruments in which the Fund may invest include domestic and foreign bonds (including corporate bonds), convertible securities, forward commitments, loan participations and assignments, preferred stocks and privately issued securities (e.g., Rule 144A securities) that are rated below investment grade by Moody’s Investors Service, Inc. (“Moody’s”), or equivalently rated by S&P Global Ratings (“S&P”) or Fitch, Inc. (“Fitch”), or, if unrated, determined by MFIM to be of comparable quality.

The Fund may invest the remainder of its assets in investment grade instruments including securities issued or guaranteed by the U.S. Government and its agencies or instrumentalities, municipal bonds, corporate bonds, residential and commercial mortgage-backed securities, asset-backed securities, loan participations and assignments, U.S. dollar-denominated foreign debt securities and ETFs that invest in such instruments. The Fund may also invest up to 5% of its net assets in foreign currency-denominated securities. The Fund may also invest up to 10% of its net assets in securities and instruments that are economically tied to emerging market countries, which MFIM defines as those countries that are: (i) characterized as developing or emerging by any of the World Bank, the United Nations, the International Finance Corporation, or the European Bank for Reconstruction and Development; (ii) included in an emerging markets index by a recognized index provider; or (iii) countries with similar developing or emerging characteristics as countries classified as emerging market countries pursuant to sub-paragraph (i) and (ii) above, in each case determined at the time of purchase. The Fund may also invest in equity securities, which are ownership interests in a public or private company or partnership and consist of common stocks, warrants and rights to acquire common stock, and investments in master limited partnerships (“MLPs”). The Fund may invest in securities of companies with any market capitalization.

The Fund also may invest up to 5% of its net assets in derivative instruments, such as options, futures contracts or swap agreements, for bona fide hedging purposes, to gain exposure to certain markets or segments of markets, and for speculative purposes. From time to time, the Fund may experience significant inflows; if this occurs, the Fund may, on a temporary or interim basis, invest these new assets (potentially in an amount which may approach up to 50% of the Fund’s total net assets if new flows were extremely large relative to

the Fund’s current assets) in a combination of derivative instruments and other investment companies, including ETFs, until such time as MFIM can identify and invest in appropriate high yield instruments in accordance with the Fund’s principal strategy. The Fund may purchase or sell securities or other assets on a when-issued, delayed delivery or forward commitment basis. The Fund may borrow money for, among other reasons, cash management purposes, to obtain leverage and to meet redemptions.

The average portfolio duration of the Fund normally varies within two years (plus or minus) of the portfolio duration of the securities comprising the Bloomberg U.S. Corporate High-Yield Index, which as of September 30, 2021 was 3.9 years. Duration is a measure of the expected life of a fixed income security that is used to determine the sensitivity of a security’s price to changes in interest rates.

In selecting investments for the Fund, MFIM will consider the risks and opportunities presented by the industries within the high yield universe. MFIM evaluates the bond issuers within the selected industries and identifies those investments which MFIM believes have favorable risk reward characteristics and match MFIM’s investing philosophy. MFIM evaluates various criteria such as historical and future expected financial performance, management tenure and experience, capital structure, free cash flow generation, barriers to entry, security protections, yield and relative value, and ownership structure. MFIM targets investments that have individual yield premiums which appear to be favorable and are viewed by MFIM as having a comparable or lower probability of default and/or loss risk.

The Fund may invest in cash or money market instruments for the purpose of meeting redemption requests or making other anticipated cash payments.

Risk Narrative [Text Block]

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As with all mutual funds, there is no guarantee that the Fund will achieve its investment objective. You could lose money by investing in the Fund. A Fund share is not a bank deposit and it is not insured or guaranteed by the FDIC or any government agency. The principal risk factors affecting shareholders’ investments in the Fund are set forth below.

Below Investment Grade Securities (Junk Bonds) Risk — Fixed income securities rated below investment grade (junk bonds) involve greater risks of default or downgrade and are generally more

volatile than investment grade securities because the prospect for repayment of principal and interest of many of these securities is speculative. Because these securities typically offer a higher rate of return to compensate investors for these risks, they are sometimes referred to as “high yield bonds,” but there is no guarantee that an investment in these securities will result in a high rate of return.

Market Risk — The risk that the market value of a security may move up and down, sometimes rapidly and unpredictably. Market risk may affect a single issuer, an industry, a sector or the bond market as a whole. In addition, the impact of any epidemic, pandemic or natural disaster, or widespread fear that such events may occur, could negatively affect the global economy, as well as the economies of individual countries, the financial performance of individual companies and sectors, and the markets in general in significant and unforeseen ways. Any such impact could adversely affect the prices and liquidity of the securities and other instruments in which the Fund invests, which in turn could negatively impact the Fund’s performance and cause losses on your investment in the Fund.

Credit Risk — The risk that the issuer of a security or the counterparty to a contract will default or otherwise become unable to honor a financial obligation.

Fixed Income Market Risk — The prices of the Fund’s fixed income securities respond to economic developments, particularly interest rate changes, as well as to perceptions about the creditworthiness of individual issuers, including governments and their agencies. Generally, the Fund’s fixed income securities will decrease in value if interest rates rise and vice versa. In a low interest rate environment, risks associated with rising rates are heightened. Declines in dealer market-making capacity as a result of structural or regulatory changes could decrease liquidity and/or increase volatility in the fixed income markets. In the case of foreign securities, price fluctuations will reflect international economic and political events, as well as changes in currency valuations relative to the U.S. dollar. In response to these events, the Fund’s value may fluctuate and/or the Fund may experience increased redemptions from shareholders, which may impact the Fund’s liquidity or force the Fund to sell securities into a declining or illiquid market.

Corporate Fixed Income Securities Risk — Corporate fixed income securities respond to economic developments, especially changes

in interest rates, as well as perceptions of the creditworthiness and business prospects of individual issuers.

Bank Loans Risk — Investments in bank loans (through both assignments and participations) are generally subject to the same risks as investments in other types of debt instruments, including, in many cases, investments in junk bonds. There may be limited public information available regarding bank loans and bank loans may be difficult to value. If the Fund holds a bank loan through another financial institution, or relies on a financial institution to administer the loan, its receipt of principal and interest on the loan may be subject to the credit risk of that financial institution. It is possible that any collateral securing a loan may be insufficient or unavailable to the Fund, and that the Fund’s rights to collateral may be limited by bankruptcy or insolvency laws. In addition, the secondary market for bank loans may be subject to irregular trading activity, wide bid/ask spreads, and extended trade settlement periods, which may cause the Fund to be unable to realize the full value of its investment in a bank loan.

Bank loans may not be considered “securities,” and purchasers, such as the Fund, therefore may not be entitled to rely on the anti-fraud protections of the federal securities laws.

Prepayment Risk — The risk that, in a declining interest rate environment, fixed income securities with stated interest rates may have the principal paid earlier than expected, requiring the Fund to invest the proceeds at generally lower interest rates.

Extension Risk — The risk that rising interest rates may extend the duration of a fixed income security, typically reducing the security’s value.

Investment Style Risk — The risk that high yield fixed income securities may underperform other segments of the fixed income markets or the fixed income markets as a whole.

Interest Rate Risk — The risk that a rise in interest rates will cause a fall in the value of fixed income securities, including U.S. Government securities, in which the Fund invests. Although U.S. Government securities are considered to be among the safest investments, they are not guaranteed against price movements due to changing interest rates. A low interest rate environment may present greater interest rate risk because there may be a greater likelihood of rates increasing and rates may increase more rapidly.

Duration Risk — The longer-term securities in which the Fund may invest tend to be more volatile than shorter-term securities. A portfolio with a longer average portfolio duration is more sensitive to changes in interest rates than a portfolio with a shorter average portfolio duration.

Liquidity Risk — The risk that certain securities may be difficult or impossible to sell at the time and the price that the seller would like. The seller may have to lower the price, sell other securities instead or forego an investment opportunity, any of which could have a negative effect on Fund management or performance.

Valuation Risk — The risk that a security may be difficult to value. The Fund may value certain securities at a price higher than the price at which they can be sold.

Exchange-Traded Funds (ETFs) Risk — The risks of owning shares of an ETF generally reflect the risks of owning the underlying securities in which the ETF invests, although lack of liquidity in an ETF could result in its value being more volatile than the underlying portfolio securities. When the Fund invests in an ETF, in addition to directly bearing the expenses associated with its own operations, it will bear a pro rata portion of the ETF’s expenses.

Money Market Instruments Risk — The value of money market instruments may be affected by changing interest rates and by changes in the credit ratings of the investments. An investment in a money market fund is not a bank deposit and is not insured or guaranteed by any bank, the FDIC or any other government agency. A money market fund’s sponsor has no legal obligation to provide financial support to the fund, and there should be no expectation that the sponsor will provide financial support to the fund at any time. Certain money market funds float their net asset value while others seek to preserve the value of investments at a stable net asset value (typically, $1.00 per share). An investment in a money market fund, even an investment in a fund seeking to maintain a stable net asset value per share, is not guaranteed and it is possible for the Fund to lose money by investing in these and other types of money market funds. If the liquidity of a money market fund’s portfolio deteriorates below certain levels, the money market fund may suspend redemptions (i.e., impose a redemption gate) and thereby prevent the Fund from selling its investment in the money market fund or impose a fee of up to 2% on amounts the Fund redeems from the money market fund (i.e., impose a liquidity fee). These measures may result in an investment loss or prohibit the

Fund from redeeming shares when MFIM would otherwise redeem shares. Money market funds and the securities they invest in are subject to comprehensive regulations. The enactment of new legislation or regulations, as well as changes in interpretation and enforcement of current laws, may affect the manner of operation, performance and/or yield of money market funds.

Leverage Risk — The Fund’s use of borrowing, derivatives and when-issued, delayed delivery or forward commitment transactions may result in the Fund’s total investment exposure substantially exceeding the value of its portfolio securities and, in certain cases, the Fund’s investment returns depending substantially on the performance of securities that the Fund may not directly own. The use of leverage can amplify the effects of market volatility on the Fund’s share price and may also cause the Fund to liquidate portfolio positions when it would not be advantageous to do so in order to satisfy its obligations. In the case of borrowings, the Fund may experience losses if its borrowing costs exceed the investment returns on the securities purchased with the borrowed money. The Fund’s use of leverage may result in a heightened risk of investment loss.

Foreign Currency Risk — As a result of the Fund’s investments in securities denominated in, and/or receiving revenues in, foreign currencies, the Fund will be subject to currency risk. Currency risk is the risk that foreign currencies will decline in value relative to the U.S. dollar, in which case the dollar value of an investment in the Fund would be adversely affected.

Asset-Backed Securities Risk — Payment of principal and interest on asset-backed securities is dependent largely on the cash flows generated by the assets backing the securities. Securitization trusts generally do not have any assets or sources of funds other than receivables and related property they own, and asset-backed securities are generally not insured or guaranteed by the related sponsor or any other entity. Asset-backed securities may be more illiquid than more conventional types of fixed income securities that the Fund may acquire.

Convertible Securities and Preferred Stocks Risk — Convertible and preferred securities have many of the same characteristics as stocks, including many of the same risks. In addition, convertible securities may be more sensitive to changes in interest rates than stocks. Convertible securities may also have credit ratings below

investment grade, meaning that they carry a higher risk of failure by the issuer to pay principal and/or interest when due.

Derivatives Risk — The Fund’s use of futures, options and swaps is subject to market risk, leverage risk, correlation risk and liquidity risk. Leverage risk, liquidity risk and market risk are described below. Many over-the-counter (OTC) derivative instruments will not have liquidity beyond the counterparty to the instrument. Correlation risk is the risk that changes in the value of the derivative may not correlate perfectly with the underlying asset, rate or index. The Fund’s use of OTC options and swaps is also subject to credit risk and valuation risk. Valuation risk is described below. Credit risk is described above. Each of these risks could cause the Fund to lose more than the principal amount invested in a derivative instrument. Some derivatives have the potential for unlimited loss, regardless of the size of the Fund’s initial investment. The other parties to certain derivative contracts present the same types of credit risk as issuers of fixed income securities. The Fund’s use of derivatives may also increase the amount of taxes payable by shareholders. Both U.S. and non-U.S. regulators have adopted and are in the process of adopting and implementing regulations governing derivatives markets, the ultimate impact of which remains unclear.

Foreign Investment/Emerging Markets Risk — The risk that non-U.S. securities may be subject to additional risks due to, among other things, political, social and economic developments abroad, currency movements, and different legal, regulatory and tax environments. In addition, periodic U.S. Government restrictions on investments in issuers from certain foreign countries may require the Fund to sell such investments at inopportune times, which could result in losses to the Fund. In addition, periodic U.S. Government restrictions on investments in issuers from certain foreign countries may require the Fund to sell such investments at inopportune times, which could result in losses to the Fund. These additional risks may be heightened with respect to emerging market countries because political turmoil and rapid changes in economic conditions are more likely to occur in these countries.

Mortgage-Backed Securities Risk — Mortgage-backed securities are affected significantly by the rate of prepayments and modifications of the mortgage loans backing those securities, as well as by other factors such as borrower defaults, delinquencies, realized or liquidation losses and other shortfalls. Mortgage-backed securities are particularly sensitive to prepayment risk, which is described below, given that the term to maturity for mortgage

loans is generally substantially longer than the expected lives of those securities; however, the timing and amount of prepayments cannot be accurately predicted. The timing of changes in the rate of prepayments of the mortgage loans may significantly affect the Fund’s actual yield to maturity on any mortgage-backed securities, even if the average rate of principal payments is consistent with the Fund’s expectation. Along with prepayment risk, mortgage-backed securities are significantly affected by interest rate risk, which is described above. In a low interest rate environment, mortgage loan prepayments would generally be expected to increase due to factors such as refinancings and loan modifications at lower interest rates. In contrast, if prevailing interest rates rise, prepayments of mortgage loans would generally be expected to decline and therefore extend the weighted average lives of mortgage-backed securities held or acquired by the Fund.

Municipal Securities Risk — Municipal securities, like other fixed income securities, rise and fall in value in response to economic and market factors, primarily changes in interest rates, and actual or perceived credit quality. Rising interest rates will generally cause municipal securities to decline in value. Longer-term securities respond more sharply to interest rate changes than do shorter-term securities. A municipal security will also lose value if, due to rating downgrades or other factors, there are concerns about the issuer’s current or future ability to make principal or interest payments. State and local governments rely on taxes and, to some extent, revenues from private projects financed by municipal securities, to pay interest and principal on municipal debt. Poor statewide or local economic results or changing political sentiments may reduce tax revenues and increase the expenses of municipal issuers, making it more difficult for them to meet their obligations. Actual or perceived erosion of the creditworthiness of municipal issuers may reduce the value of the Fund’s holdings. As a result, the Fund will be more susceptible to factors that adversely affect issuers of municipal obligations than a mutual fund that does not have as great a concentration in municipal obligations.

U.S. Government Securities Risk — Although U.S. Government securities are considered to be among the safest investments, they are not guaranteed against price movements due to changing interest rates. Obligations issued by some U.S. Government agencies are backed by the U.S. Treasury, while others are backed solely by the ability of the agency to borrow from the U.S. Treasury or by the agency’s own resources.

When-Issued and Delayed Delivery Securities and Forward Commitments Risk — When-issued and delayed delivery securities and forward commitments involve the risk that the security the Fund buys will lose value prior to its delivery.

Equity Market Risk — The risk that stock prices will fall over short or extended periods of time.

Small- and Mid-Capitalization Companies Risk — Small- and mid-capitalization companies in which the Fund may invest may be more vulnerable to adverse business or economic events than larger, more established companies. In particular, small- and mid-capitalization companies may have limited product lines, markets and financial resources and may depend upon a relatively small management group. Therefore, small- and mid-capitalization stocks may be more volatile than those of larger companies. Small- and mid-capitalization stocks may be traded over-the-counter or listed on an exchange.

Large Capitalization Risk — The risk that larger, more established companies may be unable to respond quickly to new competitive challenges such as changes in technology and consumer tastes. Larger companies also may not be able to attain the high growth rates of successful smaller companies.

Master Limited Partnerships (MLPs) Risk — MLPs are limited partnerships in which the ownership units are publicly traded. MLPs often own several properties or businesses (or own interests) that are related to oil and gas industries or other natural resources, but they also may finance other projects. To the extent that an MLP’s interests are all in a particular industry, the MLP will be negatively impacted by economic events adversely impacting that industry. Additional risks of investing in a MLP also include those involved in investing in a partnership as opposed to a corporation, such as limited control of management, limited voting rights and tax risks. MLPs may be subject to state taxation in certain jurisdictions, which will have the effect of reducing the amount of income paid by the MLP to its investors.

Privately Issued Securities Risk — Investment in privately placed securities may be less liquid than in publicly traded securities. Although these securities may be resold in privately negotiated transactions, the prices realized from these sales could be less than those originally paid by the Fund or less than what may be considered the fair value of such securities. Further, companies whose securities are not publicly traded may not be subject to the

disclosure and other investor protection requirements that might be applicable if their securities were publicly traded.

Warrants and Rights Risk — Warrants and rights may be more speculative than other types of investments. The price of a warrant or right may be more volatile than the price of its underlying security, and a warrant or right may offer greater potential for capital appreciation as well as capital loss. A warrant or right ceases to have value if it is not exercised prior to its expiration date.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

A Fund share is not a bank deposit and it is not insured or guaranteed by the FDIC or any government agency.

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and the performance table below illustrate the risks and volatility of an investment in the Fund by showing the Fund’s Institutional Shares performance from year to year and by showing how the Fund’s average annual total returns for 1 year and since inception compare with those of a broad measure of market performance. Of course, the Fund’s past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future.

Updated performance information is available by calling 833-MESIROW (833-637-4769) or on the Internet at www.mesirow.com.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

833-MESIROW (833-637-4769)

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Of course, the Fund’s past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future.

Performance Table Heading

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Average Annual Returns for Periods Ended December 31, 2021

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts (“IRAs”).

Label

rr_AverageAnnualReturnLabel

Bloomberg U.S. Corporate High Yield Index

Since Inception

rr_AverageAnnualReturnSinceInception

7.69%

Trading Symbol

dei_TradingSymbol

MFHIX

Management Fees (as a percentage of Assets)

rr_ManagementFeesOverAssets

0.55%

Other Expenses (as a percentage of Assets):

rr_OtherExpensesOverAssets

0.65%

Fee Waiver or Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.45%)

^[1]

Expense Example, with Redemption, 1 Year

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$ 77

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

616

Annual Return 2019

rr_AnnualReturn2019

12.99%

Annual Return 2021

rr_AnnualReturn2021

10.67%

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2020

Lowest Quarterly Return, Label

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WORST QUARTER

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(16.81%)

1 Year

rr_AverageAnnualReturnYear01

10.67%

Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 03, 2018

Prospectus [Line Items]

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1 Year

rr_AverageAnnualReturnYear01

6.96%

Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 03, 2018

Prospectus [Line Items]

rr_ProspectusLineItems

1 Year

rr_AverageAnnualReturnYear01

6.33%

Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 03, 2018

Prospectus [Line Items]

rr_ProspectusLineItems

Redemption Fee (as a percentage of Amount Redeemed)

rr_RedemptionFeeOverRedemption

(1.00%)

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Expenses (as a percentage of Assets)

rr_ExpensesOverAssets

1.43%

Net Expenses (as a percentage of Assets)

rr_NetExpensesOverAssets

1.00%

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

410

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,676

1 Year

rr_AverageAnnualReturnYear01

10.53%

Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 03, 2018

Prospectus [Line Items]

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Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Expense [Heading]

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Fund Fees and Expenses

Shareholder Fees Caption [Text]

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Shareholder Fees (fees paid directly from your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2023

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in total annual fund operating expenses or in the example, affect the Fund’s performance. During its most recent fiscal year, the Fund’s portfolio turnover rate was 108% of the average value of its portfolio.

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Risk [Heading]

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Principal Risks

Risk Lose Money [Text]

rr_RiskLoseMoney

You could lose money by investing in the Fund.

Bar Chart and Performance Table [Heading]

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Performance Information

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart and the performance table below illustrate the risks and volatility of an investment in the Fund by showing the Fund’s Institutional Shares performance from year to year and by showing how the Fund’s average annual total returns for 1 year and since inception compare with those of a broad measure of market performance.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.mesirow.com

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

BEST QUARTER	WORST QUARTER
30.92%	(32.67)%
(12/31/2020)	(3/31/2020)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

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

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

This table compares the Fund’s average annual total returns for the periods ended December 31, 2021 to those of an appropriate broad-based index.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s

tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts (“IRAs”). After tax returns are shown for Institutional Shares only. After tax returns for Investor Shares will vary.

Prospectus [Line Items]

rr_ProspectusLineItems

1 Year

rr_AverageAnnualReturnYear01

14.82%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 19, 2018

^[2]

Prospectus [Line Items]

rr_ProspectusLineItems