497

EXPLANATORY NOTE

Attached for filing are exhibits containing interactive data format risk/return summary information that mirrors the risk/return summary information included in a supplement to the Class A, Class B and Class C Prospectus and to the Class I and Class R Prospectus, each dated February 29, 2012, for Calamos Growth and Income Fund, Calamos Global Growth and Income Fund, Calamos Convertible Fund and Calamos Market Neutral Income Fund, each a series of Calamos Investment Trust, filed with the Securities and Exchange Commission on December 19, 2012 (Accession No. 0001193125-12-508259), the purpose of which was to make certain clarifications to each Fund’s risk/return summary information and to re-open Calamos Market Neutral Income Fund to new investors.

XML

CALAMOS^® FAMILY OF FUNDS

Supplement dated December 19, 2012 to the

CALAMOS^® FAMILY OF FUNDS Prospectuses for

Class A, B, C and Class I and R dated February 29, 2012, as previously supplemented on

October 16, 2012, August 31, 2012, July 2, 2012, May 15, 2012 and March 30, 2012 and

the Statement of Additional Information dated February 29, 2012,

as previously supplemented on May 15, 2012

Effective January 2, 2013, the Principal Investment Strategies and Principal Risks sections for Market Neutral Income Fund on page 64 of the Class A, B and C Prospectus, and on page 54 of the Class I and R prospectus shall be replaced in their entirety as follows:

Principal Investment Strategies

The Fund's investment strategy can be characterized as "market neutral" because it seeks to achieve maximum current income while maintaining a low correlation to the fluctuations of the U.S. equity market as a whole. The Fund invests in (i) equities (ii) convertible securities of U.S. companies without regard to market capitalization and employs (iii) short selling to enhance income and hedge against market risk. The convertible securities in which the Fund invests may be either debt securities or preferred stocks that can be exchanged for common stock. The average term to maturity of the convertible securities purchased by the Fund will typically range from two to ten years.

The Fund may seek to generate income from option premiums by writing (selling) options. This would include the use of both call and put options. The Fund may write call options (i) on a portion of the equity securities (including securities that are convertible into equity securities) in the Fund's portfolio and (ii) on broad-based securities indexes (such as the S&P 500 or MSCI EAFE) or ETFs (exchange traded funds). In addition, to seek to offset some of the risk of a potential decline in value of certain long positions, the Fund may also purchase put options on individual securities, broad-based securities indexes (such as the S&P 500), or ETFs.

The Fund may invest without limit in high yield fixed-income securities (often referred to as "junk bonds"). In addition, the Fund may engage in active and frequent trading of portfolio securities. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes.

Principal Risks

An investment in the Fund is subject to risks, and you could lose money on your investment in the Fund. There can be no assurance that the Fund will achieve its investment objective. The risks associated with an investment in the Fund can increase during times of significant market volatility. Your 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. The principal risks of investing in the Fund include:

▪ Equity Securities Risk — The securities markets are volatile, and the market prices of the Fund's securities may decline generally. The price of equity securities fluctuates based on changes in a company's financial condition and overall market and economic conditions. If the market prices of the securities owned by the Fund fall, the value of your investment in the Fund will decline.

▪ Convertible Securities Risk — The value of a convertible security is influenced by changes in interest rates, with investment value declining as interest rates increase and increasing as interest rates decline. The credit standing of the issuer and other factors also may have an effect on the convertible security's investment value.

▪ Synthetic Convertible Instruments Risk — The value of a synthetic convertible instrument will respond differently to market fluctuations than a convertible security because a synthetic convertible instrument is composed of two or more separate securities, each with its own market value. In addition, if the value of the underlying common stock or the level of the index involved in the convertible component falls below the exercise price of the warrant or option, the warrant or option may lose all value.

▪ Convertible Hedging Risk — If the market price of the underlying common stock increases above the conversion price on a convertible security, the price of the convertible security will increase. The Fund's increased liability on any outstanding short position would, in whole or in part, reduce this gain.

▪ Covered Call Writing Risk — As the writer of a covered call option on a security, the Fund foregoes, during the option's life, the opportunity to profit from increases in the market value of the security, covering the call option above the sum of the premium and the exercise price of the call.

▪ Options Risk — The Fund's ability to close out its position as a purchaser or seller of an over-the-counter or exchange-listed put or call option is dependent, in part, upon the liquidity of the option market. There are significant differences between the securities and options markets that could result in an imperfect correlation among these markets, causing a given transaction not to achieve its objectives. The Fund's ability to utilize options successfully will depend on the ability of the Fund's investment adviser to predict pertinent market movements, which cannot be assured.

▪ Short Sale Risk — The Fund may incur a loss (without limit) as a result of a short sale if the market value of the borrowed security increases between the date of the short sale and the date the Fund replaces the security. The Fund may be unable to repurchase the borrowed security at a particular time or at an acceptable price.

▪ Interest Rate Risk — The value of fixed-income securities generally decreases in periods when interest rates are rising. In addition, interest rate changes typically have a greater effect on prices of longer-term fixed-income securities than shorter-term fixed-income securities.

▪ Credit Risk — An issuer of a fixed-income security could be downgraded or default. If the Fund holds securities that have been downgraded, or that default on payment, the Fund's performance could be negatively affected.

▪ High Yield Risk — High yield securities and unrated securities of similar credit quality (commonly known as "junk bonds") are subject to greater levels of credit and liquidity risks. High yield securities are considered primarily speculative with respect to the issuer's continuing ability to make principal and interest payments.

▪ Liquidity Risk — Liquidity risk exists when particular investments are difficult to purchase or sell. The Fund's investments in illiquid securities may reduce the returns of the Fund because it may be unable to sell the illiquid securities at an advantageous time or price.

▪ Portfolio Selection Risk — The value of your investment may decrease if the investment adviser's judgment about the attractiveness, value or market trends affecting a particular security, issuer, industry or sector or about market movements is incorrect.

▪ Portfolio Turnover Risk — The portfolio managers may actively and frequently trade securities or other instruments in the Fund's portfolio to carry out its investment strategies. A high portfolio turnover rate increases transaction costs, which may increase the Fund's expenses. Frequent and active trading may also cause adverse tax consequences for investors in the Fund due to an increase in short-term capital gains. 

The Principal Investment Strategies section for Growth and Income Fund on page 39 of the Class A, B and C Prospectus, and on page 32 of the Class I and R prospectus shall be replaced in its entirety as follows:

Principal Investment Strategies

The Fund invests primarily in a diversified portfolio of convertible, equity and fixed-income securities of U.S. companies without regard to market capitalization. In pursuing its investment objective, the Fund attempts to utilize these different types of securities to strike, in the investment adviser's opinion, the appropriate balance between risk and reward in terms of growth and income.

The Fund attempts to keep a consistent balance between risk and reward over the course of different market cycles, through various combinations of stocks, bonds and/or convertible securities, to achieve what the Fund's investment adviser believes to be an appropriate blend for the then-current market. As the market environment changes, portfolio securities may change in an attempt to achieve a relatively consistent risk level over time. At some points in a market cycle, one type of security may make up a substantial portion of the portfolio, while at other times certain securities may have minimal or no representation, depending on market conditions. The average term to maturity of the convertible and fixed-income securities purchased by the Fund will typically range from two to ten years. Interest rate changes normally have a greater effect on prices of longer-term bonds than shorter-term bonds. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser attempts to lower market risk by selecting and investing in securities that it believes will exhibit less volatility and will provide greater capital exposure and more consistent returns than the market as a whole.

The Principal Investment Strategies section for Global Growth and Income Fund on page 44 of the Class A, B and C Prospectus, and on page 37 of the Class I and R prospectus shall be replaced in its entirety as follows:

Principal Investment Strategies

The Fund invests primarily in a globally-diversified portfolio of convertible, equity and fixed-income securities without regard to market capitalization. In pursuing its investment objective, the Fund attempts to utilize these different types of securities to strike, in the investment adviser's opinion, the appropriate balance between risk and reward in terms of growth and income.

The Fund anticipates that under normal circumstances its investment adviser's investment process will result in the Fund investing in an internationally-diversified manner, with at least 40% of its assets in securities of foreign issuers. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser attempts to lower market risk by selecting and investing in securities that it believes will exhibit less volatility and will provide greater capital exposure and more consistent returns than the market as a whole.

The Principal Investment Strategies section for Convertible Fund on page 49 of the Class A, B and C Prospectus, and on page 41 of the Class I and R prospectus regarding shall be replaced in its entirety as follows:

Principal Investment Strategies

The Fund invests mainly in a diversified portfolio of convertible securities issued by both U.S. and foreign companies without regard to market capitalization. These convertible securities may be either debt securities or preferred stocks that can be exchanged for common stock. Under normal circumstances, the Fund invests at least 80% of its net assets (plus any borrowings) in convertible securities. The average term to maturity of the convertible securities purchased by the Fund will typically range from two to ten years.

The Fund may invest up to 25% of its net assets in foreign securities, but generally will invest approximately 5% to 15% of net assets in foreign securities.

In analyzing the appreciation potential of the underlying common stock and the default risk of the convertible security, the Fund generally considers the issuer's financial soundness, ability to make interest and dividend payments, earnings and cash flow forecast and quality of management. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser attempts to lower market risk by selecting and investing in securities that it believes will exhibit less volatility and will provide greater capital exposure and more consistent returns than the market as a whole.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

CALAMOS INVESTMENT TRUST/IL

Prospectus Date

rr_ProspectusDate

Feb. 29, 2012

Supplement [Text Block]

cit2_SupplementTextBlock

CALAMOS^® FAMILY OF FUNDS

Supplement dated December 19, 2012 to the

CALAMOS^® FAMILY OF FUNDS Prospectuses for

Class A, B, C and Class I and R dated February 29, 2012, as previously supplemented on

October 16, 2012, August 31, 2012, July 2, 2012, May 15, 2012 and March 30, 2012 and

the Statement of Additional Information dated February 29, 2012,

as previously supplemented on May 15, 2012

Effective January 2, 2013, the Principal Investment Strategies and Principal Risks sections for Market Neutral Income Fund on page 64 of the Class A, B and C Prospectus, and on page 54 of the Class I and R prospectus shall be replaced in their entirety as follows:

Principal Investment Strategies

The Fund's investment strategy can be characterized as "market neutral" because it seeks to achieve maximum current income while maintaining a low correlation to the fluctuations of the U.S. equity market as a whole. The Fund invests in (i) equities (ii) convertible securities of U.S. companies without regard to market capitalization and employs (iii) short selling to enhance income and hedge against market risk. The convertible securities in which the Fund invests may be either debt securities or preferred stocks that can be exchanged for common stock. The average term to maturity of the convertible securities purchased by the Fund will typically range from two to ten years.

The Fund may seek to generate income from option premiums by writing (selling) options. This would include the use of both call and put options. The Fund may write call options (i) on a portion of the equity securities (including securities that are convertible into equity securities) in the Fund's portfolio and (ii) on broad-based securities indexes (such as the S&P 500 or MSCI EAFE) or ETFs (exchange traded funds). In addition, to seek to offset some of the risk of a potential decline in value of certain long positions, the Fund may also purchase put options on individual securities, broad-based securities indexes (such as the S&P 500), or ETFs.

The Fund may invest without limit in high yield fixed-income securities (often referred to as "junk bonds"). In addition, the Fund may engage in active and frequent trading of portfolio securities. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes.

Principal Risks

An investment in the Fund is subject to risks, and you could lose money on your investment in the Fund. There can be no assurance that the Fund will achieve its investment objective. The risks associated with an investment in the Fund can increase during times of significant market volatility. Your 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. The principal risks of investing in the Fund include:

▪ Equity Securities Risk — The securities markets are volatile, and the market prices of the Fund's securities may decline generally. The price of equity securities fluctuates based on changes in a company's financial condition and overall market and economic conditions. If the market prices of the securities owned by the Fund fall, the value of your investment in the Fund will decline.

▪ Convertible Securities Risk — The value of a convertible security is influenced by changes in interest rates, with investment value declining as interest rates increase and increasing as interest rates decline. The credit standing of the issuer and other factors also may have an effect on the convertible security's investment value.

▪ Synthetic Convertible Instruments Risk — The value of a synthetic convertible instrument will respond differently to market fluctuations than a convertible security because a synthetic convertible instrument is composed of two or more separate securities, each with its own market value. In addition, if the value of the underlying common stock or the level of the index involved in the convertible component falls below the exercise price of the warrant or option, the warrant or option may lose all value.

▪ Convertible Hedging Risk — If the market price of the underlying common stock increases above the conversion price on a convertible security, the price of the convertible security will increase. The Fund's increased liability on any outstanding short position would, in whole or in part, reduce this gain.

▪ Covered Call Writing Risk — As the writer of a covered call option on a security, the Fund foregoes, during the option's life, the opportunity to profit from increases in the market value of the security, covering the call option above the sum of the premium and the exercise price of the call.

▪ Options Risk — The Fund's ability to close out its position as a purchaser or seller of an over-the-counter or exchange-listed put or call option is dependent, in part, upon the liquidity of the option market. There are significant differences between the securities and options markets that could result in an imperfect correlation among these markets, causing a given transaction not to achieve its objectives. The Fund's ability to utilize options successfully will depend on the ability of the Fund's investment adviser to predict pertinent market movements, which cannot be assured.

▪ Short Sale Risk — The Fund may incur a loss (without limit) as a result of a short sale if the market value of the borrowed security increases between the date of the short sale and the date the Fund replaces the security. The Fund may be unable to repurchase the borrowed security at a particular time or at an acceptable price.

▪ Interest Rate Risk — The value of fixed-income securities generally decreases in periods when interest rates are rising. In addition, interest rate changes typically have a greater effect on prices of longer-term fixed-income securities than shorter-term fixed-income securities.

▪ Credit Risk — An issuer of a fixed-income security could be downgraded or default. If the Fund holds securities that have been downgraded, or that default on payment, the Fund's performance could be negatively affected.

▪ High Yield Risk — High yield securities and unrated securities of similar credit quality (commonly known as "junk bonds") are subject to greater levels of credit and liquidity risks. High yield securities are considered primarily speculative with respect to the issuer's continuing ability to make principal and interest payments.

▪ Liquidity Risk — Liquidity risk exists when particular investments are difficult to purchase or sell. The Fund's investments in illiquid securities may reduce the returns of the Fund because it may be unable to sell the illiquid securities at an advantageous time or price.

▪ Portfolio Selection Risk — The value of your investment may decrease if the investment adviser's judgment about the attractiveness, value or market trends affecting a particular security, issuer, industry or sector or about market movements is incorrect.

▪ Portfolio Turnover Risk — The portfolio managers may actively and frequently trade securities or other instruments in the Fund's portfolio to carry out its investment strategies. A high portfolio turnover rate increases transaction costs, which may increase the Fund's expenses. Frequent and active trading may also cause adverse tax consequences for investors in the Fund due to an increase in short-term capital gains. 

The Principal Investment Strategies section for Growth and Income Fund on page 39 of the Class A, B and C Prospectus, and on page 32 of the Class I and R prospectus shall be replaced in its entirety as follows:

Principal Investment Strategies

The Fund invests primarily in a diversified portfolio of convertible, equity and fixed-income securities of U.S. companies without regard to market capitalization. In pursuing its investment objective, the Fund attempts to utilize these different types of securities to strike, in the investment adviser's opinion, the appropriate balance between risk and reward in terms of growth and income.

The Fund attempts to keep a consistent balance between risk and reward over the course of different market cycles, through various combinations of stocks, bonds and/or convertible securities, to achieve what the Fund's investment adviser believes to be an appropriate blend for the then-current market. As the market environment changes, portfolio securities may change in an attempt to achieve a relatively consistent risk level over time. At some points in a market cycle, one type of security may make up a substantial portion of the portfolio, while at other times certain securities may have minimal or no representation, depending on market conditions. The average term to maturity of the convertible and fixed-income securities purchased by the Fund will typically range from two to ten years. Interest rate changes normally have a greater effect on prices of longer-term bonds than shorter-term bonds. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser attempts to lower market risk by selecting and investing in securities that it believes will exhibit less volatility and will provide greater capital exposure and more consistent returns than the market as a whole.

The Principal Investment Strategies section for Global Growth and Income Fund on page 44 of the Class A, B and C Prospectus, and on page 37 of the Class I and R prospectus shall be replaced in its entirety as follows:

Principal Investment Strategies

The Fund invests primarily in a globally-diversified portfolio of convertible, equity and fixed-income securities without regard to market capitalization. In pursuing its investment objective, the Fund attempts to utilize these different types of securities to strike, in the investment adviser's opinion, the appropriate balance between risk and reward in terms of growth and income.

The Fund anticipates that under normal circumstances its investment adviser's investment process will result in the Fund investing in an internationally-diversified manner, with at least 40% of its assets in securities of foreign issuers. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser attempts to lower market risk by selecting and investing in securities that it believes will exhibit less volatility and will provide greater capital exposure and more consistent returns than the market as a whole.

The Principal Investment Strategies section for Convertible Fund on page 49 of the Class A, B and C Prospectus, and on page 41 of the Class I and R prospectus regarding shall be replaced in its entirety as follows:

Principal Investment Strategies

The Fund invests mainly in a diversified portfolio of convertible securities issued by both U.S. and foreign companies without regard to market capitalization. These convertible securities may be either debt securities or preferred stocks that can be exchanged for common stock. Under normal circumstances, the Fund invests at least 80% of its net assets (plus any borrowings) in convertible securities. The average term to maturity of the convertible securities purchased by the Fund will typically range from two to ten years.

The Fund may invest up to 25% of its net assets in foreign securities, but generally will invest approximately 5% to 15% of net assets in foreign securities.

In analyzing the appreciation potential of the underlying common stock and the default risk of the convertible security, the Fund generally considers the issuer's financial soundness, ability to make interest and dividend payments, earnings and cash flow forecast and quality of management. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser attempts to lower market risk by selecting and investing in securities that it believes will exhibit less volatility and will provide greater capital exposure and more consistent returns than the market as a whole.

Class A, B, and C Prospectus | Calamos Market Neutral Income Fund

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cit2_SupplementTextBlock

CALAMOS^® FAMILY OF FUNDS

Supplement dated December 19, 2012 to the

CALAMOS^® FAMILY OF FUNDS Prospectuses for

Class A, B, C and Class I and R dated February 29, 2012, as previously supplemented on

October 16, 2012, August 31, 2012, July 2, 2012, May 15, 2012 and March 30, 2012 and

the Statement of Additional Information dated February 29, 2012,

as previously supplemented on May 15, 2012

Effective January 2, 2013, the Principal Investment Strategies and Principal Risks sections for Market Neutral Income Fund on page 64 of the Class A, B and C Prospectus, and on page 54 of the Class I and R prospectus shall be replaced in their entirety as follows:

Principal Investment Strategies

The Fund's investment strategy can be characterized as "market neutral" because it seeks to achieve maximum current income while maintaining a low correlation to the fluctuations of the U.S. equity market as a whole. The Fund invests in (i) equities (ii) convertible securities of U.S. companies without regard to market capitalization and employs (iii) short selling to enhance income and hedge against market risk. The convertible securities in which the Fund invests may be either debt securities or preferred stocks that can be exchanged for common stock. The average term to maturity of the convertible securities purchased by the Fund will typically range from two to ten years.

The Fund may seek to generate income from option premiums by writing (selling) options. This would include the use of both call and put options. The Fund may write call options (i) on a portion of the equity securities (including securities that are convertible into equity securities) in the Fund's portfolio and (ii) on broad-based securities indexes (such as the S&P 500 or MSCI EAFE) or ETFs (exchange traded funds). In addition, to seek to offset some of the risk of a potential decline in value of certain long positions, the Fund may also purchase put options on individual securities, broad-based securities indexes (such as the S&P 500), or ETFs.

The Fund may invest without limit in high yield fixed-income securities (often referred to as "junk bonds"). In addition, the Fund may engage in active and frequent trading of portfolio securities. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes.

Principal Risks

An investment in the Fund is subject to risks, and you could lose money on your investment in the Fund. There can be no assurance that the Fund will achieve its investment objective. The risks associated with an investment in the Fund can increase during times of significant market volatility. Your 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. The principal risks of investing in the Fund include:

▪ Equity Securities Risk — The securities markets are volatile, and the market prices of the Fund's securities may decline generally. The price of equity securities fluctuates based on changes in a company's financial condition and overall market and economic conditions. If the market prices of the securities owned by the Fund fall, the value of your investment in the Fund will decline.

▪ Convertible Securities Risk — The value of a convertible security is influenced by changes in interest rates, with investment value declining as interest rates increase and increasing as interest rates decline. The credit standing of the issuer and other factors also may have an effect on the convertible security's investment value.

▪ Synthetic Convertible Instruments Risk — The value of a synthetic convertible instrument will respond differently to market fluctuations than a convertible security because a synthetic convertible instrument is composed of two or more separate securities, each with its own market value. In addition, if the value of the underlying common stock or the level of the index involved in the convertible component falls below the exercise price of the warrant or option, the warrant or option may lose all value.

▪ Convertible Hedging Risk — If the market price of the underlying common stock increases above the conversion price on a convertible security, the price of the convertible security will increase. The Fund's increased liability on any outstanding short position would, in whole or in part, reduce this gain.

▪ Covered Call Writing Risk — As the writer of a covered call option on a security, the Fund foregoes, during the option's life, the opportunity to profit from increases in the market value of the security, covering the call option above the sum of the premium and the exercise price of the call.

▪ Options Risk — The Fund's ability to close out its position as a purchaser or seller of an over-the-counter or exchange-listed put or call option is dependent, in part, upon the liquidity of the option market. There are significant differences between the securities and options markets that could result in an imperfect correlation among these markets, causing a given transaction not to achieve its objectives. The Fund's ability to utilize options successfully will depend on the ability of the Fund's investment adviser to predict pertinent market movements, which cannot be assured.

▪ Short Sale Risk — The Fund may incur a loss (without limit) as a result of a short sale if the market value of the borrowed security increases between the date of the short sale and the date the Fund replaces the security. The Fund may be unable to repurchase the borrowed security at a particular time or at an acceptable price.

▪ Interest Rate Risk — The value of fixed-income securities generally decreases in periods when interest rates are rising. In addition, interest rate changes typically have a greater effect on prices of longer-term fixed-income securities than shorter-term fixed-income securities.

▪ Credit Risk — An issuer of a fixed-income security could be downgraded or default. If the Fund holds securities that have been downgraded, or that default on payment, the Fund's performance could be negatively affected.

▪ High Yield Risk — High yield securities and unrated securities of similar credit quality (commonly known as "junk bonds") are subject to greater levels of credit and liquidity risks. High yield securities are considered primarily speculative with respect to the issuer's continuing ability to make principal and interest payments.

▪ Liquidity Risk — Liquidity risk exists when particular investments are difficult to purchase or sell. The Fund's investments in illiquid securities may reduce the returns of the Fund because it may be unable to sell the illiquid securities at an advantageous time or price.

▪ Portfolio Selection Risk — The value of your investment may decrease if the investment adviser's judgment about the attractiveness, value or market trends affecting a particular security, issuer, industry or sector or about market movements is incorrect.

▪ Portfolio Turnover Risk — The portfolio managers may actively and frequently trade securities or other instruments in the Fund's portfolio to carry out its investment strategies. A high portfolio turnover rate increases transaction costs, which may increase the Fund's expenses. Frequent and active trading may also cause adverse tax consequences for investors in the Fund due to an increase in short-term capital gains. 

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund's investment strategy can be characterized as "market neutral" because it seeks to achieve maximum current income while maintaining a low correlation to the fluctuations of the U.S. equity market as a whole. The Fund invests in (i) equities (ii) convertible securities of U.S. companies without regard to market capitalization and employs (iii) short selling to enhance income and hedge against market risk. The convertible securities in which the Fund invests may be either debt securities or preferred stocks that can be exchanged for common stock. The average term to maturity of the convertible securities purchased by the Fund will typically range from two to ten years.

The Fund may seek to generate income from option premiums by writing (selling) options. This would include the use of both call and put options. The Fund may write call options (i) on a portion of the equity securities (including securities that are convertible into equity securities) in the Fund's portfolio and (ii) on broad-based securities indexes (such as the S&P 500 or MSCI EAFE) or ETFs (exchange traded funds). In addition, to seek to offset some of the risk of a potential decline in value of certain long positions, the Fund may also purchase put options on individual securities, broad-based securities indexes (such as the S&P 500), or ETFs.

The Fund may invest without limit in high yield fixed-income securities (often referred to as "junk bonds"). In addition, the Fund may engage in active and frequent trading of portfolio securities. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes.

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

An investment in the Fund is subject to risks, and you could lose money on your investment in the Fund. There can be no assurance that the Fund will achieve its investment objective. The risks associated with an investment in the Fund can increase during times of significant market volatility. Your 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. The principal risks of investing in the Fund include:

▪ Equity Securities Risk — The securities markets are volatile, and the market prices of the Fund's securities may decline generally. The price of equity securities fluctuates based on changes in a company's financial condition and overall market and economic conditions. If the market prices of the securities owned by the Fund fall, the value of your investment in the Fund will decline.

▪ Convertible Securities Risk — The value of a convertible security is influenced by changes in interest rates, with investment value declining as interest rates increase and increasing as interest rates decline. The credit standing of the issuer and other factors also may have an effect on the convertible security's investment value.

▪ Synthetic Convertible Instruments Risk — The value of a synthetic convertible instrument will respond differently to market fluctuations than a convertible security because a synthetic convertible instrument is composed of two or more separate securities, each with its own market value. In addition, if the value of the underlying common stock or the level of the index involved in the convertible component falls below the exercise price of the warrant or option, the warrant or option may lose all value.

▪ Convertible Hedging Risk — If the market price of the underlying common stock increases above the conversion price on a convertible security, the price of the convertible security will increase. The Fund's increased liability on any outstanding short position would, in whole or in part, reduce this gain.

▪ Covered Call Writing Risk — As the writer of a covered call option on a security, the Fund foregoes, during the option's life, the opportunity to profit from increases in the market value of the security, covering the call option above the sum of the premium and the exercise price of the call.

▪ Options Risk — The Fund's ability to close out its position as a purchaser or seller of an over-the-counter or exchange-listed put or call option is dependent, in part, upon the liquidity of the option market. There are significant differences between the securities and options markets that could result in an imperfect correlation among these markets, causing a given transaction not to achieve its objectives. The Fund's ability to utilize options successfully will depend on the ability of the Fund's investment adviser to predict pertinent market movements, which cannot be assured.

▪ Short Sale Risk — The Fund may incur a loss (without limit) as a result of a short sale if the market value of the borrowed security increases between the date of the short sale and the date the Fund replaces the security. The Fund may be unable to repurchase the borrowed security at a particular time or at an acceptable price.

▪ Interest Rate Risk — The value of fixed-income securities generally decreases in periods when interest rates are rising. In addition, interest rate changes typically have a greater effect on prices of longer-term fixed-income securities than shorter-term fixed-income securities.

▪ Credit Risk — An issuer of a fixed-income security could be downgraded or default. If the Fund holds securities that have been downgraded, or that default on payment, the Fund's performance could be negatively affected.

▪ High Yield Risk — High yield securities and unrated securities of similar credit quality (commonly known as "junk bonds") are subject to greater levels of credit and liquidity risks. High yield securities are considered primarily speculative with respect to the issuer's continuing ability to make principal and interest payments.

▪ Liquidity Risk — Liquidity risk exists when particular investments are difficult to purchase or sell. The Fund's investments in illiquid securities may reduce the returns of the Fund because it may be unable to sell the illiquid securities at an advantageous time or price.

▪ Portfolio Selection Risk — The value of your investment may decrease if the investment adviser's judgment about the attractiveness, value or market trends affecting a particular security, issuer, industry or sector or about market movements is incorrect.

▪ Portfolio Turnover Risk — The portfolio managers may actively and frequently trade securities or other instruments in the Fund's portfolio to carry out its investment strategies. A high portfolio turnover rate increases transaction costs, which may increase the Fund's expenses. Frequent and active trading may also cause adverse tax consequences for investors in the Fund due to an increase in short-term capital gains. 

Risk Lose Money [Text]

rr_RiskLoseMoney

An investment in the Fund is subject to risks, and you could lose money on your investment in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

Your 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.

Class A, B, and C Prospectus | Calamos Growth & Income Fund

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cit2_SupplementTextBlock

CALAMOS^® FAMILY OF FUNDS

Supplement dated December 19, 2012 to the

CALAMOS^® FAMILY OF FUNDS Prospectuses for

Class A, B, C and Class I and R dated February 29, 2012, as previously supplemented on

October 16, 2012, August 31, 2012, July 2, 2012, May 15, 2012 and March 30, 2012 and

the Statement of Additional Information dated February 29, 2012,

as previously supplemented on May 15, 2012

The Principal Investment Strategies section for Growth and Income Fund on page 39 of the Class A, B and C Prospectus, and on page 32 of the Class I and R prospectus shall be replaced in its entirety as follows:

Principal Investment Strategies

The Fund invests primarily in a diversified portfolio of convertible, equity and fixed-income securities of U.S. companies without regard to market capitalization. In pursuing its investment objective, the Fund attempts to utilize these different types of securities to strike, in the investment adviser's opinion, the appropriate balance between risk and reward in terms of growth and income.

The Fund attempts to keep a consistent balance between risk and reward over the course of different market cycles, through various combinations of stocks, bonds and/or convertible securities, to achieve what the Fund's investment adviser believes to be an appropriate blend for the then-current market. As the market environment changes, portfolio securities may change in an attempt to achieve a relatively consistent risk level over time. At some points in a market cycle, one type of security may make up a substantial portion of the portfolio, while at other times certain securities may have minimal or no representation, depending on market conditions. The average term to maturity of the convertible and fixed-income securities purchased by the Fund will typically range from two to ten years. Interest rate changes normally have a greater effect on prices of longer-term bonds than shorter-term bonds. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser attempts to lower market risk by selecting and investing in securities that it believes will exhibit less volatility and will provide greater capital exposure and more consistent returns than the market as a whole.

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in a diversified portfolio of convertible, equity and fixed-income securities of U.S. companies without regard to market capitalization. In pursuing its investment objective, the Fund attempts to utilize these different types of securities to strike, in the investment adviser's opinion, the appropriate balance between risk and reward in terms of growth and income.

The Fund attempts to keep a consistent balance between risk and reward over the course of different market cycles, through various combinations of stocks, bonds and/or convertible securities, to achieve what the Fund's investment adviser believes to be an appropriate blend for the then-current market. As the market environment changes, portfolio securities may change in an attempt to achieve a relatively consistent risk level over time. At some points in a market cycle, one type of security may make up a substantial portion of the portfolio, while at other times certain securities may have minimal or no representation, depending on market conditions. The average term to maturity of the convertible and fixed-income securities purchased by the Fund will typically range from two to ten years. Interest rate changes normally have a greater effect on prices of longer-term bonds than shorter-term bonds. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser attempts to lower market risk by selecting and investing in securities that it believes will exhibit less volatility and will provide greater capital exposure and more consistent returns than the market as a whole.

Class A, B, and C Prospectus | Calamos Global Growth & Income Fund

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cit2_SupplementTextBlock

CALAMOS^® FAMILY OF FUNDS

Supplement dated December 19, 2012 to the

CALAMOS^® FAMILY OF FUNDS Prospectuses for

Class A, B, C and Class I and R dated February 29, 2012, as previously supplemented on

October 16, 2012, August 31, 2012, July 2, 2012, May 15, 2012 and March 30, 2012 and

the Statement of Additional Information dated February 29, 2012,

as previously supplemented on May 15, 2012

The Principal Investment Strategies section for Global Growth and Income Fund on page 44 of the Class A, B and C Prospectus, and on page 37 of the Class I and R prospectus shall be replaced in its entirety as follows:

Principal Investment Strategies

The Fund invests primarily in a globally-diversified portfolio of convertible, equity and fixed-income securities without regard to market capitalization. In pursuing its investment objective, the Fund attempts to utilize these different types of securities to strike, in the investment adviser's opinion, the appropriate balance between risk and reward in terms of growth and income.

The Fund anticipates that under normal circumstances its investment adviser's investment process will result in the Fund investing in an internationally-diversified manner, with at least 40% of its assets in securities of foreign issuers. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser attempts to lower market risk by selecting and investing in securities that it believes will exhibit less volatility and will provide greater capital exposure and more consistent returns than the market as a whole.

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in a globally-diversified portfolio of convertible, equity and fixed-income securities without regard to market capitalization. In pursuing its investment objective, the Fund attempts to utilize these different types of securities to strike, in the investment adviser's opinion, the appropriate balance between risk and reward in terms of growth and income.

The Fund anticipates that under normal circumstances its investment adviser's investment process will result in the Fund investing in an internationally-diversified manner, with at least 40% of its assets in securities of foreign issuers. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser attempts to lower market risk by selecting and investing in securities that it believes will exhibit less volatility and will provide greater capital exposure and more consistent returns than the market as a whole.

Class A, B, and C Prospectus | Calamos Convertible Fund

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cit2_SupplementTextBlock

CALAMOS^® FAMILY OF FUNDS

Supplement dated December 19, 2012 to the

CALAMOS^® FAMILY OF FUNDS Prospectuses for

Class A, B, C and Class I and R dated February 29, 2012, as previously supplemented on

October 16, 2012, August 31, 2012, July 2, 2012, May 15, 2012 and March 30, 2012 and

the Statement of Additional Information dated February 29, 2012,

as previously supplemented on May 15, 2012

The Principal Investment Strategies section for Convertible Fund on page 49 of the Class A, B and C Prospectus, and on page 41 of the Class I and R prospectus regarding shall be replaced in its entirety as follows:

Principal Investment Strategies

The Fund invests mainly in a diversified portfolio of convertible securities issued by both U.S. and foreign companies without regard to market capitalization. These convertible securities may be either debt securities or preferred stocks that can be exchanged for common stock. Under normal circumstances, the Fund invests at least 80% of its net assets (plus any borrowings) in convertible securities. The average term to maturity of the convertible securities purchased by the Fund will typically range from two to ten years.

The Fund may invest up to 25% of its net assets in foreign securities, but generally will invest approximately 5% to 15% of net assets in foreign securities.

In analyzing the appreciation potential of the underlying common stock and the default risk of the convertible security, the Fund generally considers the issuer's financial soundness, ability to make interest and dividend payments, earnings and cash flow forecast and quality of management. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser attempts to lower market risk by selecting and investing in securities that it believes will exhibit less volatility and will provide greater capital exposure and more consistent returns than the market as a whole.

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests mainly in a diversified portfolio of convertible securities issued by both U.S. and foreign companies without regard to market capitalization. These convertible securities may be either debt securities or preferred stocks that can be exchanged for common stock. Under normal circumstances, the Fund invests at least 80% of its net assets (plus any borrowings) in convertible securities. The average term to maturity of the convertible securities purchased by the Fund will typically range from two to ten years.

The Fund may invest up to 25% of its net assets in foreign securities, but generally will invest approximately 5% to 15% of net assets in foreign securities.

In analyzing the appreciation potential of the underlying common stock and the default risk of the convertible security, the Fund generally considers the issuer's financial soundness, ability to make interest and dividend payments, earnings and cash flow forecast and quality of management. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser attempts to lower market risk by selecting and investing in securities that it believes will exhibit less volatility and will provide greater capital exposure and more consistent returns than the market as a whole.

Class I and R Prospectus | Calamos Market Neutral Income Fund

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cit2_SupplementTextBlock

CALAMOS^® FAMILY OF FUNDS

Supplement dated December 19, 2012 to the

CALAMOS^® FAMILY OF FUNDS Prospectuses for

Class A, B, C and Class I and R dated February 29, 2012, as previously supplemented on

October 16, 2012, August 31, 2012, July 2, 2012, May 15, 2012 and March 30, 2012 and

the Statement of Additional Information dated February 29, 2012,

as previously supplemented on May 15, 2012

Effective January 2, 2013, the Principal Investment Strategies and Principal Risks sections for Market Neutral Income Fund on page 64 of the Class A, B and C Prospectus, and on page 54 of the Class I and R prospectus shall be replaced in their entirety as follows:

Principal Investment Strategies

The Fund's investment strategy can be characterized as "market neutral" because it seeks to achieve maximum current income while maintaining a low correlation to the fluctuations of the U.S. equity market as a whole. The Fund invests in (i) equities (ii) convertible securities of U.S. companies without regard to market capitalization and employs (iii) short selling to enhance income and hedge against market risk. The convertible securities in which the Fund invests may be either debt securities or preferred stocks that can be exchanged for common stock. The average term to maturity of the convertible securities purchased by the Fund will typically range from two to ten years.

The Fund may seek to generate income from option premiums by writing (selling) options. This would include the use of both call and put options. The Fund may write call options (i) on a portion of the equity securities (including securities that are convertible into equity securities) in the Fund's portfolio and (ii) on broad-based securities indexes (such as the S&P 500 or MSCI EAFE) or ETFs (exchange traded funds). In addition, to seek to offset some of the risk of a potential decline in value of certain long positions, the Fund may also purchase put options on individual securities, broad-based securities indexes (such as the S&P 500), or ETFs.

The Fund may invest without limit in high yield fixed-income securities (often referred to as "junk bonds"). In addition, the Fund may engage in active and frequent trading of portfolio securities. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes.

Principal Risks

An investment in the Fund is subject to risks, and you could lose money on your investment in the Fund. There can be no assurance that the Fund will achieve its investment objective. The risks associated with an investment in the Fund can increase during times of significant market volatility. Your 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. The principal risks of investing in the Fund include:

▪ Equity Securities Risk — The securities markets are volatile, and the market prices of the Fund's securities may decline generally. The price of equity securities fluctuates based on changes in a company's financial condition and overall market and economic conditions. If the market prices of the securities owned by the Fund fall, the value of your investment in the Fund will decline.

▪ Convertible Securities Risk — The value of a convertible security is influenced by changes in interest rates, with investment value declining as interest rates increase and increasing as interest rates decline. The credit standing of the issuer and other factors also may have an effect on the convertible security's investment value.

▪ Synthetic Convertible Instruments Risk — The value of a synthetic convertible instrument will respond differently to market fluctuations than a convertible security because a synthetic convertible instrument is composed of two or more separate securities, each with its own market value. In addition, if the value of the underlying common stock or the level of the index involved in the convertible component falls below the exercise price of the warrant or option, the warrant or option may lose all value.

▪ Convertible Hedging Risk — If the market price of the underlying common stock increases above the conversion price on a convertible security, the price of the convertible security will increase. The Fund's increased liability on any outstanding short position would, in whole or in part, reduce this gain.

▪ Covered Call Writing Risk — As the writer of a covered call option on a security, the Fund foregoes, during the option's life, the opportunity to profit from increases in the market value of the security, covering the call option above the sum of the premium and the exercise price of the call.

▪ Options Risk — The Fund's ability to close out its position as a purchaser or seller of an over-the-counter or exchange-listed put or call option is dependent, in part, upon the liquidity of the option market. There are significant differences between the securities and options markets that could result in an imperfect correlation among these markets, causing a given transaction not to achieve its objectives. The Fund's ability to utilize options successfully will depend on the ability of the Fund's investment adviser to predict pertinent market movements, which cannot be assured.

▪ Short Sale Risk — The Fund may incur a loss (without limit) as a result of a short sale if the market value of the borrowed security increases between the date of the short sale and the date the Fund replaces the security. The Fund may be unable to repurchase the borrowed security at a particular time or at an acceptable price.

▪ Interest Rate Risk — The value of fixed-income securities generally decreases in periods when interest rates are rising. In addition, interest rate changes typically have a greater effect on prices of longer-term fixed-income securities than shorter-term fixed-income securities.

▪ Credit Risk — An issuer of a fixed-income security could be downgraded or default. If the Fund holds securities that have been downgraded, or that default on payment, the Fund's performance could be negatively affected.

▪ High Yield Risk — High yield securities and unrated securities of similar credit quality (commonly known as "junk bonds") are subject to greater levels of credit and liquidity risks. High yield securities are considered primarily speculative with respect to the issuer's continuing ability to make principal and interest payments.

▪ Liquidity Risk — Liquidity risk exists when particular investments are difficult to purchase or sell. The Fund's investments in illiquid securities may reduce the returns of the Fund because it may be unable to sell the illiquid securities at an advantageous time or price.

▪ Portfolio Selection Risk — The value of your investment may decrease if the investment adviser's judgment about the attractiveness, value or market trends affecting a particular security, issuer, industry or sector or about market movements is incorrect.

▪ Portfolio Turnover Risk — The portfolio managers may actively and frequently trade securities or other instruments in the Fund's portfolio to carry out its investment strategies. A high portfolio turnover rate increases transaction costs, which may increase the Fund's expenses. Frequent and active trading may also cause adverse tax consequences for investors in the Fund due to an increase in short-term capital gains. 

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund's investment strategy can be characterized as "market neutral" because it seeks to achieve maximum current income while maintaining a low correlation to the fluctuations of the U.S. equity market as a whole. The Fund invests in (i) equities (ii) convertible securities of U.S. companies without regard to market capitalization and employs (iii) short selling to enhance income and hedge against market risk. The convertible securities in which the Fund invests may be either debt securities or preferred stocks that can be exchanged for common stock. The average term to maturity of the convertible securities purchased by the Fund will typically range from two to ten years.

The Fund may seek to generate income from option premiums by writing (selling) options. This would include the use of both call and put options. The Fund may write call options (i) on a portion of the equity securities (including securities that are convertible into equity securities) in the Fund's portfolio and (ii) on broad-based securities indexes (such as the S&P 500 or MSCI EAFE) or ETFs (exchange traded funds). In addition, to seek to offset some of the risk of a potential decline in value of certain long positions, the Fund may also purchase put options on individual securities, broad-based securities indexes (such as the S&P 500), or ETFs.

The Fund may invest without limit in high yield fixed-income securities (often referred to as "junk bonds"). In addition, the Fund may engage in active and frequent trading of portfolio securities. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes.

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

An investment in the Fund is subject to risks, and you could lose money on your investment in the Fund. There can be no assurance that the Fund will achieve its investment objective. The risks associated with an investment in the Fund can increase during times of significant market volatility. Your 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. The principal risks of investing in the Fund include:

▪ Equity Securities Risk — The securities markets are volatile, and the market prices of the Fund's securities may decline generally. The price of equity securities fluctuates based on changes in a company's financial condition and overall market and economic conditions. If the market prices of the securities owned by the Fund fall, the value of your investment in the Fund will decline.

▪ Convertible Securities Risk — The value of a convertible security is influenced by changes in interest rates, with investment value declining as interest rates increase and increasing as interest rates decline. The credit standing of the issuer and other factors also may have an effect on the convertible security's investment value.

▪ Synthetic Convertible Instruments Risk — The value of a synthetic convertible instrument will respond differently to market fluctuations than a convertible security because a synthetic convertible instrument is composed of two or more separate securities, each with its own market value. In addition, if the value of the underlying common stock or the level of the index involved in the convertible component falls below the exercise price of the warrant or option, the warrant or option may lose all value.

▪ Convertible Hedging Risk — If the market price of the underlying common stock increases above the conversion price on a convertible security, the price of the convertible security will increase. The Fund's increased liability on any outstanding short position would, in whole or in part, reduce this gain.

▪ Covered Call Writing Risk — As the writer of a covered call option on a security, the Fund foregoes, during the option's life, the opportunity to profit from increases in the market value of the security, covering the call option above the sum of the premium and the exercise price of the call.

▪ Options Risk — The Fund's ability to close out its position as a purchaser or seller of an over-the-counter or exchange-listed put or call option is dependent, in part, upon the liquidity of the option market. There are significant differences between the securities and options markets that could result in an imperfect correlation among these markets, causing a given transaction not to achieve its objectives. The Fund's ability to utilize options successfully will depend on the ability of the Fund's investment adviser to predict pertinent market movements, which cannot be assured.

▪ Short Sale Risk — The Fund may incur a loss (without limit) as a result of a short sale if the market value of the borrowed security increases between the date of the short sale and the date the Fund replaces the security. The Fund may be unable to repurchase the borrowed security at a particular time or at an acceptable price.

▪ Interest Rate Risk — The value of fixed-income securities generally decreases in periods when interest rates are rising. In addition, interest rate changes typically have a greater effect on prices of longer-term fixed-income securities than shorter-term fixed-income securities.

▪ Credit Risk — An issuer of a fixed-income security could be downgraded or default. If the Fund holds securities that have been downgraded, or that default on payment, the Fund's performance could be negatively affected.

▪ High Yield Risk — High yield securities and unrated securities of similar credit quality (commonly known as "junk bonds") are subject to greater levels of credit and liquidity risks. High yield securities are considered primarily speculative with respect to the issuer's continuing ability to make principal and interest payments.

▪ Liquidity Risk — Liquidity risk exists when particular investments are difficult to purchase or sell. The Fund's investments in illiquid securities may reduce the returns of the Fund because it may be unable to sell the illiquid securities at an advantageous time or price.

▪ Portfolio Selection Risk — The value of your investment may decrease if the investment adviser's judgment about the attractiveness, value or market trends affecting a particular security, issuer, industry or sector or about market movements is incorrect.

▪ Portfolio Turnover Risk — The portfolio managers may actively and frequently trade securities or other instruments in the Fund's portfolio to carry out its investment strategies. A high portfolio turnover rate increases transaction costs, which may increase the Fund's expenses. Frequent and active trading may also cause adverse tax consequences for investors in the Fund due to an increase in short-term capital gains. 

Risk Lose Money [Text]

rr_RiskLoseMoney

An investment in the Fund is subject to risks, and you could lose money on your investment in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

Your 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.

Class I and R Prospectus | Calamos Growth & Income Fund

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cit2_SupplementTextBlock

CALAMOS^® FAMILY OF FUNDS

Supplement dated December 19, 2012 to the

CALAMOS^® FAMILY OF FUNDS Prospectuses for

Class A, B, C and Class I and R dated February 29, 2012, as previously supplemented on

October 16, 2012, August 31, 2012, July 2, 2012, May 15, 2012 and March 30, 2012 and

the Statement of Additional Information dated February 29, 2012,

as previously supplemented on May 15, 2012

The Principal Investment Strategies section for Growth and Income Fund on page 39 of the Class A, B and C Prospectus, and on page 32 of the Class I and R prospectus shall be replaced in its entirety as follows:

Principal Investment Strategies

The Fund invests primarily in a diversified portfolio of convertible, equity and fixed-income securities of U.S. companies without regard to market capitalization. In pursuing its investment objective, the Fund attempts to utilize these different types of securities to strike, in the investment adviser's opinion, the appropriate balance between risk and reward in terms of growth and income.

The Fund attempts to keep a consistent balance between risk and reward over the course of different market cycles, through various combinations of stocks, bonds and/or convertible securities, to achieve what the Fund's investment adviser believes to be an appropriate blend for the then-current market. As the market environment changes, portfolio securities may change in an attempt to achieve a relatively consistent risk level over time. At some points in a market cycle, one type of security may make up a substantial portion of the portfolio, while at other times certain securities may have minimal or no representation, depending on market conditions. The average term to maturity of the convertible and fixed-income securities purchased by the Fund will typically range from two to ten years. Interest rate changes normally have a greater effect on prices of longer-term bonds than shorter-term bonds. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser attempts to lower market risk by selecting and investing in securities that it believes will exhibit less volatility and will provide greater capital exposure and more consistent returns than the market as a whole.

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in a diversified portfolio of convertible, equity and fixed-income securities of U.S. companies without regard to market capitalization. In pursuing its investment objective, the Fund attempts to utilize these different types of securities to strike, in the investment adviser's opinion, the appropriate balance between risk and reward in terms of growth and income.

The Fund attempts to keep a consistent balance between risk and reward over the course of different market cycles, through various combinations of stocks, bonds and/or convertible securities, to achieve what the Fund's investment adviser believes to be an appropriate blend for the then-current market. As the market environment changes, portfolio securities may change in an attempt to achieve a relatively consistent risk level over time. At some points in a market cycle, one type of security may make up a substantial portion of the portfolio, while at other times certain securities may have minimal or no representation, depending on market conditions. The average term to maturity of the convertible and fixed-income securities purchased by the Fund will typically range from two to ten years. Interest rate changes normally have a greater effect on prices of longer-term bonds than shorter-term bonds. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser attempts to lower market risk by selecting and investing in securities that it believes will exhibit less volatility and will provide greater capital exposure and more consistent returns than the market as a whole.

Class I and R Prospectus | Calamos Global Growth & Income Fund

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cit2_SupplementTextBlock

CALAMOS^® FAMILY OF FUNDS

Supplement dated December 19, 2012 to the

CALAMOS^® FAMILY OF FUNDS Prospectuses for

Class A, B, C and Class I and R dated February 29, 2012, as previously supplemented on

October 16, 2012, August 31, 2012, July 2, 2012, May 15, 2012 and March 30, 2012 and

the Statement of Additional Information dated February 29, 2012,

as previously supplemented on May 15, 2012

The Principal Investment Strategies section for Global Growth and Income Fund on page 44 of the Class A, B and C Prospectus, and on page 37 of the Class I and R prospectus shall be replaced in its entirety as follows:

Principal Investment Strategies

The Fund invests primarily in a globally-diversified portfolio of convertible, equity and fixed-income securities without regard to market capitalization. In pursuing its investment objective, the Fund attempts to utilize these different types of securities to strike, in the investment adviser's opinion, the appropriate balance between risk and reward in terms of growth and income.

The Fund anticipates that under normal circumstances its investment adviser's investment process will result in the Fund investing in an internationally-diversified manner, with at least 40% of its assets in securities of foreign issuers. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser attempts to lower market risk by selecting and investing in securities that it believes will exhibit less volatility and will provide greater capital exposure and more consistent returns than the market as a whole.

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in a globally-diversified portfolio of convertible, equity and fixed-income securities without regard to market capitalization. In pursuing its investment objective, the Fund attempts to utilize these different types of securities to strike, in the investment adviser's opinion, the appropriate balance between risk and reward in terms of growth and income.

The Fund anticipates that under normal circumstances its investment adviser's investment process will result in the Fund investing in an internationally-diversified manner, with at least 40% of its assets in securities of foreign issuers. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser attempts to lower market risk by selecting and investing in securities that it believes will exhibit less volatility and will provide greater capital exposure and more consistent returns than the market as a whole.

Class I and R Prospectus | Calamos Convertible Fund

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cit2_SupplementTextBlock

CALAMOS^® FAMILY OF FUNDS

Supplement dated December 19, 2012 to the

CALAMOS^® FAMILY OF FUNDS Prospectuses for

Class A, B, C and Class I and R dated February 29, 2012, as previously supplemented on

October 16, 2012, August 31, 2012, July 2, 2012, May 15, 2012 and March 30, 2012 and

the Statement of Additional Information dated February 29, 2012,

as previously supplemented on May 15, 2012

The Principal Investment Strategies section for Convertible Fund on page 49 of the Class A, B and C Prospectus, and on page 41 of the Class I and R prospectus regarding shall be replaced in its entirety as follows:

Principal Investment Strategies

The Fund invests mainly in a diversified portfolio of convertible securities issued by both U.S. and foreign companies without regard to market capitalization. These convertible securities may be either debt securities or preferred stocks that can be exchanged for common stock. Under normal circumstances, the Fund invests at least 80% of its net assets (plus any borrowings) in convertible securities. The average term to maturity of the convertible securities purchased by the Fund will typically range from two to ten years.

The Fund may invest up to 25% of its net assets in foreign securities, but generally will invest approximately 5% to 15% of net assets in foreign securities.

In analyzing the appreciation potential of the underlying common stock and the default risk of the convertible security, the Fund generally considers the issuer's financial soundness, ability to make interest and dividend payments, earnings and cash flow forecast and quality of management. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser attempts to lower market risk by selecting and investing in securities that it believes will exhibit less volatility and will provide greater capital exposure and more consistent returns than the market as a whole.

Strategy [Heading]

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Principal Investment Strategies

Strategy Narrative [Text Block]

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The Fund invests mainly in a diversified portfolio of convertible securities issued by both U.S. and foreign companies without regard to market capitalization. These convertible securities may be either debt securities or preferred stocks that can be exchanged for common stock. Under normal circumstances, the Fund invests at least 80% of its net assets (plus any borrowings) in convertible securities. The average term to maturity of the convertible securities purchased by the Fund will typically range from two to ten years.

The Fund may invest up to 25% of its net assets in foreign securities, but generally will invest approximately 5% to 15% of net assets in foreign securities.

In analyzing the appreciation potential of the underlying common stock and the default risk of the convertible security, the Fund generally considers the issuer's financial soundness, ability to make interest and dividend payments, earnings and cash flow forecast and quality of management. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser attempts to lower market risk by selecting and investing in securities that it believes will exhibit less volatility and will provide greater capital exposure and more consistent returns than the market as a whole.

XML

Document and Entity Information	12 Months Ended
	Feb. 29, 2012
Risk/Return:
Document Type	Other
Document Period End Date	Oct. 31, 2011
Registrant Name	CALAMOS INVESTMENT TRUST/IL
Central Index Key	0000826732
Amendment Flag	false
Document Creation Date	Dec. 19, 2012
Document Effective Date	Dec. 19, 2012
Prospectus Date	Feb. 29, 2012

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	CALAMOS INVESTMENT TRUST/IL
Prospectus Date	rr_ProspectusDate	Feb. 29, 2012
Document Creation Date	dei_DocumentCreationDate	Dec. 19, 2012