Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	CALVERT FUND
Prospectus Date	rr_ProspectusDate	Jan. 31, 2012
Supplement [Text Block]	cf2_SupplementTextBlock	SUPPLEMENT TO CALVERT INCOME FUNDS PROSPECTUS (CLASS A, B, C, O AND Y) DATED JANUARY 31, 2012, AS REVISED APRIL 27, 2012 Calvert Income Fund Calvert Short Duration Income Fund Calvert Long-Term Income Fund Calvert Ultra-Short Income Fund Calvert Government Fund Calvert High Yield Bond Fund CALVERT INCOME FUNDS PROSPECTUS (CLASS I) DATED JANUARY 31, 2012 Calvert Income Fund Calvert Short Duration Income Fund Calvert Government Fund Calvert High Yield Bond Fund Date of Supplement: November 1, 2012 After the last paragraph in the section “Investments, Risks and Performance – Principal Investment Strategies” in each Fund Summary (Portfolio Summary for Calvert VP Income Portfolio), insert the following: Tobacco Exclusion. The Fund seeks to avoid investing in companies classified under the tobacco industry sector of the Barclays Global Aggregate Index, the Barclays U.S. High Yield Index or the Barclays Global Emerging Market Index; or, in the opinion of the Fund’s Advisor, any similar securities in the Barclays Municipal Index.
Retail \| Calvert Income Fund
Risk/Return:	rr_RiskReturnAbstract
Supplement [Text Block]	cf2_SupplementTextBlock	SUPPLEMENT TO CALVERT INCOME FUNDS PROSPECTUS (CLASS A, B, C, O AND Y) DATED JANUARY 31, 2012, AS REVISED APRIL 27, 2012 Calvert Income Fund Calvert Short Duration Income Fund Calvert Long-Term Income Fund Calvert Ultra-Short Income Fund Calvert Government Fund Calvert High Yield Bond Fund Date of Supplement: November 1, 2012 After the last paragraph in the section “Investments, Risks and Performance – Principal Investment Strategies” in each Fund Summary (Portfolio Summary for Calvert VP Income Portfolio), insert the following: Tobacco Exclusion. The Fund seeks to avoid investing in companies classified under the tobacco industry sector of the Barclays Global Aggregate Index, the Barclays U.S. High Yield Index or the Barclays Global Emerging Market Index; or, in the opinion of the Fund’s Advisor, any similar securities in the Barclays Municipal Index.
Retail \| Calvert Short Duration Income Fund
Risk/Return:	rr_RiskReturnAbstract
Supplement [Text Block]	cf2_SupplementTextBlock	SUPPLEMENT TO CALVERT INCOME FUNDS PROSPECTUS (CLASS A, B, C, O AND Y) DATED JANUARY 31, 2012, AS REVISED APRIL 27, 2012 Calvert Income Fund Calvert Short Duration Income Fund Calvert Long-Term Income Fund Calvert Ultra-Short Income Fund Calvert Government Fund Calvert High Yield Bond Fund Date of Supplement: November 1, 2012 After the last paragraph in the section “Investments, Risks and Performance – Principal Investment Strategies” in each Fund Summary (Portfolio Summary for Calvert VP Income Portfolio), insert the following: Tobacco Exclusion. The Fund seeks to avoid investing in companies classified under the tobacco industry sector of the Barclays Global Aggregate Index, the Barclays U.S. High Yield Index or the Barclays Global Emerging Market Index; or, in the opinion of the Fund’s Advisor, any similar securities in the Barclays Municipal Index.
Retail \| Calvert Long-Term Income Fund
Risk/Return:	rr_RiskReturnAbstract
Supplement [Text Block]	cf2_SupplementTextBlock	SUPPLEMENT TO CALVERT INCOME FUNDS PROSPECTUS (CLASS A, B, C, O AND Y) DATED JANUARY 31, 2012, AS REVISED APRIL 27, 2012 Calvert Income Fund Calvert Short Duration Income Fund Calvert Long-Term Income Fund Calvert Ultra-Short Income Fund Calvert Government Fund Calvert High Yield Bond Fund Date of Supplement: November 1, 2012 After the last paragraph in the section “Investments, Risks and Performance – Principal Investment Strategies” in each Fund Summary (Portfolio Summary for Calvert VP Income Portfolio), insert the following: Tobacco Exclusion. The Fund seeks to avoid investing in companies classified under the tobacco industry sector of the Barclays Global Aggregate Index, the Barclays U.S. High Yield Index or the Barclays Global Emerging Market Index; or, in the opinion of the Fund’s Advisor, any similar securities in the Barclays Municipal Index.
Retail \| Calvert Ultra-Short Income Fund
Risk/Return:	rr_RiskReturnAbstract
Supplement [Text Block]	cf2_SupplementTextBlock	SUPPLEMENT TO CALVERT INCOME FUNDS PROSPECTUS (CLASS A, B, C, O AND Y) DATED JANUARY 31, 2012, AS REVISED APRIL 27, 2012 Calvert Income Fund Calvert Short Duration Income Fund Calvert Long-Term Income Fund Calvert Ultra-Short Income Fund Calvert Government Fund Calvert High Yield Bond Fund Date of Supplement: November 1, 2012 After the last paragraph in the section “Investments, Risks and Performance – Principal Investment Strategies” in each Fund Summary (Portfolio Summary for Calvert VP Income Portfolio), insert the following: Tobacco Exclusion. The Fund seeks to avoid investing in companies classified under the tobacco industry sector of the Barclays Global Aggregate Index, the Barclays U.S. High Yield Index or the Barclays Global Emerging Market Index; or, in the opinion of the Fund’s Advisor, any similar securities in the Barclays Municipal Index.
Retail \| Calvert Government Fund
Risk/Return:	rr_RiskReturnAbstract
Supplement [Text Block]	cf2_SupplementTextBlock	SUPPLEMENT TO CALVERT INCOME FUNDS PROSPECTUS (CLASS A, B, C, O AND Y) DATED JANUARY 31, 2012, AS REVISED APRIL 27, 2012 Calvert Income Fund Calvert Short Duration Income Fund Calvert Long-Term Income Fund Calvert Ultra-Short Income Fund Calvert Government Fund Calvert High Yield Bond Fund Date of Supplement: November 1, 2012 After the last paragraph in the section “Investments, Risks and Performance – Principal Investment Strategies” in each Fund Summary (Portfolio Summary for Calvert VP Income Portfolio), insert the following: Tobacco Exclusion. The Fund seeks to avoid investing in companies classified under the tobacco industry sector of the Barclays Global Aggregate Index, the Barclays U.S. High Yield Index or the Barclays Global Emerging Market Index; or, in the opinion of the Fund’s Advisor, any similar securities in the Barclays Municipal Index.
Retail \| Calvert High Yield Bond Fund
Risk/Return:	rr_RiskReturnAbstract
Supplement [Text Block]	cf2_SupplementTextBlock	SUPPLEMENT TO CALVERT INCOME FUNDS PROSPECTUS (CLASS A, B, C, O AND Y) DATED JANUARY 31, 2012, AS REVISED APRIL 27, 2012 Calvert Income Fund Calvert Short Duration Income Fund Calvert Long-Term Income Fund Calvert Ultra-Short Income Fund Calvert Government Fund Calvert High Yield Bond Fund Date of Supplement: November 1, 2012 After the last paragraph in the section “Investments, Risks and Performance – Principal Investment Strategies” in each Fund Summary (Portfolio Summary for Calvert VP Income Portfolio), insert the following: Tobacco Exclusion. The Fund seeks to avoid investing in companies classified under the tobacco industry sector of the Barclays Global Aggregate Index, the Barclays U.S. High Yield Index or the Barclays Global Emerging Market Index; or, in the opinion of the Fund’s Advisor, any similar securities in the Barclays Municipal Index.
Institutional \| Calvert Income Fund
Risk/Return:	rr_RiskReturnAbstract
Supplement [Text Block]	cf2_SupplementTextBlock	SUPPLEMENT TO CALVERT INCOME FUNDS PROSPECTUS (CLASS I) DATED JANUARY 31, 2012 Calvert Income Fund Calvert Short Duration Income Fund Calvert Government Fund Calvert High Yield Bond Fund Date of Supplement: November 1, 2012 After the last paragraph in the section “Investments, Risks and Performance – Principal Investment Strategies” in each Fund Summary (Portfolio Summary for Calvert VP Income Portfolio), insert the following: Tobacco Exclusion. The Fund seeks to avoid investing in companies classified under the tobacco industry sector of the Barclays Global Aggregate Index, the Barclays U.S. High Yield Index or the Barclays Global Emerging Market Index; or, in the opinion of the Fund’s Advisor, any similar securities in the Barclays Municipal Index.
Institutional \| Calvert Short Duration Income Fund
Risk/Return:	rr_RiskReturnAbstract
Supplement [Text Block]	cf2_SupplementTextBlock	SUPPLEMENT TO CALVERT INCOME FUNDS PROSPECTUS (CLASS I) DATED JANUARY 31, 2012 Calvert Income Fund Calvert Short Duration Income Fund Calvert Government Fund Calvert High Yield Bond Fund Date of Supplement: November 1, 2012 After the last paragraph in the section “Investments, Risks and Performance – Principal Investment Strategies” in each Fund Summary (Portfolio Summary for Calvert VP Income Portfolio), insert the following: Tobacco Exclusion. The Fund seeks to avoid investing in companies classified under the tobacco industry sector of the Barclays Global Aggregate Index, the Barclays U.S. High Yield Index or the Barclays Global Emerging Market Index; or, in the opinion of the Fund’s Advisor, any similar securities in the Barclays Municipal Index.
Institutional \| Calvert Government Fund
Risk/Return:	rr_RiskReturnAbstract
Supplement [Text Block]	cf2_SupplementTextBlock	SUPPLEMENT TO CALVERT INCOME FUNDS PROSPECTUS (CLASS I) DATED JANUARY 31, 2012 Calvert Income Fund Calvert Short Duration Income Fund Calvert Government Fund Calvert High Yield Bond Fund Date of Supplement: November 1, 2012 After the last paragraph in the section “Investments, Risks and Performance – Principal Investment Strategies” in each Fund Summary (Portfolio Summary for Calvert VP Income Portfolio), insert the following: Tobacco Exclusion. The Fund seeks to avoid investing in companies classified under the tobacco industry sector of the Barclays Global Aggregate Index, the Barclays U.S. High Yield Index or the Barclays Global Emerging Market Index; or, in the opinion of the Fund’s Advisor, any similar securities in the Barclays Municipal Index.
Institutional \| Calvert High Yield Bond Fund
Risk/Return:	rr_RiskReturnAbstract
Supplement [Text Block]	cf2_SupplementTextBlock	SUPPLEMENT TO CALVERT INCOME FUNDS PROSPECTUS (CLASS I) DATED JANUARY 31, 2012 Calvert Income Fund Calvert Short Duration Income Fund Calvert Government Fund Calvert High Yield Bond Fund Date of Supplement: November 1, 2012 After the last paragraph in the section “Investments, Risks and Performance – Principal Investment Strategies” in each Fund Summary (Portfolio Summary for Calvert VP Income Portfolio), insert the following: Tobacco Exclusion. The Fund seeks to avoid investing in companies classified under the tobacco industry sector of the Barclays Global Aggregate Index, the Barclays U.S. High Yield Index or the Barclays Global Emerging Market Index; or, in the opinion of the Fund’s Advisor, any similar securities in the Barclays Municipal Index.

dei_EntityRegistrantName

CALVERT FUND

cf2_SupplementTextBlock

SUPPLEMENT TO

CALVERT INCOME FUNDS PROSPECTUS (CLASS A, B, C, O AND Y)
DATED JANUARY 31, 2012, AS REVISED APRIL 27, 2012
Calvert Income Fund
Calvert Short Duration Income Fund
Calvert Long-Term Income Fund
Calvert Ultra-Short Income Fund
Calvert Government Fund
Calvert High Yield Bond Fund

CALVERT INCOME FUNDS PROSPECTUS (CLASS I)
DATED JANUARY 31, 2012
Calvert Income Fund
Calvert Short Duration Income Fund
Calvert Government Fund
Calvert High Yield Bond Fund

Date of Supplement: November 1, 2012

After the last paragraph in the section “Investments, Risks and Performance – Principal Investment Strategies” in each Fund Summary (Portfolio Summary for Calvert VP Income Portfolio), insert the following:

Tobacco Exclusion. The Fund seeks to avoid investing in companies classified under the tobacco industry sector of the Barclays Global Aggregate Index, the Barclays U.S. High Yield Index or the Barclays Global Emerging Market Index; or, in the opinion of the Fund’s Advisor, any similar securities in the Barclays Municipal Index.

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cf2_SupplementTextBlock

SUPPLEMENT TO

CALVERT INCOME FUNDS PROSPECTUS (CLASS A, B, C, O AND Y)
DATED JANUARY 31, 2012, AS REVISED APRIL 27, 2012
Calvert Income Fund
Calvert Short Duration Income Fund
Calvert Long-Term Income Fund
Calvert Ultra-Short Income Fund
Calvert Government Fund
Calvert High Yield Bond Fund

Date of Supplement: November 1, 2012

After the last paragraph in the section “Investments, Risks and Performance – Principal Investment Strategies” in each Fund Summary (Portfolio Summary for Calvert VP Income Portfolio), insert the following:

Tobacco Exclusion. The Fund seeks to avoid investing in companies classified under the tobacco industry sector of the Barclays Global Aggregate Index, the Barclays U.S. High Yield Index or the Barclays Global Emerging Market Index; or, in the opinion of the Fund’s Advisor, any similar securities in the Barclays Municipal Index.

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cf2_SupplementTextBlock

SUPPLEMENT TO

CALVERT INCOME FUNDS PROSPECTUS (CLASS A, B, C, O AND Y)
DATED JANUARY 31, 2012, AS REVISED APRIL 27, 2012
Calvert Income Fund
Calvert Short Duration Income Fund
Calvert Long-Term Income Fund
Calvert Ultra-Short Income Fund
Calvert Government Fund
Calvert High Yield Bond Fund

Date of Supplement: November 1, 2012

After the last paragraph in the section “Investments, Risks and Performance – Principal Investment Strategies” in each Fund Summary (Portfolio Summary for Calvert VP Income Portfolio), insert the following:

Tobacco Exclusion. The Fund seeks to avoid investing in companies classified under the tobacco industry sector of the Barclays Global Aggregate Index, the Barclays U.S. High Yield Index or the Barclays Global Emerging Market Index; or, in the opinion of the Fund’s Advisor, any similar securities in the Barclays Municipal Index.

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cf2_SupplementTextBlock

SUPPLEMENT TO

CALVERT INCOME FUNDS PROSPECTUS (CLASS A, B, C, O AND Y)
DATED JANUARY 31, 2012, AS REVISED APRIL 27, 2012
Calvert Income Fund
Calvert Short Duration Income Fund
Calvert Long-Term Income Fund
Calvert Ultra-Short Income Fund
Calvert Government Fund
Calvert High Yield Bond Fund

Date of Supplement: November 1, 2012

After the last paragraph in the section “Investments, Risks and Performance – Principal Investment Strategies” in each Fund Summary (Portfolio Summary for Calvert VP Income Portfolio), insert the following:

Tobacco Exclusion. The Fund seeks to avoid investing in companies classified under the tobacco industry sector of the Barclays Global Aggregate Index, the Barclays U.S. High Yield Index or the Barclays Global Emerging Market Index; or, in the opinion of the Fund’s Advisor, any similar securities in the Barclays Municipal Index.

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cf2_SupplementTextBlock

SUPPLEMENT TO

CALVERT INCOME FUNDS PROSPECTUS (CLASS I)
DATED JANUARY 31, 2012
Calvert Income Fund
Calvert Short Duration Income Fund
Calvert Government Fund
Calvert High Yield Bond Fund

Date of Supplement: November 1, 2012

After the last paragraph in the section “Investments, Risks and Performance – Principal Investment Strategies” in each Fund Summary (Portfolio Summary for Calvert VP Income Portfolio), insert the following:

Tobacco Exclusion. The Fund seeks to avoid investing in companies classified under the tobacco industry sector of the Barclays Global Aggregate Index, the Barclays U.S. High Yield Index or the Barclays Global Emerging Market Index; or, in the opinion of the Fund’s Advisor, any similar securities in the Barclays Municipal Index.

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cf2_SupplementTextBlock

SUPPLEMENT TO

CALVERT INCOME FUNDS PROSPECTUS (CLASS I)
DATED JANUARY 31, 2012
Calvert Income Fund
Calvert Short Duration Income Fund
Calvert Government Fund
Calvert High Yield Bond Fund

Date of Supplement: November 1, 2012

After the last paragraph in the section “Investments, Risks and Performance – Principal Investment Strategies” in each Fund Summary (Portfolio Summary for Calvert VP Income Portfolio), insert the following:

Tobacco Exclusion. The Fund seeks to avoid investing in companies classified under the tobacco industry sector of the Barclays Global Aggregate Index, the Barclays U.S. High Yield Index or the Barclays Global Emerging Market Index; or, in the opinion of the Fund’s Advisor, any similar securities in the Barclays Municipal Index.