485BPOS

As filed with the Securities and Exchange Commission on December 7, 2012

Registration Nos. 33-29180

and 811-05823

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM N-1A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

POST-EFFECTIVE AMENDMENT NO. 44

AND

REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940

AMENDMENT NO. 46

DOMINI SOCIAL INVESTMENT TRUST

(Exact Name of Registrant as Specified in Charter)

532 Broadway, 9th Floor, New York, New York 10012

(Address of Principal Executive Offices)

Registrant’s Telephone Number, including Area Code: 212-217-1100

Amy Domini Thornton

Domini Social Investments LLC

532 Broadway, 9th Floor

New York, New York 10012

(Name and Address of Agent for Service)

Copy To:

Roger P. Joseph, Esq.

Bingham McCutchen LLP

One Federal Street

Boston, Massachusetts 02110

It is requested that this filing become effective immediately upon filing pursuant to paragraph (b) of Rule 485 under the Securities Act of 1933, as amended.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, and the Investment Company Act of 1940, as amended, the Registrant certifies that it meets all of the requirements for effectiveness of this Registration Statement under Rule 485(b) under the Securities Act of 1933 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, duly authorized, in the City of New York and the State of New York on the 7^th day of December, 2012.

DOMINI SOCIAL INVESTMENT TRUST
on behalf of its series:         Domini Social Equity Fund         Domini Social Bond Fund         Domini International Social Equity Fund
By:	/s/ Amy L. Thornton
	Amy L. Thornton
	President

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed below by the following persons in the capacities indicated below on December 7, 2012.

Signature	Title
/s/ Amy L. Thornton Amy L. Thornton	President (Principal Executive Officer) and Trustee of Domini Social Investment Trust
/s/ Carole M. Laible Carole M. Laible	Treasurer (Principal Accounting and Financial Officer) and Vice President of Domini Social Investment Trust
Julia Elizabeth Harris* Julia Elizabeth Harris	Trustee of Domini Social Investment Trust
Kirsten S. Moy* Kirsten S. Moy	Trustee of Domini Social Investment Trust
Gregory A. Ratliff* Gregory A. Ratliff	Trustee of Domini Social Investment Trust
John L. Shields* John L. Shields	Trustee of Domini Social Investment Trust
*By: /s/ Amy L. Thornton
Amy L. Thornton  Executed by Amy L. Thornton on behalf of those  indicated pursuant to Powers of Attorney dated  July 20, 2012.

INDEX TO EXHIBITS

EXHIBIT NO.	DESCRIPTION OF EXHIBIT
EX – 101.INS	XBRL Instance Document
EX – 101.SCH	XBRL Taxonomy Extension Schema Document
EX – 101.CAL	XBRL Taxonomy Extension Calculation Linkbase
EX – 101.DEF	XBRL Taxonomy Extension Definition Linkbase
EX – 101.LAB	XBRL Taxonomy Labels Linkbase
EX – 101.PRE	XBRL Taxonomy Presentation Linkbase

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	DOMINI SOCIAL INVESTMENT TRUST
Prospectus Date	rr_ProspectusDate	Nov. 30, 2012
Domini Social Bond Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	DOMINI SOCIAL BOND FUND®
Objective [Heading]	rr_ObjectiveHeading	Investment objective:
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund seeks to provide its shareholders with a high level of current income and total return.
Expense [Heading]	rr_ExpenseHeading	Fees and expenses of the Fund:
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	Shareholder fees (paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	November 30, 2013
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio turnover:
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual Fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 126% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	126.00%
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated, that your investment has a 5% return each year, and that the Fund’s operating expenses (reflecting applicable contractual fee waivers and expense reimbursement arrangements) remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be as follows:
Expense Example by, Year, Caption [Text]	rr_ExpenseExampleByYearCaption	Share classes (whether or not shares are redeemed)
Expense Example, No Redemption, By Year, Caption [Text]	rr_ExpenseExampleNoRedemptionByYearCaption	Share classes (whether or not shares are redeemed)
Strategy [Heading]	rr_StrategyHeading	Principal investment strategies:
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	Under normal circumstances, the Fund invests at least 85% of its assets in investment-grade securities and maintains a dollar-weighted average effective maturity of between two and ten years. Under normal circumstances, at least 80% of the Fund’s assets will be invested in bonds, including government and corporate bonds, mortgage-backed and asset-backed securities, and U.S. dollar denominated bonds issued by non-U.S. entities. Some of these instruments may not be insured and may earn below-market rates of return. Some investments may be unrated, lower-rated, or illiquid securities. Domini evaluates the Fund’s potential corporate debt instruments against its social and environmental standards based on the businesses in which they engage, as well as on the quality of their relations with key stakeholders, including communities, customers, ecosystems, employees, investors, and suppliers. For noncorporate issuers, Domini seeks to identify investments with a positive impact on communities. For additional information about the standards Domini uses to evaluate potential investments and the securities held by the Fund, and certain limitations on investment, please see “Socially Responsible Investing.” Domini reserves the right to alter its social and environmental standards or the application of those standards, or to add new standards, at any time without shareholder approval.
Risk [Heading]	rr_RiskHeading	Principal risks:
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	Risk is inherent in all investing. The value of your investment in the Fund, as well as the amount of return you receive on your investment, may fluctuate significantly in the short and long term. You may lose all or part of your investment in the Fund or your investment may not perform as well as other similar investments. The following is a summary description of certain risks of investing in the Fund. Credit risk. Fixed-income securities are subject to credit risk. Credit risk is the possibility that an issuer will fail to make timely payments of interest or principal, or go bankrupt. The lower the ratings of such debt securities, the greater their risks. In addition, lower-rated securities have higher risk characteristics, and changes in economic conditions are likely to cause issuers of these securities to be unable to meet their obligations. Below investment grade securities (sometimes referred to as “junk bonds”) involve greater risk of default or downgrade and are more volatile than investment grade securities. Below investment grade securities may also be less liquid than higher-quality securities. Government-Sponsored Entities risk. The Fund’s investments in securities issued by government-sponsored entities such as Fannie Mae, Freddie Mac, and the Federal Home Loan Bank are not guaranteed or insured by the U.S. government and may decline in value. Information risk. There is a risk that information used by the adviser to evaluate the social and environmental performance of issuers, industries, markets, and sectors, may not be readily available, complete, or accurate, which could negatively impact the adviser’s ability to apply its social and environmental standards which may negatively impact Fund performance. This may also lead the Fund to avoid investment in certain issuers, industries, markets, or sectors. Interest Rate risk. The value of your investment will fluctuate with interest rates. If interest rates rise, the price of a fixed-income security declines and could reduce the value of the Fund’s share price. A rise in rates tends to have a greater impact on securities with longer maturities or higher durations. Liquidity risk. Some securities held by the Fund may be difficult to sell, or may be illiquid, particularly during times of market turmoil. Illiquid securities also may be difficult to value. Due to limitations on investments in illiquid securities the Fund may be unable to achieve its desired level of exposure to certain sectors. If the Fund is forced to sell an illiquid asset to meet redemption request or other cash needs, the Fund may be forced to sell such securities at a loss. Market risk. The market prices of Fund securities may go up or down, sometimes rapidly or unpredictably, due to general market conditions, such as real or perceived adverse economic or political conditions, inflation, changes in interest rates, lack of liquidity in the markets, or adverse investor sentiment. When market prices fall, the value of your investment will go down. The financial crisis that began in 2008 caused a significant decline in the value and liquidity of many securities of issuers worldwide. Some government and non-governmental issuers (notably in Europe) have defaulted on, or been forced to restructure their debts, and many other issuers have faced difficulties in obtaining credit. These market conditions may continue to worsen or spread, including in the U.S., Europe, and beyond. Further defaults or restructurings of their debt by governments and others could have additional adverse effects on economies, financial markets, and asset valuations around the world. Whether or not the Fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, these events could negatively affect the value and liquidity of the Fund’s investments. Legislation recently enacted in the U.S. calls for changes in many aspects of financial regulation. The impact of the legislation on the markets, and the practical implications for market participants, may not be fully known for some time. Prepayment and Extension risk. Many issuers have a right to prepay their securities. If interest rates fall, an issuer may exercise this right. If this happens, the Fund will be forced to reinvest prepayment proceeds at a time when yields on securities available in the market are lower than the yield on the prepaid security. The Fund also may lose any premium it paid on the security. If interest rates rise, repayments of fixed-income securities may occur more slowly than anticipated by the market. This may drive the prices of these securities down because their interest rates are lower than the current interest rate and they remain outstanding longer. Socially Responsible Investing risk. The application of the adviser’s social and environmental standards will affect the Fund’s exposure to certain issuers, industries, and sectors and may impact the relative financial performance of the Fund — positively or negatively — depending on whether such investments are in or out of favor. These and other risks are discussed in more detail later in this prospectus or in the SAI. Please note that there are many other factors that could adversely affect your investment and that could prevent the Fund from achieving its goals.
Risk Lose Money [Text]	rr_RiskLoseMoney	You may lose all or part of your investment in the Fund or your investment may not perform as well as other similar investments.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Investment results:
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and by showing how the Fund’s average annual total returns for 1, 5, and 10 years, as applicable, compare with those of a broad measure of market performance, the Barclays Capital Intermediate Aggregate Index (BCIA), an unmanaged index of intermediate investment-grade fixed-income securities. The returns for each class of the Fund will differ from Investor shares because of the different expenses applicable to those share classes. The returns presented in the table for periods prior to the inception of the Institutional shares reflect the performance of the Investor shares. Institutional shares commenced operations on November 30, 2011. These returns have not been adjusted to take into account the lower expenses applicable to Institutional shares. Updated information on the Fund’s investment results can be obtained by visiting www.domini.com/performance and by calling 1-800-582-6757. The Fund’s past results (before and after taxes) are not necessarily an indication of how the Fund will perform in the future.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and by showing how the Fund’s average annual total returns for 1, 5, and 10 years, as applicable, compare with those of a broad measure of market performance, the Barclays Capital Intermediate Aggregate Index (BCIA), an unmanaged index of intermediate investment-grade fixed-income securities.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	1-800-582-6757
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.domini.com/performance
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	The Fund’s past results (before and after taxes) are not necessarily an indication of how the Fund will perform in the future.
Bar Chart [Heading]	rr_BarChartHeading	Average Annual Total Return (%)
Bar Chart Footnotes [Text Block]	rr_BarChartFootnotesTextBlock	Calendar years ended December 31
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Highest/lowest quarterly results during this time period were: 4.49% (quarter ended 12/31/08) and –2.58% (quarter ended 06/30/04). The Fund’s year-to-date results as of the most recent calendar quarter ended 9/30/12, were 2.61%.
Performance Table Heading	rr_PerformanceTableHeading	Average annual total returns for periods ended December 31, 2011
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	After-tax returns are calculated using the highest individual marginal federal income tax rates in effect during each year of the periods shown and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	Your actual after-tax returns depend on your individual tax situation and likely will differ from the results shown above. In addition, after-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as a 401(k) plan or individual retirement account (IRA).
Performance Table One Class of after Tax Shown [Text]	rr_PerformanceTableOneClassOfAfterTaxShown	After-tax returns are shown only for Investor shares; after-tax returns for other share classes will vary.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	After-tax returns are shown only for Investor shares; after-tax returns for other share classes will vary. After-tax returns are calculated using the highest individual marginal federal income tax rates in effect during each year of the periods shown and do not reflect the impact of state and local taxes. Your actual after-tax returns depend on your individual tax situation and likely will differ from the results shown above. In addition, after-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as a 401(k) plan or individual retirement account (IRA).
Domini Social Bond Fund | Investor
Risk/Return:	rr_RiskReturnAbstract
Redemption fee on shares held less than 30 days (as a percentage of amount redeemed, if applicable)	rr_RedemptionFeeOverRedemption	(2.00%)
Paper document delivery fee (choose e-delivery to avoid this fee)	rr_MaximumAccountFee	15	[1],[2]
Management fees	rr_ManagementFeesOverAssets	0.40%
Distribution (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Administrative services fee	rr_Component2OtherExpensesOverAssets	0.25%
Other miscellaneous expenses	rr_Component3OtherExpensesOverAssets	0.38%
Total other expenses	rr_OtherExpensesOverAssets	0.63%
Total annual Fund operating expenses	rr_ExpensesOverAssets	1.28%
Fee waivers and expense reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.33%)	[3]
Total annual Fund operating expenses after fee waivers and expense reimbursements	rr_NetExpensesOverAssets	0.95%
1 Year	rr_ExpenseExampleYear01	97
3 Years	rr_ExpenseExampleYear03	373
5 Years	rr_ExpenseExampleYear05	671
10 Years	rr_ExpenseExampleYear10	1,516
1 Year	rr_ExpenseExampleNoRedemptionYear01	97
3 Years	rr_ExpenseExampleNoRedemptionYear03	373
5 Years	rr_ExpenseExampleNoRedemptionYear05	671
10 Years	rr_ExpenseExampleNoRedemptionYear10	1,516
2002	rr_AnnualReturn2002	8.85%
2003	rr_AnnualReturn2003	2.31%
2004	rr_AnnualReturn2004	2.81%
2005	rr_AnnualReturn2005	1.56%
2006	rr_AnnualReturn2006	3.38%
2007	rr_AnnualReturn2007	6.00%
2008	rr_AnnualReturn2008	5.69%
2009	rr_AnnualReturn2009	5.77%
2010	rr_AnnualReturn2010	4.74%
2011	rr_AnnualReturn2011	5.85%
Year to Date Return, Label	rr_YearToDateReturnLabel	year-to-date
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Sep. 30, 2012
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	2.61%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Dec. 31, 2008
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	4.49%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	lowest
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Jun. 30, 2004
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(2.58%)
1 Year	rr_AverageAnnualReturnYear01	5.85%
5 Years	rr_AverageAnnualReturnYear05	5.61%
10 Years	rr_AverageAnnualReturnYear10	4.68%
Domini Social Bond Fund | Institutional
Risk/Return:	rr_RiskReturnAbstract
Redemption fee on shares held less than 30 days (as a percentage of amount redeemed, if applicable)	rr_RedemptionFeeOverRedemption	(2.00%)
Paper document delivery fee (choose e-delivery to avoid this fee)	rr_MaximumAccountFee	15	[1],[2]
Management fees	rr_ManagementFeesOverAssets	0.40%
Distribution (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Administrative services fee	rr_Component2OtherExpensesOverAssets	0.25%
Other miscellaneous expenses	rr_Component3OtherExpensesOverAssets	3.34%
Total other expenses	rr_OtherExpensesOverAssets	3.59%
Total annual Fund operating expenses	rr_ExpensesOverAssets	3.99%
Fee waivers and expense reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(3.34%)	[3]
Total annual Fund operating expenses after fee waivers and expense reimbursements	rr_NetExpensesOverAssets	0.65%
1 Year	rr_ExpenseExampleYear01	66
3 Years	rr_ExpenseExampleYear03	908
5 Years	rr_ExpenseExampleYear05	1,766
10 Years	rr_ExpenseExampleYear10	3,988
1 Year	rr_ExpenseExampleNoRedemptionYear01	66
3 Years	rr_ExpenseExampleNoRedemptionYear03	908
5 Years	rr_ExpenseExampleNoRedemptionYear05	1,766
10 Years	rr_ExpenseExampleNoRedemptionYear10	3,988
1 Year	rr_AverageAnnualReturnYear01	5.85%
5 Years	rr_AverageAnnualReturnYear05	5.61%
10 Years	rr_AverageAnnualReturnYear10	4.68%
Domini Social Bond Fund | Return after taxes on distributions | Investor
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	4.39%
5 Years	rr_AverageAnnualReturnYear05	4.23%
10 Years	rr_AverageAnnualReturnYear10	3.30%
Domini Social Bond Fund | Return after taxes on distributions and sale of shares | Investor
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	4.15%
5 Years	rr_AverageAnnualReturnYear05	4.04%
10 Years	rr_AverageAnnualReturnYear10	3.22%
Domini Social Bond Fund | BCIA (reflects no deduction for fees, expenses, or taxes)
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	5.97%
5 Years	rr_AverageAnnualReturnYear05	6.09%
10 Years	rr_AverageAnnualReturnYear10	5.39%

[1] Paper document delivery fee applies to direct Fund accounts with balances below $10,000 and may be avoided by choosing e-delivery of Fund statements, prospectuses, and reports.

[2] /year

[3] The Fund's adviser has contractually agreed to waive certain fees and/or reimburse certain ordinary operating expenses in order to limit Investor and Institutional share expenses to 0.95% and 0.65%, respectively. The agreement expires on November 30, 2013, absent an earlier modification by the Fund's Board.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	DOMINI SOCIAL INVESTMENT TRUST
Prospectus Date	rr_ProspectusDate	Nov. 30, 2012
Domini Social Equity Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	DOMINI SOCIAL EQUITY FUND®
Objective [Heading]	rr_ObjectiveHeading	Investment objective:
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund seeks to provide its shareholders with long-term total return.
Expense [Heading]	rr_ExpenseHeading	Fees and expenses of the Fund:
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for Class A sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in the Investor or Class A shares of each Domini Fund, except the Domini Social Bond Fund. More information about these and other discounts is available from your financial professional or in the Fund’s prospectus on page A-15 under the heading “How Sales Charges Are Calculated for Class A Shares” and in the Fund’s Statement of Additional Information (“SAI”) on page 32 under the heading “Additional Information Regarding Class A Sales Charges.”
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	Shareholder fees (paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	November 30, 2013
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio turnover:
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual Fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 94% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	94.00%
Expense Breakpoint Discounts [Text]	rr_ExpenseBreakpointDiscounts	You may qualify for Class A sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in the Investor or Class A shares of each Domini Fund, except the Domini Social Bond Fund.
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	50,000
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated, that your investment has a 5% return each year, and that the Fund’s operating expenses (reflecting applicable contractual fee waivers and expense reimbursement arrangements) remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be as follows:
Expense Example by, Year, Caption [Text]	rr_ExpenseExampleByYearCaption	Share classes (whether or not shares are redeemed)
Expense Example, No Redemption, By Year, Caption [Text]	rr_ExpenseExampleNoRedemptionByYearCaption	Share classes (whether or not shares are redeemed)
Strategy [Heading]	rr_StrategyHeading	Principal investment strategies:
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	Under normal circumstances, the Fund primarily invests in the equity securities of mid- and large-capitalization U.S. companies. Under normal circumstances, at least 80% of the Fund’s assets will be invested in equity securities and related investments with similar economic characteristics. The Fund may also invest in companies organized or traded outside the U.S. (or in equivalent shares such as ADRs). Domini evaluates the Fund’s potential investments against its social and environmental standards based on the businesses in which they engage, as well as on the quality of their relations with key stakeholders, including communities, customers, ecosystems, employees, investors, and suppliers. For additional information about the standards Domini uses to evaluate potential investments and the securities held by the Fund, and certain limitations on investments, please see “Socially Responsible Investing.” Domini reserves the right to alter its social and environmental standards or the application of those standards, or to add new standards, at any time without shareholder approval.
Risk [Heading]	rr_RiskHeading	Principal risks:
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	Risk is inherent in all investing. The value of your investment in the Fund, as well as the amount of return you receive on your investment, may fluctuate significantly in the short and long term. You may lose all or part of your investment in the Fund or your investment may not perform as well as other similar investments. The following is a summary description of certain risks of investing in the Fund. Foreign Investing risk. Investments in foreign regions or in securities of issuers with significant exposure to foreign markets may be more volatile and less liquid than U.S. investments due to adverse political, social, and economic developments, such as nationalization or expropriation of assets, imposition of currency controls or restrictions, confiscatory taxation, and political or financial instability; regulatory differences such as accounting, auditing, and financial reporting standards and practices; natural disasters; and the degree of government oversight and supervision. Information risk. There is a risk that information used by the adviser to evaluate the social and environmental performance of issuers, industries, markets, sectors, and regions may not be readily available, complete, or accurate, which could negatively impact the adviser’s ability to apply its social and environmental standards, which may negatively impact Fund performance. This may also lead the Fund to avoid investment in certain issuers, industries, markets, sectors, or regions. Market risk. The market prices of Fund securities may go up or down, sometimes rapidly or unpredictably, due to general market conditions, such as real or perceived adverse economic or political conditions, inflation, changes in interest rates, lack of liquidity in the markets, or adverse investor sentiment. When market prices fall, the value of your investment will go down. The financial crisis that began in 2008 caused a significant decline in the value and liquidity of many securities of issuers worldwide. Some government and non-governmental issuers (notably in Europe) have defaulted on, or been forced to restructure their debts, and many other issuers have faced difficulties in obtaining credit. These market conditions may continue to worsen or spread, including in the U.S., Europe, and beyond. Further defaults or restructurings of their debt by governments and others could have additional adverse effects on economies, financial markets, and asset valuations around the world. Whether or not the Fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, these events could negatively affect the value and liquidity of the Fund’s investments. Legislation recently enacted in the U.S. calls for changes in many aspects of financial regulation. The impact of the legislation on the markets, and the practical implications for market participants, may not be fully known for some time. Mid-to Large-Cap Companies risk. The market prices of companies at different capitalization levels may go up or down due to general market conditions and cycles. The value of your investment will be affected by the Fund’s exposure to mid- and large-cap companies. Sector Concentration risk. The Fund may hold a large percentage of securities in a single sector (e.g., financials). If the Fund holds a large percentage of securities in a single sector, its performance will be tied closely to and affected by the performance of that sector. Socially Responsible Investing risk. The application of the adviser’s social and environmental standards will affect the Fund’s exposure to certain issuers, industries, sectors, regions, and countries and may impact the relative financial performance of the Fund — positively or negatively — depending on whether such investments are in or out of favor. Style risk. The value of your investment may decrease if the subadviser’s quantitative investment approach does not respond well to current market conditions or its judgment regarding the quality, value, or market trends affecting a particular security, industry, sector or region is incorrect. The submanager’s quantitative model relies upon a complex software system, and failure of the system to function or the presence of software errors could have an adverse impact on the value of Fund performance. These and other risks are discussed in more detail later in this prospectus or in the SAI. Please note that there are many other factors that could adversely affect your investment and that could prevent the Fund from achieving its goals.
Risk Lose Money [Text]	rr_RiskLoseMoney	You may lose all or part of your investment in the Fund or your investment may not perform as well as other similar investments.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Investment results:
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year for Investor shares and by showing how the Fund’s average annual total returns for 1, 5, and 10 years compare with those of a broad measure of market performance, the Standard and Poor’s 500 Index (S&P 500), an unmanaged index of common stocks. The returns for each class of the Fund will differ from Investor shares because of the different expenses applicable to those share classes. The returns presented in the table for periods prior to the inception of the Class A, Institutional, and Class R shares reflect the performance of the Investor shares. Class A shares and Institutional shares commenced operations on November 28, 2008. Class R shares commenced operations on November 28, 2003. These returns have not been adjusted to take into account the lower expenses applicable to Class A, Institutional, and Class R shares, but for Class A shares, the returns in the table reflect a deduction for the maximum sales charge. Updated information on the Fund’s investment results can be obtained by visiting www.domini.com/performance or by calling 1-800-582-6757. The Fund’s past results (before and after taxes) are not necessarily an indication of how the Fund will perform in the future.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year for Investor shares and by showing how the Fund’s average annual total returns for 1, 5, and 10 years compare with those of a broad measure of market performance, the Standard and Poor’s 500 Index (S&P 500), an unmanaged index of common stocks.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	1-800-582-6757
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.domini.com/performance
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	The Fund’s past results (before and after taxes) are not necessarily an indication of how the Fund will perform in the future.
Bar Chart [Heading]	rr_BarChartHeading	Average Annual Total Return (%)
Bar Chart Footnotes [Text Block]	rr_BarChartFootnotesTextBlock	Calendar years ended December 31
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Highest/lowest quarterly results during this time period were: 20.58% (quarter ended 6/30/09) and –24.04% (quarter ended 12/31/08). The Fund’s year-to-date results as of the most recent calendar quarter ended 9/30/12, were 14.31%.
Performance Table Heading	rr_PerformanceTableHeading	Average annual total returns for periods ended December 31, 2011 (with maximum sales charge for Class A shares)
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	After-tax returns are calculated using the highest individual marginal federal income tax rates in effect during each year of the periods shown and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	Your actual after-tax returns depend on your individual tax situation and likely will differ from the results shown above. In addition, after-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as a 401(k) plan or individual retirement account (IRA).
Performance Table One Class of after Tax Shown [Text]	rr_PerformanceTableOneClassOfAfterTaxShown	After-tax returns are shown only for Investor shares; after-tax returns for other share classes will vary.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	After-tax returns are shown only for Investor shares; after-tax returns for other share classes will vary. After-tax returns are calculated using the highest individual marginal federal income tax rates in effect during each year of the periods shown and do not reflect the impact of state and local taxes. Your actual after-tax returns depend on your individual tax situation and likely will differ from the results shown above. In addition, after-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as a 401(k) plan or individual retirement account (IRA).
Domini Social Equity Fund | Investor
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases as a percentage of offering price	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Redemption fee on shares held less than 30 days (as a percentage of amount redeemed, if applicable)	rr_RedemptionFeeOverRedemption	2.00%
Paper document delivery fee (choose e-delivery to avoid this fee)	rr_MaximumAccountFee	15	[1],[2]
Management fees	rr_ManagementFeesOverAssets	0.30%
Distribution (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Sponsorship fee	rr_Component1OtherExpensesOverAssets	0.45%
Other miscellaneous expenses	rr_Component3OtherExpensesOverAssets	0.26%
Total other expenses	rr_OtherExpensesOverAssets	0.71%
Total annual Fund operating expenses	rr_ExpensesOverAssets	1.26%
Fee waiver and expense reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.01%)	[3]
Total annual Fund operating expenses after fee waiver and expense reimbursements	rr_NetExpensesOverAssets	1.25%
1 Year	rr_ExpenseExampleYear01	127
3 Years	rr_ExpenseExampleYear03	399
5 Years	rr_ExpenseExampleYear05	691
10 Years	rr_ExpenseExampleYear10	1,522
1 Year	rr_ExpenseExampleNoRedemptionYear01	127
3 Years	rr_ExpenseExampleNoRedemptionYear03	399
5 Years	rr_ExpenseExampleNoRedemptionYear05	691
10 Years	rr_ExpenseExampleNoRedemptionYear10	1,522
2002	rr_AnnualReturn2002	(20.69%)
2003	rr_AnnualReturn2003	27.13%
2004	rr_AnnualReturn2004	9.26%
2005	rr_AnnualReturn2005	2.03%
2006	rr_AnnualReturn2006	12.58%
2007	rr_AnnualReturn2007	1.46%
2008	rr_AnnualReturn2008	(37.88%)
2009	rr_AnnualReturn2009	35.56%
2010	rr_AnnualReturn2010	13.69%
2011	rr_AnnualReturn2011	0.74%
Year to Date Return, Label	rr_YearToDateReturnLabel	year-to-date
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Sep. 30, 2012
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	14.31%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	20.58%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	lowest
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(24.04%)
1 Year	rr_AverageAnnualReturnYear01	0.74%
5 Years	rr_AverageAnnualReturnYear05	(0.43%)
10 Years	rr_AverageAnnualReturnYear10	2.16%
Domini Social Equity Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases as a percentage of offering price	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	4.75%
Redemption fee on shares held less than 30 days (as a percentage of amount redeemed, if applicable)	rr_RedemptionFeeOverRedemption	2.00%
Paper document delivery fee (choose e-delivery to avoid this fee)	rr_MaximumAccountFee	15	[1],[2]
Management fees	rr_ManagementFeesOverAssets	0.30%
Distribution (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Sponsorship fee	rr_Component1OtherExpensesOverAssets	0.45%
Other miscellaneous expenses	rr_Component3OtherExpensesOverAssets	1.09%
Total other expenses	rr_OtherExpensesOverAssets	1.54%
Total annual Fund operating expenses	rr_ExpensesOverAssets	2.09%
Fee waiver and expense reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.91%)	[3]
Total annual Fund operating expenses after fee waiver and expense reimbursements	rr_NetExpensesOverAssets	1.18%
1 Year	rr_ExpenseExampleYear01	590
3 Years	rr_ExpenseExampleYear03	1,015
5 Years	rr_ExpenseExampleYear05	1,466
10 Years	rr_ExpenseExampleYear10	2,712
1 Year	rr_ExpenseExampleNoRedemptionYear01	590
3 Years	rr_ExpenseExampleNoRedemptionYear03	1,015
5 Years	rr_ExpenseExampleNoRedemptionYear05	1,466
10 Years	rr_ExpenseExampleNoRedemptionYear10	2,712
1 Year	rr_AverageAnnualReturnYear01	(3.94%)
5 Years	rr_AverageAnnualReturnYear05	(1.40%)
10 Years	rr_AverageAnnualReturnYear10	1.66%
Domini Social Equity Fund | Institutional
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases as a percentage of offering price	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Redemption fee on shares held less than 30 days (as a percentage of amount redeemed, if applicable)	rr_RedemptionFeeOverRedemption	2.00%
Paper document delivery fee (choose e-delivery to avoid this fee)	rr_MaximumAccountFee	15	[1],[2]
Management fees	rr_ManagementFeesOverAssets	0.30%
Distribution (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Sponsorship fee	rr_Component1OtherExpensesOverAssets	0.45%
Other miscellaneous expenses	rr_Component3OtherExpensesOverAssets	0.08%
Total other expenses	rr_OtherExpensesOverAssets	0.53%
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.83%
Fee waiver and expense reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.03%)	[3]
Total annual Fund operating expenses after fee waiver and expense reimbursements	rr_NetExpensesOverAssets	0.80%
1 Year	rr_ExpenseExampleYear01	82
3 Years	rr_ExpenseExampleYear03	262
5 Years	rr_ExpenseExampleYear05	458
10 Years	rr_ExpenseExampleYear10	1,023
1 Year	rr_ExpenseExampleNoRedemptionYear01	82
3 Years	rr_ExpenseExampleNoRedemptionYear03	262
5 Years	rr_ExpenseExampleNoRedemptionYear05	458
10 Years	rr_ExpenseExampleNoRedemptionYear10	1,023
1 Year	rr_AverageAnnualReturnYear01	1.12%
5 Years	rr_AverageAnnualReturnYear05	(0.43%)
10 Years	rr_AverageAnnualReturnYear10	2.16%
Domini Social Equity Fund | Class R
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases as a percentage of offering price	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Redemption fee on shares held less than 30 days (as a percentage of amount redeemed, if applicable)	rr_RedemptionFeeOverRedemption	2.00%
Paper document delivery fee (choose e-delivery to avoid this fee)	rr_MaximumAccountFee	15	[1],[2]
Management fees	rr_ManagementFeesOverAssets	0.30%
Distribution (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Sponsorship fee	rr_Component1OtherExpensesOverAssets	0.45%
Other miscellaneous expenses	rr_Component3OtherExpensesOverAssets	0.16%
Total other expenses	rr_OtherExpensesOverAssets	0.61%
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.91%
Fee waiver and expense reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.01%)	[3]
Total annual Fund operating expenses after fee waiver and expense reimbursements	rr_NetExpensesOverAssets	0.90%
1 Year	rr_ExpenseExampleYear01	92
3 Years	rr_ExpenseExampleYear03	289
5 Years	rr_ExpenseExampleYear05	503
10 Years	rr_ExpenseExampleYear10	1,119
1 Year	rr_ExpenseExampleNoRedemptionYear01	92
3 Years	rr_ExpenseExampleNoRedemptionYear03	289
5 Years	rr_ExpenseExampleNoRedemptionYear05	503
10 Years	rr_ExpenseExampleNoRedemptionYear10	1,119
1 Year	rr_AverageAnnualReturnYear01	0.96%
5 Years	rr_AverageAnnualReturnYear05	(0.08%)
10 Years	rr_AverageAnnualReturnYear10	2.43%
Domini Social Equity Fund | Return after taxes on distributions | Investor
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	0.66%
5 Years	rr_AverageAnnualReturnYear05	(0.70%)
10 Years	rr_AverageAnnualReturnYear10	1.92%
Domini Social Equity Fund | Return after taxes on distributions and sale of shares | Investor
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	0.59%
5 Years	rr_AverageAnnualReturnYear05	(0.38%)
10 Years	rr_AverageAnnualReturnYear10	1.80%
Domini Social Equity Fund | S&P 500 (reflects no deduction for fees, expenses, or taxes)
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	2.11%
5 Years	rr_AverageAnnualReturnYear05	(0.25%)
10 Years	rr_AverageAnnualReturnYear10	2.92%

[1] Paper document delivery fee applies to direct Fund accounts with balances below $10,000 and may be avoided by choosing e-delivery of Fund statements, prospectuses, and reports.

[2] /year

[3] The Fund's adviser has contractually agreed to waive certain fees and/or reimburse certain ordinary operating expenses in order to limit Investor, Class A, Institutional, and Class R share expenses to 1.25%, 1.18%, 0.80%, and 0.90%, respectively. The agreement expires on November 30, 2013, absent an earlier modification by the Fund's Board.

XML

Domini Social Equity Fund

DOMINI SOCIAL EQUITY FUND^®

Investment objective:

The Fund seeks to provide its shareholders with long-term total return.

Fees and expenses of the Fund:

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for Class A sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in the Investor or Class A shares of each Domini Fund, except the Domini Social Bond Fund. More information about these and other discounts is available from your financial professional or in the Fund’s prospectus on page A-15 under the heading “How Sales Charges Are Calculated for Class A Shares” and in the Fund’s Statement of Additional Information (“SAI”) on page 32 under the heading “Additional Information Regarding Class A Sales Charges.”

Shareholder fees (paid directly from your investment)

Shareholder Fees Domini Social Equity Fund (USD $)		Investor	Class A	Institutional	Class R
Maximum sales charge (load) imposed on purchases as a percentage of offering price		none	4.75%	none	none
Redemption fee on shares held less than 30 days (as a percentage of amount redeemed, if applicable)		2.00%	2.00%	2.00%	2.00%
Paper document delivery fee (choose e-delivery to avoid this fee)	[1][2]	15	15	15	15

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

Annual Fund Operating Expenses Domini Social Equity Fund		Investor	Class A	Institutional	Class R
Management fees		0.30%	0.30%	0.30%	0.30%
Distribution (12b-1) fees		0.25%	0.25%	none	none
Sponsorship fee		0.45%	0.45%	0.45%	0.45%
Other miscellaneous expenses		0.26%	1.09%	0.08%	0.16%
Total other expenses		0.71%	1.54%	0.53%	0.61%
Total annual Fund operating expenses		1.26%	2.09%	0.83%	0.91%
Fee waiver and expense reimbursements	[1]	(0.01%)	(0.91%)	(0.03%)	(0.01%)
Total annual Fund operating expenses after fee waiver and expense reimbursements		1.25%	1.18%	0.80%	0.90%

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated, that your investment has a 5% return each year, and that the Fund’s operating expenses (reflecting applicable contractual fee waivers and expense reimbursement arrangements) remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be as follows:

Share classes (whether or not shares are redeemed)

Expense Example Domini Social Equity Fund (USD $)	1 Year	3 Years	5 Years	10 Years
Investor	127	399	691	1,522
Class A	590	1,015	1,466	2,712
Institutional	82	262	458	1,023
Class R	92	289	503	1,119

Share classes (whether or not shares are redeemed)

Expense Example, No Redemption Domini Social Equity Fund (USD $)	1 Year	3 Years	5 Years	10 Years
Investor	127	399	691	1,522
Class A	590	1,015	1,466	2,712
Institutional	82	262	458	1,023
Class R	92	289	503	1,119

Portfolio turnover:

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual Fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 94% of the average value of its portfolio.

Principal investment strategies:

Under normal circumstances, the Fund primarily invests in the equity securities of mid- and large-capitalization U.S. companies. Under normal circumstances, at least 80% of the Fund’s assets will be invested in equity securities and related investments with similar economic characteristics. The Fund may also invest in companies organized or traded outside the U.S. (or in equivalent shares such as ADRs). Domini evaluates the Fund’s potential investments against its social and environmental standards based on the businesses in which they engage, as well as on the quality of their relations with key stakeholders, including communities, customers, ecosystems, employees, investors, and suppliers. For additional information about the standards Domini uses to evaluate potential investments and the securities held by the Fund, and certain limitations on investments, please see “Socially Responsible Investing.” Domini reserves the right to alter its social and environmental standards or the application of those standards, or to add new standards, at any time without shareholder approval.

Principal risks:

Risk is inherent in all investing. The value of your investment in the Fund, as well as the amount of return you receive on your investment, may fluctuate significantly in the short and long term. You may lose all or part of your investment in the Fund or your investment may not perform as well as other similar investments. The following is a summary description of certain risks of investing in the Fund.

• Foreign Investing risk. Investments in foreign regions or in securities of issuers with significant exposure to foreign markets may be more volatile and less liquid than U.S. investments due to adverse political, social, and economic developments, such as nationalization or expropriation of assets, imposition of currency controls or restrictions, confiscatory taxation, and political or financial instability; regulatory differences such as accounting, auditing, and financial reporting standards and practices; natural disasters; and the degree of government oversight and supervision.

• Information risk. There is a risk that information used by the adviser to evaluate the social and environmental performance of issuers, industries, markets, sectors, and regions may not be readily available, complete, or accurate, which could negatively impact the adviser’s ability to apply its social and environmental standards, which may negatively impact Fund performance. This may also lead the Fund to avoid investment in certain issuers, industries, markets, sectors, or regions.

• Market risk. The market prices of Fund securities may go up or down, sometimes rapidly or unpredictably, due to general market conditions, such as real or perceived adverse economic or political conditions, inflation, changes in interest rates, lack of liquidity in the markets, or adverse investor sentiment. When market prices fall, the value of your investment will go down. The financial crisis that began in 2008 caused a significant decline in the value and liquidity of many securities of issuers worldwide. Some government and non-governmental issuers (notably in Europe) have defaulted on, or been forced to restructure their debts, and many other issuers have faced difficulties in obtaining credit. These market conditions may continue to worsen or spread, including in the U.S., Europe, and beyond. Further defaults or restructurings of their debt by governments and others could have additional adverse effects on economies, financial markets, and asset valuations around the world. Whether or not the Fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, these events could negatively affect the value and liquidity of the Fund’s investments. Legislation recently enacted in the U.S. calls for changes in many aspects of financial regulation. The impact of the legislation on the markets, and the practical implications for market participants, may not be fully known for some time.

• Mid-to Large-Cap Companies risk. The market prices of companies at different capitalization levels may go up or down due to general market conditions and cycles. The value of your investment will be affected by the Fund’s exposure to mid- and large-cap companies.

• Sector Concentration risk. The Fund may hold a large percentage of securities in a single sector (e.g., financials). If the Fund holds a large percentage of securities in a single sector, its performance will be tied closely to and affected by the performance of that sector.

• Socially Responsible Investing risk. The application of the adviser’s social and environmental standards will affect the Fund’s exposure to certain issuers, industries, sectors, regions, and countries and may impact the relative financial performance of the Fund — positively or negatively — depending on whether such investments are in or out of favor.

• Style risk. The value of your investment may decrease if the subadviser’s quantitative investment approach does not respond well to current market conditions or its judgment regarding the quality, value, or market trends affecting a particular security, industry, sector or region is incorrect. The submanager’s quantitative model relies upon a complex software system, and failure of the system to function or the presence of software errors could have an adverse impact on the value of Fund performance.

These and other risks are discussed in more detail later in this prospectus or in the SAI. Please note that there are many other factors that could adversely affect your investment and that could prevent the Fund from achieving its goals.

Investment results:

The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year for Investor shares and by showing how the Fund’s average annual total returns for 1, 5, and 10 years compare with those of a broad measure of market performance, the Standard and Poor’s 500 Index (S&P 500), an unmanaged index of common stocks. The returns for each class of the Fund will differ from Investor shares because of the different expenses applicable to those share classes. The returns presented in the table for periods prior to the inception of the Class A, Institutional, and Class R shares reflect the performance of the Investor shares. Class A shares and Institutional shares commenced operations on November 28, 2008. Class R shares commenced operations on November 28, 2003. These returns have not been adjusted to take into account the lower expenses applicable to Class A, Institutional, and Class R shares, but for Class A shares, the returns in the table reflect a deduction for the maximum sales charge. Updated information on the Fund’s investment results can be obtained by visiting www.domini.com/performance or by calling 1-800-582-6757.

The Fund’s past results (before and after taxes) are not necessarily an indication of how the Fund will perform in the future.

Average Annual Total Return (%)

Calendar years ended December 31

Highest/lowest quarterly results during this time period were: 20.58% (quarter ended 6/30/09) and –24.04% (quarter ended 12/31/08). The Fund’s year-to-date results as of the most recent calendar quarter ended 9/30/12, were 14.31%.

Average annual total returns for periods ended December 31, 2011 (with maximum sales charge
for Class A shares)

Average Annual Total Returns Domini Social Equity Fund	1 Year	5 Years	10 Years
Investor	0.74%	(0.43%)	2.16%
Investor Return after taxes on distributions	0.66%	(0.70%)	1.92%
Investor Return after taxes on distributions and sale of shares	0.59%	(0.38%)	1.80%
Class A	(3.94%)	(1.40%)	1.66%
Institutional	1.12%	(0.43%)	2.16%
Class R	0.96%	(0.08%)	2.43%
S&P 500 (reflects no deduction for fees, expenses, or taxes)	2.11%	(0.25%)	2.92%

After-tax returns are shown only for Investor shares; after-tax returns for other share classes will vary. After-tax returns are calculated using the highest individual marginal federal income tax rates in effect during each year of the periods shown and do not reflect the impact of state and local taxes. Your actual after-tax returns depend on your individual tax situation and likely will differ from the results shown above. In addition, after-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as a 401(k) plan or individual retirement account (IRA).

[1] Paper document delivery fee applies to direct Fund accounts with balances below $10,000 and may be avoided by choosing e-delivery of Fund statements, prospectuses, and reports.

[2] /year

[1] The Fund's adviser has contractually agreed to waive certain fees and/or reimburse certain ordinary operating expenses in order to limit Investor, Class A, Institutional, and Class R share expenses to 1.25%, 1.18%, 0.80%, and 0.90%, respectively. The agreement expires on November 30, 2013, absent an earlier modification by the Fund's Board.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	DOMINI SOCIAL INVESTMENT TRUST
Prospectus Date	rr_ProspectusDate	Nov. 30, 2012
Domini International Social Equity Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Domini International Social Equity FundSM
Objective [Heading]	rr_ObjectiveHeading	Investment objective:
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund seeks to provide its shareholders with long-term total return.
Expense [Heading]	rr_ExpenseHeading	Fees and expenses of the Fund:
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for Class A sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in the Investor or Class A shares of each Domini Fund, except the Domini Social Bond Fund. More information about these and other discounts is available from your financial professional or in the Fund’s prospectus on page A-15 under the heading “How Sales Charges Are Calculated for Class A Shares” and in the Fund’s Statement of Additional Information (“SAI”) on page 32 under the heading “Additional Information Regarding Class A Sales Charges.”
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	Shareholder fees (paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	November 30, 2013
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio turnover:
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual Fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s turnover rate was 110% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	110.00%
Expense Breakpoint Discounts [Text]	rr_ExpenseBreakpointDiscounts	You may qualify for Class A sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in the Investor or Class A shares of each Domini Fund, except the Domini Social Bond Fund.
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	50,000
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated, that your investment has a 5% return each year, and that the Fund’s operating expenses (reflecting applicable contractual fee waivers and expense reimbursement arrangements) remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be as follows:
Expense Example by, Year, Caption [Text]	rr_ExpenseExampleByYearCaption	Share classes (whether or not shares are redeemed)
Expense Example, No Redemption, By Year, Caption [Text]	rr_ExpenseExampleNoRedemptionByYearCaption	Share classes (whether or not shares are redeemed)
Strategy [Heading]	rr_StrategyHeading	Principal investment strategies:
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	Under normal circumstances, the Fund primarily invests in the equity securities of mid- and large-capitalization companies located in Europe, the Asia-Pacific region, and throughout the rest of the world. The Fund’s investments will normally be tied economically to at least 10 different countries other than the U.S. Under normal circumstances, at least 80% of the Fund’s assets will be invested in equity securities and related investments with similar economic characteristics. The Fund will primarily invest in companies tied economically to developed market countries throughout the world (or equivalent shares such as ADRs or other securities representing underlying shares of foreign companies) but may invest up to 10% of its assets in companies tied economically to emerging-market countries. Domini evaluates the Fund’s potential investments against its social and environmental standards based on the businesses in which they engage, as well as on the quality of their relations with key stakeholders, including communities, customers, ecosystems, employees, investors, and suppliers. For additional information about the standards Domini uses to evaluate potential investments and the securities held by the Fund, and certain limitations on investments, please see “Socially Responsible Investing.” Domini reserves the right to alter its social and environmental standards or the application of those standards, or to add new standards, at any time without shareholder approval.
Risk [Heading]	rr_RiskHeading	Principal risks:
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	Risk is inherent in all investing. The value of your investment in the Fund, as well as the amount of return you receive on your investment, may fluctuate significantly in the short and long term. You may lose all or part of your investment in the Fund or your investment may not perform as well as other similar investments. The following is a summary description of certain risks of investing in the Fund. Country risk. The Fund expects to diversify its investments among issuers with significant exposure to various countries throughout the world but it may hold a large number of securities with exposure to a single country. Such exposure would increase the risk that economic, political, and social conditions in a country will have a significant impact on Fund performance. Currency risk. Fluctuations between the U.S. dollar and foreign currency exchange rates could negatively affect the value of the Fund’s investments. The Fund will benefit when foreign currencies strengthen against the dollar and will be hurt when foreign currencies weaken against the dollar. Currency exchange rates can be volatile and are affected by factors such as general economic conditions, the actions of U.S. and foreign governments or central banks, the imposition of currency controls or restrictions and speculation. Foreign Investing and Emerging Markets risk. Investments in foreign regions may be more volatile and less liquid than U.S. investments due to adverse political, social, and economic developments, such as nationalization or expropriation of assets, confiscatory taxation, and political or financial instability; regulatory differences, such as accounting, auditing, and financial reporting standards and practices; natural disasters; and the degree of government oversight and supervision. These risks may be heightened in connection with investments in emerging-market countries. Information risk. There is a risk that information used by the adviser to evaluate the social and environmental performance of issuers, industries, markets, sectors, and regions may not be readily available, complete, or accurate, which could negatively impact the adviser’s ability to apply its social and environmental standards, which may negatively impact Fund performance. This may lead the Fund to avoid investment in certain issuers, industries, markets, sectors, or regions. Market risk. The market prices of Fund securities may go up or down, sometimes rapidly or unpredictably, due to general market conditions, such as real or perceived adverse economic or political conditions, inflation, changes in interest rates, lack of liquidity in the markets, or adverse investor sentiment. When market prices fall, the value of your investment will go down. The financial crisis that began in 2008 caused a significant decline in the value and liquidity of many securities of issuers worldwide. Some government and non-governmental issuers (notably in Europe) have defaulted on, or been forced to restructure their debts, and many other issuers have faced difficulties in obtaining credit. These market conditions may continue to worsen or spread, including in the U.S., Europe, and beyond. Further defaults or restructurings of their debt by governments and others could have additional adverse effects on economies, financial markets, and asset valuations around the world. Whether or not the Fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, these events could negatively affect the value and liquidity of the Fund’s investments. Legislation recently enacted in the U.S. calls for changes in many aspects of financial regulation. The impact of the legislation on the markets, and the practical implications for market participants, may not be fully known for some time. Mid-to Large-Cap Companies risk. The market prices of companies at different capitalization levels may go up or down due to general market conditions and cycles. The value of your investment will be affected by the Fund’s exposure to mid- and large-cap companies. Sector Concentration risk. The Fund may hold a large percentage of securities in a single sector (e.g., financials). If the Fund holds a large percentage of securities in a single sector, its performance will be tied closely to and affected by the performance of that sector. Socially Responsible Investing risk. The application of the adviser’s social and environmental standards will affect the Fund’s exposure to certain issuers, industries, sectors, regions, and countries and may impact the relative financial performance of the Fund — positively or negatively — depending on whether such investments are in or out of favor. Style risk. The value of your investment may decrease if the subadviser’s quantitative investment approach does not respond well to current market conditions or its judgment regarding the quality, value, or market trends affecting a particular security, industry, sector, or region is incorrect. The submanager’s quantitative model relies upon a complex software system, and failure of the system to function or the presence of software errors could have an adverse impact on the value of Fund performance. These and other risks are discussed in more detail later in this prospectus or in the SAI. Please note that there are many other factors that could adversely affect your investment and that could prevent the Fund from achieving its goals.
Risk Lose Money [Text]	rr_RiskLoseMoney	You may lose all or part of your investment in the Fund or your investment may not perform as well as other similar investments.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Investment results:
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year for Investor shares and by showing how the Fund’s average annual total returns for 1, 5, and 10 years, as applicable, compare with those of a broad measure of market performance, the Morgan Stanley Capital International Europe, Australasia, and Far East Index (MSCI EAFE), a free float-adjusted market capitalization weighted index that is designed to measure the equity market performance of developed markets, excluding the U.S. and Canada. The returns for each class of the Fund will differ from Investor shares because of the different expenses applicable to those share classes. The Class A returns presented in the table for periods prior to the November 28, 2008, inception of the Class A shares reflect the performance of the Investor shares. Such returns have not been adjusted to take into account the lower expenses applicable to Class A shares, but in the table have been adjusted to reflect a deduction for the maximum sales charge. Because Institutional shares were not offered prior to November 30, 2012, no performance information is shown for such shares. Updated information on the Fund’s investment results can be obtained by visiting www.domini.com/performance and by calling 1-800-582-6757. The Fund’s past results (before and after taxes) are not necessarily an indication of how the Fund will perform in the future.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year for Investor shares and by showing how the Fund’s average annual total returns for 1, 5, and 10 years, as applicable, compare with those of a broad measure of market performance, the Morgan Stanley Capital International Europe, Australasia, and Far East Index (MSCI EAFE), a free float-adjusted market capitalization weighted index that is designed to measure the equity market performance of developed markets, excluding the U.S. and Canada.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	1-800-582-6757
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.domini.com/performance
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	The Fund’s past results (before and after taxes) are not necessarily an indication of how the Fund will perform in the future.
Bar Chart [Heading]	rr_BarChartHeading	Average Annual Total Return (%)
Bar Chart Footnotes [Text Block]	rr_BarChartFootnotesTextBlock	Calendar years ended December 31
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Highest/Lowest quarterly results during this time period were: 27.64% (quarter ended 6/30/09) and –23.40% (quarter ended 12/31/08). The Fund’s year-to-date results as of the most recent calendar quarter ended 9/30/12, were 12.72%.
Performance Table Heading	rr_PerformanceTableHeading	Average annual total returns for periods ended December 31, 2011 (with maximum sales charge for Class A shares)
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	After-tax returns are calculated using the highest individual marginal federal income tax rates in effect during each year of the periods shown and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	Your actual after-tax returns depend on your individual tax situation and likely will differ from the results shown above. In addition, after-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as a 401(k) plan or individual retirement account (IRA).
Performance Table One Class of after Tax Shown [Text]	rr_PerformanceTableOneClassOfAfterTaxShown	After-tax returns are shown only for Investor shares; after-tax returns for other share classes will vary.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	After-tax returns are shown only for Investor shares; after-tax returns for other share classes will vary. After-tax returns are calculated using the highest individual marginal federal income tax rates in effect during each year of the periods shown and do not reflect the impact of state and local taxes. Your actual after-tax returns depend on your individual tax situation and likely will differ from the results shown above. In addition, after-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as a 401(k) plan or individual retirement account (IRA).
Domini International Social Equity Fund | Investor
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases as a percentage of offering price	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Redemption fee on shares held less than 30 days (as a percentage of amount redeemed, if applicable)	rr_RedemptionFeeOverRedemption	2.00%
Paper document delivery fee (choose e-delivery to avoid this fee)	rr_MaximumAccountFee	15	[1],[2]
Management fees	rr_ManagementFeesOverAssets	1.00%
Distribution (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses	rr_OtherExpensesOverAssets	0.49%	[3]
Total annual Fund operating expenses	rr_ExpensesOverAssets	1.74%
Fee waiver and expense reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.14%)	[4]
Total annual Fund operating expenses after fee waiver and expense reimbursements	rr_NetExpensesOverAssets	1.60%
1 Year	rr_ExpenseExampleYear01	163
3 Years	rr_ExpenseExampleYear03	534
5 Years	rr_ExpenseExampleYear05	931
10 Years	rr_ExpenseExampleYear10	2,040
1 Year	rr_ExpenseExampleNoRedemptionYear01	163
3 Years	rr_ExpenseExampleNoRedemptionYear03	534
5 Years	rr_ExpenseExampleNoRedemptionYear05	931
10 Years	rr_ExpenseExampleNoRedemptionYear10	2,040
2007	rr_AnnualReturn2007	2.22%
2008	rr_AnnualReturn2008	(46.65%)
2009	rr_AnnualReturn2009	28.68%
2010	rr_AnnualReturn2010	11.25%
2011	rr_AnnualReturn2011	(13.45%)
Year to Date Return, Label	rr_YearToDateReturnLabel	year-to-date
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Sep. 30, 2012
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	12.72%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	27.64%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(23.40%)
1 Year	rr_AverageAnnualReturnYear01	(13.45%)
5 Year	rr_AverageAnnualReturnYear05	(7.54%)
Since Inception	rr_AverageAnnualReturnSinceInception	(7.54%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 27, 2006
Domini International Social Equity Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases as a percentage of offering price	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	4.75%
Redemption fee on shares held less than 30 days (as a percentage of amount redeemed, if applicable)	rr_RedemptionFeeOverRedemption	2.00%
Paper document delivery fee (choose e-delivery to avoid this fee)	rr_MaximumAccountFee	15	[1],[2]
Management fees	rr_ManagementFeesOverAssets	1.00%
Distribution (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses	rr_OtherExpensesOverAssets	1.08%	[3]
Total annual Fund operating expenses	rr_ExpensesOverAssets	2.33%
Fee waiver and expense reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.76%)	[4]
Total annual Fund operating expenses after fee waiver and expense reimbursements	rr_NetExpensesOverAssets	1.57%
1 Year	rr_ExpenseExampleYear01	627
3 Years	rr_ExpenseExampleYear03	1,099
5 Years	rr_ExpenseExampleYear05	1,595
10 Years	rr_ExpenseExampleYear10	2,959
1 Year	rr_ExpenseExampleNoRedemptionYear01	627
3 Years	rr_ExpenseExampleNoRedemptionYear03	1,099
5 Years	rr_ExpenseExampleNoRedemptionYear05	1,595
10 Years	rr_ExpenseExampleNoRedemptionYear10	2,959
1 Year	rr_AverageAnnualReturnYear01	(17.60%)
5 Year	rr_AverageAnnualReturnYear05	(8.43%)
Since Inception	rr_AverageAnnualReturnSinceInception	(8.43%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 27, 2006
Domini International Social Equity Fund | Institutional
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases as a percentage of offering price	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Redemption fee on shares held less than 30 days (as a percentage of amount redeemed, if applicable)	rr_RedemptionFeeOverRedemption	2.00%
Paper document delivery fee (choose e-delivery to avoid this fee)	rr_MaximumAccountFee	15	[1],[2]
Management fees	rr_ManagementFeesOverAssets	1.00%
Distribution (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.27%	[3]
Total annual Fund operating expenses	rr_ExpensesOverAssets	1.27%
Fee waiver and expense reimbursements	rr_FeeWaiverOrReimbursementOverAssets	none	[4]
Total annual Fund operating expenses after fee waiver and expense reimbursements	rr_NetExpensesOverAssets	1.27%
1 Year	rr_ExpenseExampleYear01	129
3 Years	rr_ExpenseExampleYear03	403
5 Years	rr_ExpenseExampleYear05	697
10 Years	rr_ExpenseExampleYear10	1,534
1 Year	rr_ExpenseExampleNoRedemptionYear01	129
3 Years	rr_ExpenseExampleNoRedemptionYear03	403
5 Years	rr_ExpenseExampleNoRedemptionYear05	697
10 Years	rr_ExpenseExampleNoRedemptionYear10	1,534
Domini International Social Equity Fund | Return after taxes on distributions | Investor
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(14.55%)
5 Year	rr_AverageAnnualReturnYear05	(7.93%)
Since Inception	rr_AverageAnnualReturnSinceInception	(7.92%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 27, 2006
Domini International Social Equity Fund | Return after taxes on distributions and sale of shares | Investor
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(7.78%)
5 Year	rr_AverageAnnualReturnYear05	(6.13%)
Since Inception	rr_AverageAnnualReturnSinceInception	(6.12%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 27, 2006
Domini International Social Equity Fund | MSCI EAFE (reflects no deduction for fees, expenses, or taxes)
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(11.73%)
5 Year	rr_AverageAnnualReturnYear05	(4.26%)
Since Inception	rr_AverageAnnualReturnSinceInception	(4.06%)

[1] Paper document delivery fee applies to direct Fund accounts with balances below $10,000 and may be avoided by choosing e-delivery of Fund statements, prospectuses, and reports.

[2] /year

[3] Other miscellaneous expenses for Institutional shares are based on estimated amounts for the current fiscal year.

[4] The Fund's adviser has contractually agreed to waive certain fees and/or reimburse certain ordinary operating expenses in order to limit Investor, Class A, and Institutional share expenses to 1.60%, 1.57%, and 1.27%, respectively. The agreement expires on November 30, 2013, absent an earlier modification by the Fund's Board.

XML

Document and Entity Information	12 Months Ended
	Nov. 30, 2012
Risk/Return:
Document Type	485BPOS
Document Period End Date	Jul. 31, 2012
Registrant Name	DOMINI SOCIAL INVESTMENT TRUST
Central Index Key	0000851680
Amendment Flag	false
Document Creation Date	Nov. 28, 2012
Document Effective Date	Nov. 30, 2012
Prospectus Date	Nov. 30, 2012

XML

Domini Social Bond Fund

DOMINI SOCIAL BOND FUND^®

Investment objective:

The Fund seeks to provide its shareholders with a high level of current income and total return.

Fees and expenses of the Fund:

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

Shareholder fees (paid directly from your investment)

Shareholder Fees Domini Social Bond Fund (USD $)		Investor	Institutional
Redemption fee on shares held less than 30 days (as a percentage of amount redeemed, if applicable)		2.00%	2.00%
Paper document delivery fee (choose e-delivery to avoid this fee)	[1][2]	15	15

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

Annual Fund Operating Expenses Domini Social Bond Fund		Investor	Institutional
Management fees		0.40%	0.40%
Distribution (12b-1) fees		0.25%	none
Administrative services fee		0.25%	0.25%
Other miscellaneous expenses		0.38%	3.34%
Total other expenses		0.63%	3.59%
Total annual Fund operating expenses		1.28%	3.99%
Fee waivers and expense reimbursements	[1]	(0.33%)	(3.34%)
Total annual Fund operating expenses after fee waivers and expense reimbursements		0.95%	0.65%

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated, that your investment has a 5% return each year, and that the Fund’s operating expenses (reflecting applicable contractual fee waivers and expense reimbursement arrangements) remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be as follows:

Share classes (whether or not shares are redeemed)

Expense Example Domini Social Bond Fund (USD $)	1 Year	3 Years	5 Years	10 Years
Investor	97	373	671	1,516
Institutional	66	908	1,766	3,988

Share classes (whether or not shares are redeemed)

Expense Example, No Redemption Domini Social Bond Fund (USD $)	1 Year	3 Years	5 Years	10 Years
Investor	97	373	671	1,516
Institutional	66	908	1,766	3,988

Portfolio turnover:

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual Fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 126% of the average value of its portfolio.

Principal investment strategies:

Under normal circumstances, the Fund invests at least 85% of its assets in investment-grade securities and maintains a dollar-weighted average effective maturity of between two and ten years. Under normal circumstances, at least 80% of the Fund’s assets will be invested in bonds, including government and corporate bonds, mortgage-backed and asset-backed securities, and U.S. dollar denominated bonds issued by non-U.S. entities. Some of these instruments may not be insured and may earn below-market rates of return. Some investments may be unrated, lower-rated, or illiquid securities. Domini evaluates the Fund’s potential corporate debt instruments against its social and environmental standards based on the businesses in which they engage, as well as on the quality of their relations with key stakeholders, including communities, customers, ecosystems, employees, investors, and suppliers. For noncorporate issuers, Domini seeks to identify investments with a positive impact on communities. For additional information about the standards Domini uses to evaluate potential investments and the securities held by the Fund, and certain limitations on investment, please see “Socially Responsible Investing.” Domini reserves the right to alter its social and environmental standards or the application of those standards, or to add new standards, at any time without shareholder approval.

Principal risks:

Risk is inherent in all investing. The value of your investment in the Fund, as well as the amount of return you receive on your investment, may fluctuate significantly in the short and long term. You may lose all or part of your investment in the Fund or your investment may not perform as well as other similar investments. The following is a summary description of certain risks of investing in the Fund.

• Credit risk. Fixed-income securities are subject to credit risk. Credit risk is the possibility that an issuer will fail to make timely payments of interest or principal, or go bankrupt. The lower the ratings of such debt securities, the greater their risks. In addition, lower-rated securities have higher risk characteristics, and changes in economic conditions are likely to cause issuers of these securities to be unable to meet their obligations. Below investment grade securities (sometimes referred to as “junk bonds”) involve greater risk of default or downgrade and are more volatile than investment grade securities. Below investment grade securities may also be less liquid than higher-quality securities.

• Government-Sponsored Entities risk. The Fund’s investments in securities issued by government-sponsored entities such as Fannie Mae, Freddie Mac, and the Federal Home Loan Bank are not guaranteed or insured by the U.S. government and may decline in value.

• Information risk. There is a risk that information used by the adviser to evaluate the social and environmental performance of issuers, industries, markets, and sectors, may not be readily available, complete, or accurate, which could negatively impact the adviser’s ability to apply its social and environmental standards which may negatively impact Fund performance. This may also lead the Fund to avoid investment in certain issuers, industries, markets, or sectors.

• Interest Rate risk. The value of your investment will fluctuate with interest rates. If interest rates rise, the price of a fixed-income security declines and could reduce the value of the Fund’s share price. A rise in rates tends to have a greater impact on securities with longer maturities or higher durations.

• Liquidity risk. Some securities held by the Fund may be difficult to sell, or may be illiquid, particularly during times of market turmoil. Illiquid securities also may be difficult to value. Due to limitations on investments in illiquid securities the Fund may be unable to achieve its desired level of exposure to certain sectors. If the Fund is forced to sell an illiquid asset to meet redemption request or other cash needs, the Fund may be forced to sell such securities at a loss.

• Market risk. The market prices of Fund securities may go up or down, sometimes rapidly or unpredictably, due to general market conditions, such as real or perceived adverse economic or political conditions, inflation, changes in interest rates, lack of liquidity in the markets, or adverse investor sentiment. When market prices fall, the value of your investment will go down. The financial crisis that began in 2008 caused a significant decline in the value and liquidity of many securities of issuers worldwide. Some government and non-governmental issuers (notably in Europe) have defaulted on, or been forced to restructure their debts, and many other issuers have faced difficulties in obtaining credit. These market conditions may continue to worsen or spread, including in the U.S., Europe, and beyond. Further defaults or restructurings of their debt by governments and others could have additional adverse effects on economies, financial markets, and asset valuations around the world. Whether or not the Fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, these events could negatively affect the value and liquidity of the Fund’s investments. Legislation recently enacted in the U.S. calls for changes in many aspects of financial regulation. The impact of the legislation on the markets, and the practical implications for market participants, may not be fully known for some time.

• Prepayment and Extension risk. Many issuers have a right to prepay their securities. If interest rates fall, an issuer may exercise this right. If this happens, the Fund will be forced to reinvest prepayment proceeds at a time when yields on securities available in the market are lower than the yield on the prepaid security. The Fund also may lose any premium it paid on the security. If interest rates rise, repayments of fixed-income securities may occur more slowly than anticipated by the market. This may drive the prices of these securities down because their interest rates are lower than the current interest rate and they remain outstanding longer.

• Socially Responsible Investing risk. The application of the adviser’s social and environmental standards will affect the Fund’s exposure to certain issuers, industries, and sectors and may impact the relative financial performance of the Fund — positively or negatively — depending on whether such investments are in or out of favor.

These and other risks are discussed in more detail later in this prospectus or in the SAI. Please note that there are many other factors that could adversely affect your investment and that could prevent the Fund from achieving its goals.

Investment results:

The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and by showing how the Fund’s average annual total returns for 1, 5, and 10 years, as applicable, compare with those of a broad measure of market performance, the Barclays Capital Intermediate Aggregate Index (BCIA), an unmanaged index of intermediate investment-grade fixed-income securities. The returns for each class of the Fund will differ from Investor shares because of the different expenses applicable to those share classes. The returns presented in the table for periods prior to the inception of the Institutional shares reflect the performance of the Investor shares. Institutional shares commenced operations on November 30, 2011. These returns have not been adjusted to take into account the lower expenses applicable to Institutional shares. Updated information on the Fund’s investment results can be obtained by visiting www.domini.com/performance and by calling 1-800-582-6757.

The Fund’s past results (before and after taxes) are not necessarily an indication of how the Fund will perform in the future.

Average Annual Total Return (%)

Calendar years ended December 31

Highest/lowest quarterly results during this time period were: 4.49% (quarter ended 12/31/08) and –2.58% (quarter ended 06/30/04). The Fund’s year-to-date results as of the most recent calendar quarter ended 9/30/12, were 2.61%.

Average annual total returns for periods ended December 31, 2011

Average Annual Total Returns Domini Social Bond Fund	1 Year	5 Years	10 Years
Investor shares	5.85%	5.61%	4.68%
Investor shares Return after taxes on distributions	4.39%	4.23%	3.30%
Investor shares Return after taxes on distributions and sale of shares	4.15%	4.04%	3.22%
Institutional shares	5.85%	5.61%	4.68%
BCIA (reflects no deduction for fees, expenses, or taxes)	5.97%	6.09%	5.39%

After-tax returns are shown only for Investor shares; after-tax returns for other share classes will vary. After-tax returns are calculated using the highest individual marginal federal income tax rates in effect during each year of the periods shown and do not reflect the impact of state and local taxes. Your actual after-tax returns depend on your individual tax situation and likely will differ from the results shown above. In addition, after-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as a 401(k) plan or individual retirement account (IRA).

[1] Paper document delivery fee applies to direct Fund accounts with balances below $10,000 and may be avoided by choosing e-delivery of Fund statements, prospectuses, and reports.

[2] /year

[1] The Fund's adviser has contractually agreed to waive certain fees and/or reimburse certain ordinary operating expenses in order to limit Investor and Institutional share expenses to 0.95% and 0.65%, respectively. The agreement expires on November 30, 2013, absent an earlier modification by the Fund's Board.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	DOMINI SOCIAL INVESTMENT TRUST
Prospectus Date	rr_ProspectusDate	Nov. 30, 2012
Document Creation Date	dei_DocumentCreationDate	Nov. 28, 2012

XML

Domini International Social Equity Fund

Domini International Social Equity Fund^SM

Investment objective:

The Fund seeks to provide its shareholders with long-term total return.

Fees and expenses of the Fund:

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for Class A sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in the Investor or Class A shares of each Domini Fund, except the Domini Social Bond Fund. More information about these and other discounts is available from your financial professional or in the Fund’s prospectus on page A-15 under the heading “How Sales Charges Are Calculated for Class A Shares” and in the Fund’s Statement of Additional Information (“SAI”) on page 32 under the heading “Additional Information Regarding Class A Sales Charges.”

Shareholder fees (paid directly from your investment)

Shareholder Fees Domini International Social Equity Fund (USD $)		Investor	Class A	Institutional
Maximum sales charge (load) imposed on purchases as a percentage of offering price		none	4.75%	none
Redemption fee on shares held less than 30 days (as a percentage of amount redeemed, if applicable)		2.00%	2.00%	2.00%
Paper document delivery fee (choose e-delivery to avoid this fee)	[1][2]	15	15	15

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

Annual Fund Operating Expenses Domini International Social Equity Fund		Investor	Class A	Institutional
Management fees		1.00%	1.00%	1.00%
Distribution (12b-1) fees		0.25%	0.25%	none
Other expenses	[1]	0.49%	1.08%	0.27%
Total annual Fund operating expenses		1.74%	2.33%	1.27%
Fee waiver and expense reimbursements	[2]	(0.14%)	(0.76%)	none
Total annual Fund operating expenses after fee waiver and expense reimbursements		1.60%	1.57%	1.27%

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated, that your investment has a 5% return each year, and that the Fund’s operating expenses (reflecting applicable contractual fee waivers and expense reimbursement arrangements) remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be as follows:

Share classes (whether or not shares are redeemed)

Expense Example Domini International Social Equity Fund (USD $)	1 Year	3 Years	5 Years	10 Years
Investor	163	534	931	2,040
Class A	627	1,099	1,595	2,959
Institutional	129	403	697	1,534

Share classes (whether or not shares are redeemed)

Expense Example, No Redemption Domini International Social Equity Fund (USD $)	1 Year	3 Years	5 Years	10 Years
Investor	163	534	931	2,040
Class A	627	1,099	1,595	2,959
Institutional	129	403	697	1,534

Portfolio turnover:

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual Fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s turnover rate was 110% of the average value of its portfolio.

Principal investment strategies:

Under normal circumstances, the Fund primarily invests in the equity securities of mid- and large-capitalization companies located in Europe, the Asia-Pacific region, and throughout the rest of the world. The Fund’s investments will normally be tied economically to at least 10 different countries other than the U.S. Under normal circumstances, at least 80% of the Fund’s assets will be invested in equity securities and related investments with similar economic characteristics. The Fund will primarily invest in companies tied economically to developed market countries throughout the world (or equivalent shares such as ADRs or other securities representing underlying shares of foreign companies) but may invest up to 10% of its assets in companies tied economically to emerging-market countries. Domini evaluates the Fund’s potential investments against its social and environmental standards based on the businesses in which they engage, as well as on the quality of their relations with key stakeholders, including communities, customers, ecosystems, employees, investors, and suppliers. For additional information about the standards Domini uses to evaluate potential investments and the securities held by the Fund, and certain limitations on investments, please see “Socially Responsible Investing.” Domini reserves the right to alter its social and environmental standards or the application of those standards, or to add new standards, at any time without shareholder approval.

Principal risks:

Risk is inherent in all investing. The value of your investment in the Fund, as well as the amount of return you receive on your investment, may fluctuate significantly in the short and long term. You may lose all or part of your investment in the Fund or your investment may not perform as well as other similar investments. The following is a summary description of certain risks of investing in the Fund.

• Country risk. The Fund expects to diversify its investments among issuers with significant exposure to various countries throughout the world but it may hold a large number of securities with exposure to a single country. Such exposure would increase the risk that economic, political, and social conditions in a country will have a significant impact on Fund performance.

• Currency risk. Fluctuations between the U.S. dollar and foreign currency exchange rates could negatively affect the value of the Fund’s investments. The Fund will benefit when foreign currencies strengthen against the dollar and will be hurt when foreign currencies weaken against the dollar. Currency exchange rates can be volatile and are affected by factors such as general economic conditions, the actions of U.S. and foreign governments or central banks, the imposition of currency controls or restrictions and speculation.

• Foreign Investing and Emerging Markets risk. Investments in foreign regions may be more volatile and less liquid than U.S. investments due to adverse political, social, and economic developments, such as nationalization or expropriation of assets, confiscatory taxation, and political or financial instability; regulatory differences, such as accounting, auditing, and financial reporting standards and practices; natural disasters; and the degree of government oversight and supervision. These risks may be heightened in connection with investments in emerging-market countries.

• Information risk. There is a risk that information used by the adviser to evaluate the social and environmental performance of issuers, industries, markets, sectors, and regions may not be readily available, complete, or accurate, which could negatively impact the adviser’s ability to apply its social and environmental standards, which may negatively impact Fund performance. This may lead the Fund to avoid investment in certain issuers, industries, markets, sectors, or regions.

• Market risk. The market prices of Fund securities may go up or down, sometimes rapidly or unpredictably, due to general market conditions, such as real or perceived adverse economic or political conditions, inflation, changes in interest rates, lack of liquidity in the markets, or adverse investor sentiment. When market prices fall, the value of your investment will go down. The financial crisis that began in 2008 caused a significant decline in the value and liquidity of many securities of issuers worldwide. Some government and non-governmental issuers (notably in Europe) have defaulted on, or been forced to restructure their debts, and many other issuers have faced difficulties in obtaining credit. These market conditions may continue to worsen or spread, including in the U.S., Europe, and beyond. Further defaults or restructurings of their debt by governments and others could have additional adverse effects on economies, financial markets, and asset valuations around the world. Whether or not the Fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, these events could negatively affect the value and liquidity of the Fund’s investments. Legislation recently enacted in the U.S. calls for changes in many aspects of financial regulation. The impact of the legislation on the markets, and the practical implications for market participants, may not be fully known for some time.

• Mid-to Large-Cap Companies risk. The market prices of companies at different capitalization levels may go up or down due to general market conditions and cycles. The value of your investment will be affected by the Fund’s exposure to mid- and large-cap companies.

• Sector Concentration risk. The Fund may hold a large percentage of securities in a single sector (e.g., financials). If the Fund holds a large percentage of securities in a single sector, its performance will be tied closely to and affected by the performance of that sector.

• Socially Responsible Investing risk. The application of the adviser’s social and environmental standards will affect the Fund’s exposure to certain issuers, industries, sectors, regions, and countries and may impact the relative financial performance of the Fund — positively or negatively — depending on whether such investments are in or out of favor.

• Style risk. The value of your investment may decrease if the subadviser’s quantitative investment approach does not respond well to current market conditions or its judgment regarding the quality, value, or market trends affecting a particular security, industry, sector, or region is incorrect. The submanager’s quantitative model relies upon a complex software system, and failure of the system to function or the presence of software errors could have an adverse impact on the value of Fund performance.

These and other risks are discussed in more detail later in this prospectus or in the SAI. Please note that there are many other factors that could adversely affect your investment and that could prevent the Fund from achieving its goals.

Investment results:

The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year for Investor shares and by showing how the Fund’s average annual total returns for 1, 5, and 10 years, as applicable, compare with those of a broad measure of market performance, the Morgan Stanley Capital International Europe, Australasia, and Far East Index (MSCI EAFE), a free float-adjusted market capitalization weighted index that is designed to measure the equity market performance of developed markets, excluding the U.S. and Canada. The returns for each class of the Fund will differ from Investor shares because of the different expenses applicable to those share classes. The Class A returns presented in the table for periods prior to the November 28, 2008, inception of the Class A shares reflect the performance of the Investor shares. Such returns have not been adjusted to take into account the lower expenses applicable to Class A shares, but in the table have been adjusted to reflect a deduction for the maximum sales charge. Because Institutional shares were not offered prior to November 30, 2012, no performance information is shown for such shares. Updated information on the Fund’s investment results can be obtained by visiting www.domini.com/performance and by calling 1-800-582-6757.

The Fund’s past results (before and after taxes) are not necessarily an indication of how the Fund will perform in the future.

Average Annual Total Return (%)

Calendar years ended December 31

Highest/Lowest quarterly results during this time period were: 27.64% (quarter ended 6/30/09) and –23.40% (quarter ended 12/31/08). The Fund’s year-to-date results as of the most recent calendar quarter ended 9/30/12, were 12.72%.

Average annual total returns for periods ended December 31, 2011 (with maximum sales charge
for Class A shares)

Average Annual Total Returns Domini International Social Equity Fund	1 Year	5 Year	Since Inception	Inception Date
Investor Shares:	(13.45%)	(7.54%)	(7.54%)	Dec. 27, 2006
Investor Shares: Return after taxes on distributions	(14.55%)	(7.93%)	(7.92%)	Dec. 27, 2006
Investor Shares: Return after taxes on distributions and sale of shares	(7.78%)	(6.13%)	(6.12%)	Dec. 27, 2006
Class A Shares	(17.60%)	(8.43%)	(8.43%)	Dec. 27, 2006
MSCI EAFE (reflects no deduction for fees, expenses, or taxes)	(11.73%)	(4.26%)	(4.06%)

After-tax returns are shown only for Investor shares; after-tax returns for other share classes will vary. After-tax returns are calculated using the highest individual marginal federal income tax rates in effect during each year of the periods shown and do not reflect the impact of state and local taxes. Your actual after-tax returns depend on your individual tax situation and likely will differ from the results shown above. In addition, after-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as a 401(k) plan or individual retirement account (IRA).

[1] Paper document delivery fee applies to direct Fund accounts with balances below $10,000 and may be avoided by choosing e-delivery of Fund statements, prospectuses, and reports.

[2] /year

[1] Other miscellaneous expenses for Institutional shares are based on estimated amounts for the current fiscal year.

[2] The Fund's adviser has contractually agreed to waive certain fees and/or reimburse certain ordinary operating expenses in order to limit Investor, Class A, and Institutional share expenses to 1.60%, 1.57%, and 1.27%, respectively. The agreement expires on November 30, 2013, absent an earlier modification by the Fund's Board.