Risk/Return Summary - FidelitySAISustainableInternationalEquityEmergingMarketsEquityFunds-ComboPRO - FidelitySAISustainableInternationalEquityEmergingMarketsEquityFunds-ComboPRO - Fidelity SAI Sustainable International Equity Fund	Dec. 30, 2022
Risk/Return:
Risk/Return [Heading]	Fund Summary Fund: Fidelity® SAI Sustainable International Equity Fund
Objective [Heading]	Investment Objective
Objective, Primary [Text Block]	Fidelity® SAI Sustainable International Equity Fund seeks long-term growth of capital.
Expense [Heading]	Fee Table
Expense Narrative [Text Block]	The following table describes the fees and expenses that may be incurred when you buy and hold shares of the fund.
Shareholder Fees Caption [Text]	Shareholder fees
Operating Expenses Caption [Text]	Annual Operating Expenses
Expense Example Narrative [Text Block]	This example helps compare the cost of investing in the fund with the cost of investing in other funds.Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:
Portfolio Turnover [Heading]	Portfolio Turnover
Portfolio Turnover [Text Block]	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 operating expenses or in the example, affect the fund's performance. For the period from April 14, 2022 to October 31, 2022, the fund's portfolio turnover rate was 51 % (annualized) of the average value of its portfolio.
Strategy [Heading]	Principal Investment Strategies
Strategy Narrative [Text Block]	Normally investing at least 80% of assets in equity securities of companies that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices based on an evaluation of such companies' individual environmental, social, and governance (ESG) profile. Normally investing primarily in non-U.S. securities. Using the Adviser's proprietary ESG ratings process to evaluate the current state of an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and also provide a qualitative forward-looking assessment of an issuer's sustainability outlook provided by the Adviser's fundamental research analysts and ESG team. The Adviser's ESG ratings of issuers are derived from multiple factors, including an issuer's environmental profile, which may include, but is not limited to, carbon and toxic emissions, water management, waste management, vulnerability to the physical impacts of climate change, and research and investment into products, services, and energies that reduce emissions and/or provide opportunities to transition to less carbon-intensive products or operations. An assessment of an issuer's social profile includes, but is not limited to, its approach to diversity and inclusion, human capital management, data privacy, product safety and human rights. With respect to governance, the independence and diversity of an issuer's board, its compensation practices and board oversight of critical ESG issues are considered as part of the assessment. These factors are weighted based on how material the Adviser believes each factor is to an issuer's financial outlook, and not all factors may be applicable to all issuers. Investing in issuers that the Adviser believes deliver tangible environmental or social impact through core business operations. An assessment of the impact characteristics of an issuer may involve corporate engagement and an analysis of issuer alignment with the United Nations Sustainable Development Goals using qualitative analysis as well as proprietary or third-party data. For example, issuers that provide access to clean water, education, or clean energy through their core business may be considered to deliver tangible impact. Allocating investments across different countries and regions. In addition to the ESG ratings process, using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments. Employing sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Sustainable Investing Exclusions" for additional information.
Risk [Heading]	Principal Investment Risks
Risk Narrative [Text Block]	Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments. Sustainability Risk. Application of FMR's ESG ratings process and/or its sustainable investing exclusion criteria may affect the fund's exposure to certain issuers, sectors, regions, and countries and may affect the fund's performance depending on whether certain investments are in or out of favor. The criteria related to the fund's ESG ratings process and/or adherence to its sustainable investing exclusion criteria may result in the fund forgoing opportunities to buy certain securities when it might otherwise be advantageous to do so, or selling securities for ESG reasons when it might be otherwise disadvantageous for it to do so. As a result, the fund's performance may at times be better or worse than the performance of funds that do not use ESG or sustainability criteria. There are significant differences in interpretations of what it means for an issuer to have positive ESG factors. While the Adviser believes its definitions are reasonable, the portfolio decisions it makes may differ with other investors' or advisers' views. When evaluating an issuer, the Adviser is dependent on information or data obtained through voluntary or third-party reporting that may be incomplete, inaccurate, or unavailable, which could cause the Adviser to incorrectly assess an issuer's business practices. Foreign Exposure. Foreign markets, particularly emerging markets, can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. The extent of economic development; political stability; market depth, infrastructure, and capitalization; and regulatory oversight can be less than in more developed markets. Emerging markets typically have less established legal, accounting and financial reporting systems than those in more developed markets, which may reduce the scope or quality of financial information available to investors. Emerging markets can be subject to greater social, economic, regulatory, and political uncertainties and can be extremely volatile. Foreign exchange rates also can be extremely volatile. Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. Management Risk The Adviser's application of the fund's strategy criteria may not achieve its intended results. The fund could underperform in comparison to other funds with a similar benchmark or similar objectives and investment strategies . An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency . You could lose money by investing in the fund.
Bar Chart and Performance Table [Heading]	Performance
Performance Narrative [Text Block]	Performance history will be available for the fund after the fund has been in operation for one calendar year.

Risk/Return Summary - FidelitySAISustainableInternationalEquityEmergingMarketsEquityFunds-ComboPRO - FidelitySAISustainableInternationalEquityEmergingMarketsEquityFunds-ComboPRO - Fidelity SAI Sustainable International Equity Fund

Dec. 30, 2022

Risk/Return:

Fund Summary Fund: Fidelity® SAI Sustainable International Equity Fund

Objective [Heading]

Investment Objective

Objective, Primary [Text Block]

Fidelity® SAI Sustainable International Equity Fund seeks long-term growth of capital.

Expense [Heading]

Fee Table

Expense Narrative [Text Block]

The following table describes the fees and expenses that may be incurred when you buy and hold shares of the fund.

Shareholder Fees Caption [Text]

Shareholder fees

Operating Expenses Caption [Text]

Annual Operating Expenses

Expense Example Narrative [Text Block]

This example helps compare the cost of investing in the fund with the cost of investing in other funds.Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:

Portfolio Turnover [Heading]

Portfolio Turnover

Portfolio Turnover [Text Block]

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 operating expenses or in the example, affect the fund's performance. For the period from April 14, 2022 to October 31, 2022, the fund's portfolio turnover rate was 51 % (annualized) of the average value of its portfolio.

Strategy [Heading]

Principal Investment Strategies

Strategy Narrative [Text Block]

Normally investing at least 80% of assets in equity securities of companies that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices based on an evaluation of such companies' individual environmental, social, and governance (ESG) profile. Normally investing primarily in non-U.S. securities. Using the Adviser's proprietary ESG ratings process to evaluate the current state of an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and also provide a qualitative forward-looking assessment of an issuer's sustainability outlook provided by the Adviser's fundamental research analysts and ESG team. The Adviser's ESG ratings of issuers are derived from multiple factors, including an issuer's environmental profile, which may include, but is not limited to, carbon and toxic emissions, water management, waste management, vulnerability to the physical impacts of climate change, and research and investment into products, services, and energies that reduce emissions and/or provide opportunities to transition to less carbon-intensive products or operations. An assessment of an issuer's social profile includes, but is not limited to, its approach to diversity and inclusion, human capital management, data privacy, product safety and human rights. With respect to governance, the independence and diversity of an issuer's board, its compensation practices and board oversight of critical ESG issues are considered as part of the assessment. These factors are weighted based on how material the Adviser believes each factor is to an issuer's financial outlook, and not all factors may be applicable to all issuers. Investing in issuers that the Adviser believes deliver tangible environmental or social impact through core business operations. An assessment of the impact characteristics of an issuer may involve corporate engagement and an analysis of issuer alignment with the United Nations Sustainable Development Goals using qualitative analysis as well as proprietary or third-party data. For example, issuers that provide access to clean water, education, or clean energy through their core business may be considered to deliver tangible impact. Allocating investments across different countries and regions. In addition to the ESG ratings process, using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments. Employing sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Sustainable Investing Exclusions" for additional information.

Risk [Heading]

Principal Investment Risks

Risk Narrative [Text Block]

Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments. Sustainability Risk. Application of FMR's ESG ratings process and/or its sustainable investing exclusion criteria may affect the fund's exposure to certain issuers, sectors, regions, and countries and may affect the fund's performance depending on whether certain investments are in or out of favor. The criteria related to the fund's ESG ratings process and/or adherence to its sustainable investing exclusion criteria may result in the fund forgoing opportunities to buy certain securities when it might otherwise be advantageous to do so, or selling securities for ESG reasons when it might be otherwise disadvantageous for it to do so. As a result, the fund's performance may at times be better or worse than the performance of funds that do not use ESG or sustainability criteria. There are significant differences in interpretations of what it means for an issuer to have positive ESG factors. While the Adviser believes its definitions are reasonable, the portfolio decisions it makes may differ with other investors' or advisers' views. When evaluating an issuer, the Adviser is dependent on information or data obtained through voluntary or third-party reporting that may be incomplete, inaccurate, or unavailable, which could cause the Adviser to incorrectly assess an issuer's business practices. Foreign Exposure. Foreign markets, particularly emerging markets, can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. The extent of economic development; political stability; market depth, infrastructure, and capitalization; and regulatory oversight can be less than in more developed markets. Emerging markets typically have less established legal, accounting and financial reporting systems than those in more developed markets, which may reduce the scope or quality of financial information available to investors. Emerging markets can be subject to greater social, economic, regulatory, and political uncertainties and can be extremely volatile. Foreign exchange rates also can be extremely volatile. Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. Management Risk The Adviser's application of the fund's strategy criteria may not achieve its intended results. The fund could underperform in comparison to other funds with a similar benchmark or similar objectives and investment strategies . An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency . You could lose money by investing in the fund.

Bar Chart and Performance Table [Heading]

Performance

Performance Narrative [Text Block]

Performance history will be available for the fund after the fund has been in operation for one calendar year.