v3.26.3
Label Element Value
SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk/Return [Heading] oef_RiskReturnHeading EMERGING MARKETS EQUITY FUND
Objective [Heading] oef_ObjectiveHeading Investment Goal
Objective, Primary [Text Block] oef_ObjectivePrimaryTextBlock

Capital appreciation.

Expense Heading [Optional Text] oef_ExpenseHeading Fees and Expenses
Expense Narrative [Text Block] oef_ExpenseNarrativeTextBlock

This table describes the fees and expenses that you may pay if you buy, hold, and sell Fund shares. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in this table and examples below.

Operating Expenses Caption [Optional Text] oef_OperatingExpensesCaption ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Expense Example [Heading] oef_ExpenseExampleHeading EXAMPLE
Expense Example Narrative [Text Block] oef_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 and then redeem or hold all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same.

Expense Example by, Year, Caption [Text] oef_ExpenseExampleByYearCaption Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Portfolio Turnover [Heading] oef_PortfolioTurnoverHeading PORTFOLIO TURNOVER
Portfolio Turnover [Text Block] oef_PortfolioTurnoverTextBlock

The Fund will pay 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 87% of the average value of its portfolio.

Portfolio Turnover, Rate oef_PortfolioTurnoverRate 87.00%
Strategy [Heading] oef_StrategyHeading Principal Investment Strategies
Strategy Narrative [Text Block] oef_StrategyNarrativeTextBlock

Under normal circumstances, the Emerging Markets Equity Fund will invest at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of emerging market issuers. Equity securities may include common stocks, preferred stocks, warrants, participation notes, depositary receipts and real estate investment trusts (REITs). The Fund normally maintains investments in at least six emerging market countries, however, it may invest a substantial amount of its assets in issuers located in a

single country or a limited number of countries. Due to the size of its economy relative to other emerging market countries, it is expected that China will generally constitute a significant exposure in the Fund and may include investments in variable interest entities (VIEs). Emerging market countries are those countries that are: (i) characterized as developing or emerging by any of the World Bank, the United Nations, the International Finance Corporation, or the European Bank for Reconstruction and Development; (ii) included in an emerging markets index by a recognized index provider; or (iii) countries with similar developing frontier or emerging characteristics as countries classified as emerging market countries pursuant to sub-paragraph (i) and (ii) above, in each case determined at the time of purchase.

The Fund uses a multi-manager approach, relying upon a number of sub-advisers (each, a Sub-Adviser and collectively, the Sub-Advisers) with differing investment philosophies to manage portions of the Fund’s portfolio under the general supervision of SEI Investments Management Corporation (SIMC or the Adviser).

The Fund may invest in swaps based on a single security or an index of securities, futures contracts, forward contracts on currencies, indexes or securities, and options on securities to synthetically obtain exposure to securities or baskets of securities or for hedging purposes, including seeking to manage the Fund’s currency exposure to foreign securities and mitigate the Fund’s overall risk. Securities index swaps may be used to obtain exposure to different foreign equity markets. Futures and swaps on futures may be used to gain exposure to foreign equity markets and commodities markets. The Fund may sell credit default swaps to more efficiently gain credit exposure to a security or basket of securities.

The Fund may purchase shares of exchange-traded funds (ETFs) and other investment companies to gain exposure to a particular portion of the market while awaiting an opportunity to purchase securities or other instruments directly. The Fund may also invest a portion of its assets in U.S. and developed foreign country securities, including securities of small capitalization companies.

Summary of Definition of Rule 35d-1 Term in Fund Name [Text Block] fnd_NmRule35d1TermDfnSmryTextBlock Equity securities may include common stocks, preferred stocks, warrants, participation notes, depositary receipts and real estate investment trusts (REITs). The Fund normally maintains investments in at least six emerging market countries, however, it may invest a substantial amount of its assets in issuers located in a single country or a limited number of countries. Due to the size of its economy relative to other emerging market countries, it is expected that China will generally constitute a significant exposure in the Fund and may include investments in variable interest entities (VIEs). Emerging market countries are those countries that are: (i) characterized as developing or emerging by any of the World Bank, the United Nations, the International Finance Corporation, or the European Bank for Reconstruction and Development; (ii) included in an emerging markets index by a recognized index provider; or (iii) countries with similar developing frontier or emerging characteristics as countries classified as emerging market countries pursuant to sub-paragraph (i) and (ii) above, in each case determined at the time of purchase.
Summary of Selection Criteria for Rule 35d-1 Term in Fund Name [Text Block] fnd_NmRule35d1TermSlctnCritSmryTextBlock The Fund uses a multi-manager approach, relying upon a number of sub-advisers (each, a Sub-Adviser and collectively, the Sub-Advisers) with differing investment philosophies to manage portions of the Fund’s portfolio under the general supervision of SEI Investments Management Corporation (SIMC or the Adviser).
Rule 35d-1 Eighty Percent Investment Policy [Text Block] fnd_NmRule35d1EightyPctInvstmntPlcyTextBlock Under normal circumstances, the Emerging Markets Equity Fund will invest at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of emerging market issuers.
Bar Chart and Performance Table [Heading] oef_BarChartAndPerformanceTableHeading Performance Information
Performance Narrative [Text Block] oef_PerformanceNarrativeTextBlock

The bar chart and the performance table below provide some indication of the risk of investing in the Fund by showing changes in the Fund’s performance from year to year for the past ten calendar years, and by showing how the Fund’s average annual returns for 1, 5 and 10 years and since the Fund’s inception, compare with those of a broad measure of market performance. The performance information shown is based on full calendar years. The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. For current performance information, please call 1‑800-DIAL-SEI.

Performance Information Illustrates Variability of Returns [Text] oef_PerformanceInformationIllustratesVariabilityOfReturns The bar chart and the performance table below provide some indication of the risk of investing in the Fund by showing changes in the Fund’s performance from year to year for the past ten calendar years, and by showing how the Fund’s average annual returns for 1, 5 and 10 years and since the Fund’s inception, compare with those of a broad measure of market performance.
Performance Additional Market Index [Text] oef_PerformanceAdditionalMarketIndex This table compares the Fund’s average annual total returns to those of a broad-based securities market index and an additional index with characteristics relevant to the Fund’s investment strategy.
Performance Availability Phone [Text] oef_PerformanceAvailabilityPhone 1‑800-DIAL-SEI
Performance Past Does Not Indicate Future [Text] oef_PerformancePastDoesNotIndicateFuture The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.
Bar Chart Closing [Text Block] oef_BarChartClosingTextBlock
Best Quarter: 21.74% (6/30/20)
Worst Quarter: -25.81% (3/31/20)
The Fund's total return from January 1, 2026 to June 30, 2026 was 22.28%.
Year to Date Return, Label [Optional Text] oef_YearToDateReturnLabel total return
Bar Chart, Year to Date Return, Date oef_BarChartYearToDateReturnDate Jun. 30, 2026
Bar Chart, Year to Date Return oef_BarChartYearToDateReturn 22.28%
Highest Quarterly Return, Label [Optional Text] oef_HighestQuarterlyReturnLabel Best Quarter:
Highest Quarterly Return, Date oef_BarChartHighestQuarterlyReturnDate Jun. 30, 2020
Highest Quarterly Return oef_BarChartHighestQuarterlyReturn 21.74%
Lowest Quarterly Return, Label [Optional Text] oef_LowestQuarterlyReturnLabel Worst Quarter:
Lowest Quarterly Return, Date oef_BarChartLowestQuarterlyReturnDate Mar. 31, 2020
Lowest Quarterly Return oef_BarChartLowestQuarterlyReturn (25.81%)
Performance Table Heading oef_PerformanceTableHeading Average Annual Total Returns (for the periods ended December 31, 2025)
Index No Deduction for Fees, Expenses, or Taxes [Text] oef_IndexNoDeductionForFeesExpensesTaxes (reflects no deduction for fees, expenses or taxes)
Performance Table Uses Highest Federal Rate oef_PerformanceTableUsesHighestFederalRate After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred oef_PerformanceTableNotRelevantToTaxDeferred Your actual after-tax returns will depend on your tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table Narrative oef_PerformanceTableNarrativeTextBlock

This table compares the Fund’s average annual total returns to those of a broad-based securities market index and an additional index with characteristics relevant to the Fund’s investment strategy.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Your actual after-tax returns will depend on your tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Risk Lose Money [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock You could lose money on your investment in the Fund, just as you could with other investments.
SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Risk Not Insured [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock 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.
SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Market Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Market Risk — The risk that the market value of a security may move up and down, sometimes rapidly and unpredictably. Market risk may affect a single issuer, an industry, a sector or the equity or bond market as a whole. Equity markets may decline significantly in response to adverse issuer, political, regulatory, market, economic or other developments that may cause broad changes in market value, public perceptions concerning these developments, and adverse investor sentiment or publicity. Similarly, environmental and public health risks, such as natural disasters, epidemics, pandemics or widespread fear that such events may occur, may impact markets adversely and cause market volatility in both the short- and long-term.

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Foreign Investment/Emerging and Frontier Markets Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Foreign Investment/Emerging and Frontier Markets Risk — The risk that non-U.S. securities may be subject to additional price volatility, illiquidity and decreases in value due to, among other things, political, social and economic developments abroad, government ownership or control of portions of the private sector or certain companies, trade barriers and currency movements, exchange controls and managed adjustments in relative currency values, and different or new and unsettled securities and tax markets, laws and regulations. These additional risks may be heightened with respect to emerging market countries because political turmoil and rapid changes in economic conditions are more likely to occur in these countries. These risks may be magnified further with respect to “frontier market countries,” which are a subset of emerging market countries with even smaller national economies. Investments in emerging markets are subject to the added risk that information in emerging market investments may be unreliable or outdated due to differences in regulatory, accounting or auditing and financial record keeping standards, or because less information about

emerging market investments is publicly available. In addition, the rights and remedies associated with emerging market investments may be different than investments in developed markets. A lack of reliable information, rights and remedies increase the risks of investing in emerging markets in comparison to more developed markets.

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Country Concentration Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Country Concentration Risk — The Fund’s concentration of its assets in issuers located in a single country or a limited number of countries will increase the impact of, and potential losses associated with, the risks set forth in the Foreign Investment/Emerging and Frontier Markets Risk.

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Risk of Investing in China [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Risk of Investing in China — Because China is an emerging market that may be subject to considerable government intervention and varying degrees of economic, political and social instability, such investments may be subject to greater risk of stock market, interest rate, and currency fluctuations, as well as inflation.

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Investment Style Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

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

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Large Capitalization Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

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

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Small and Medium Capitalization Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Small and Medium Capitalization Risk — The risk that small and medium capitalization companies in which the Fund may invest may be more vulnerable to adverse business or economic events than larger, more established companies. In particular, small and medium capitalization companies may have limited product lines, markets and financial resources, and may depend upon a relatively small management group. Therefore, small capitalization and medium capitalization stocks may be more volatile than those of larger companies. Small capitalization and medium capitalization stocks may be traded over-the-counter (OTC). OTC stocks may trade less frequently and in smaller volume than exchange listed stocks and may have more price volatility than that of exchange-listed stocks.

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Currency Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Currency Risk — As a result of the Fund’s investments in securities denominated in, and/or receiving revenues in, foreign currencies, the Fund will be subject to currency risk. Currency risk is the risk that foreign currencies will decline in value relative to the U.S. dollar or, in the case of hedging positions, that the U.S. dollar will decline in value relative to the currency hedged. In either event, the dollar value of an investment in the Fund would be adversely affected. Currency exchange rates may fluctuate in response to, among other things, changes in interest rates, intervention (or failure to intervene) by U.S. or foreign governments, central banks or supranational entities, or by the imposition of currency controls or other political developments in the United States or abroad.

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Preferred Stock Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Preferred Stock Risk — Preferred stock represents an equity or ownership interest in an issuer that pays dividends at a specified rate and that has precedence over common stock in the payment of dividends. In the event an issuer is liquidated or declares bankruptcy, the claims of owners of bonds take precedence over the claims of those who own preferred and common stock.

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Depositary Receipts Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Depositary Receipts Risk — Depositary receipts, such as American Depositary Receipts, are certificates evidencing ownership of shares of a foreign issuer that are issued by depositary banks and generally trade on an established market. Depositary receipts are subject to many of the risks associated with investing directly in foreign securities, including, among other things, political, social and economic developments abroad, currency movements and different legal, regulatory, tax, accounting and audit environments.

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Warrants Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Warrants Risk — Warrants are instruments that entitle the holder to buy an equity security at a specific price for a specific period of time. Warrants may be more speculative than other types of investments. The price of a warrant may be more volatile than the price of its underlying security, and a warrant may offer greater potential for capital appreciation as well as capital loss. A warrant ceases to have value if it is not exercised prior to its expiration date.

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Participation Notes (P-Notes) Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Participation Notes (P-Notes) Risk — P-Notes are participation interest notes that are issued by banks or broker-dealers and are designed to offer a return linked to a particular underlying equity, debt, currency or market. Investments in P-Notes involve the same risks associated with a direct investment in the underlying foreign companies or foreign securities markets that they seek to replicate. However, there can be no assurance that the trading price of P-Notes will equal the underlying value of the foreign companies or foreign securities markets that they seek to replicate.

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Derivatives Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

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

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Commodity-Linked Securities Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Commodity-Linked Securities Risk — Investments in commodity-linked securities may be more volatile and less liquid than direct investments in the underlying commodities themselves. Commodity-related equity returns can also be affected by the issuer’s financial structure or the performance of unrelated businesses.

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Investment Company Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Investment Company Risk — When the Fund invests in an investment company, including closed-end funds and ETFs, in addition to directly bearing the expenses associated with its own operations, it will bear a pro rata portion of the investment company’s expenses. Further, while the risks of owning shares of an investment company generally reflect the risks of owning the underlying investments of the investment company, the Fund may be subject to additional or different risks than if the Fund had invested directly in the underlying investments. For example, the lack of liquidity in an ETF could result in its value being more volatile than that of the underlying portfolio securities. Closed-end investment companies issue a fixed number of shares that trade on a stock exchange or over-the-counter at a premium or a discount to their net asset value. As a result, a closed-end fund’s share price fluctuates based on what another investor is willing to pay rather than on the market value of the securities in the fund.

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | REITs Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

REITs Risk — REITs are trusts that invest primarily in commercial real estate or real estate-related loans. The Fund’s investments in REITs will be subject to the risks associated with the direct ownership of real estate. Risks commonly associated with the direct ownership of real estate include fluctuations in the value of underlying properties, defaults by borrowers or tenants, changes in interest rates and risks related to general or local economic conditions. Some REITs may have limited diversification and may be subject to risks inherent in financing a limited number of properties.

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Liquidity Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

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

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Leverage Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Leverage Risk — The Fund’s use of derivatives may result in the Fund’s total investment exposure substantially exceeding the value of its portfolio securities and the Fund’s investment returns depending substantially on the performance of securities that the Fund may not directly own. The use of leverage can amplify the effects of market volatility on the Fund’s share price and may also cause the Fund to liquidate portfolio positions when it would not be advantageous to do so in order to satisfy its obligations. The Fund’s use of leverage may result in a heightened risk of investment loss.

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Credit Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

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

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | Opportunity Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Opportunity Risk — The risk of missing out on an investment opportunity because the assets necessary to take advantage of it are tied up in other investments.

SIIT EMERGING MARKETS EQUITY FUND | EMERGING MARKETS EQUITY FUND | SIIT EMERGING MARKETS EQUITY FUND - CLASS A  
Prospectus [Line Items] oef_ProspectusLineItems  
Management Fees (as a percentage of Assets) oef_ManagementFeesOverAssets 0.85%
Distribution and Service (12b-1) Fees oef_DistributionAndService12b1FeesOverAssets 0.00%
Other Expenses (as a percentage of Assets): oef_OtherExpensesOverAssets 0.17%
Expenses (as a percentage of Assets) oef_ExpensesOverAssets 1.02%
Expense Example, with Redemption, 1 Year oef_ExpenseExampleYear01 $ 104
Expense Example, with Redemption, 3 Years oef_ExpenseExampleYear03 325
Expense Example, with Redemption, 5 Years oef_ExpenseExampleYear05 563
Expense Example, with Redemption, 10 Years oef_ExpenseExampleYear10 $ 1,248
EMERGING MARKETS EQUITY FUND | MSCI All Country World Ex-US Net Index Return (reflects no deduction for fees or expenses)  
Prospectus [Line Items] oef_ProspectusLineItems  
Average Annual Return, Label [Optional Text] oef_AverageAnnualReturnLabel MSCI All Country World Ex-US Net Index Return (reflects no deduction for fees or expenses)
Average Annual Return, Percent oef_AvgAnnlRtrPct 32.39%
Average Annual Return, Percent oef_AvgAnnlRtrPct 7.91%
Average Annual Return, Percent oef_AvgAnnlRtrPct 8.41%
Average Annual Return, Percent oef_AvgAnnlRtrPct 6.66%
EMERGING MARKETS EQUITY FUND | MSCI Emerging & Frontier Markets Index Return (reflects no deduction for fees, expenses or taxes)  
Prospectus [Line Items] oef_ProspectusLineItems  
Average Annual Return, Label [Optional Text] oef_AverageAnnualReturnLabel MSCI Emerging & Frontier Markets Index Return (reflects no deduction for fees, expenses or taxes)
Average Annual Return, Percent oef_AvgAnnlRtrPct 33.78%
Average Annual Return, Percent oef_AvgAnnlRtrPct 4.26%
Average Annual Return, Percent oef_AvgAnnlRtrPct 8.39%
Average Annual Return, Percent oef_AvgAnnlRtrPct 5.38%
EMERGING MARKETS EQUITY FUND | SIIT EMERGING MARKETS EQUITY FUND - CLASS A  
Prospectus [Line Items] oef_ProspectusLineItems  
Annual Return [Percent] oef_AnnlRtrPct 10.26%
Annual Return [Percent] oef_AnnlRtrPct 33.51%
Annual Return [Percent] oef_AnnlRtrPct (17.59%)
Annual Return [Percent] oef_AnnlRtrPct 18.91%
Annual Return [Percent] oef_AnnlRtrPct 17.30%
Annual Return [Percent] oef_AnnlRtrPct 8.06%
Annual Return [Percent] oef_AnnlRtrPct (19.33%)
Annual Return [Percent] oef_AnnlRtrPct 16.63%
Annual Return [Percent] oef_AnnlRtrPct 9.25%
Annual Return [Percent] oef_AnnlRtrPct 39.81%
Average Annual Return, Label [Optional Text] oef_AverageAnnualReturnLabel Return Before Taxes
Average Annual Return, Percent oef_AvgAnnlRtrPct 39.81%
Average Annual Return, Percent oef_AvgAnnlRtrPct 9.20%
Average Annual Return, Percent oef_AvgAnnlRtrPct 10.14%
Average Annual Return, Percent oef_AvgAnnlRtrPct 7.29%
Performance Inception Date oef_PerfInceptionDate Oct. 31, 2014
EMERGING MARKETS EQUITY FUND | SIIT EMERGING MARKETS EQUITY FUND - CLASS A | After Taxes on Distributions  
Prospectus [Line Items] oef_ProspectusLineItems  
Average Annual Return, Label [Optional Text] oef_AverageAnnualReturnLabel Return After Taxes on Distributions
Average Annual Return, Percent oef_AvgAnnlRtrPct 31.12%
Average Annual Return, Percent oef_AvgAnnlRtrPct 6.40%
Average Annual Return, Percent oef_AvgAnnlRtrPct 8.20%
Average Annual Return, Percent oef_AvgAnnlRtrPct 5.55%
EMERGING MARKETS EQUITY FUND | SIIT EMERGING MARKETS EQUITY FUND - CLASS A | After Taxes on Distributions and Sales  
Prospectus [Line Items] oef_ProspectusLineItems  
Average Annual Return, Label [Optional Text] oef_AverageAnnualReturnLabel Return After Taxes on Distributions and Sale of Fund Shares
Average Annual Return, Percent oef_AvgAnnlRtrPct 28.57%
Average Annual Return, Percent oef_AvgAnnlRtrPct 6.89%
Average Annual Return, Percent oef_AvgAnnlRtrPct 7.93%
Average Annual Return, Percent oef_AvgAnnlRtrPct 5.54%