497

Exhibit Index

Exhibit No.
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 Extension Labels Linkbase
EX-101.PRE	XBRL Taxonomy Extension Presentation Linkbase

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Document Type	dei_DocumentType	497
Document Period End Date	dei_DocumentPeriodEndDate	Sep. 30, 2017
Registrant Name	dei_EntityRegistrantName	SELECT SECTOR SPDR TRUST
Central Index Key	dei_EntityCentralIndexKey	0001064641
Amendment Flag	dei_AmendmentFlag	false
Document Creation Date	dei_DocumentCreationDate	Sep. 24, 2018
Document Effective Date	dei_DocumentEffectiveDate	Sep. 24, 2018
Prospectus Date	rr_ProspectusDate	Sep. 24, 2018

XML

The Communication Services Select Sector SPDR Fund

<b>Fund Summaries<br/><br/>The Communication Services Select Sector SPDR Fund </b>

<b>Investment Objective </b>

The Communication Services Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Communication Services Select Sector Index (the “Index”).

<b>Fees and Expenses of the Fund </b>

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.

<b>Annual Fund Operating Expenses<br/><br/> (expenses that you pay each year as a percentage of the value of your investment): </b>

Annual Fund Operating Expenses	The Communication Services Select Sector SPDR Fund The Communication Services Select Sector SPDR Fund
Management fees	0.03%
Distribution and service (12b-1) fees	0.04%
Other expenses	0.08%	[1]
Total annual Fund operating expenses	0.15%
Less contractual fee waiver	(0.02%)	[2]
Net annual Fund operating expenses	0.13%

<b>Example: </b>

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 sell all of your Fund 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. The calculation of costs takes into account the effect of any current contractual fee waivers and/or reimbursements for the period in which the fee waiver and/or reimbursement is currently in place. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	Year 1	Year 3
The Communication Services Select Sector SPDR Fund | The Communication Services Select Sector SPDR Fund | USD ($)	14	43

<b>Portfolio Turnover: </b>

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. The Fund's portfolio turnover rate has been omitted because the Fund had not commenced investment operations as of the date of this Prospectus.

<b>The Fund's Principal Investment Strategy </b>

In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index.

Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. ("SSGA FM" or the "Adviser"), the investment adviser to the Fund).

The Index includes companies that have been identified as Communication Services companies by the Global Industry Classification Standard (GICS^®), including securities of companies from the following industries: diversified telecommunication services; wireless telecommunication services; media; entertainment; and interactive media & services. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC ("S&P DJI") based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research ("BofA Merrill Lynch") (S&P DJI and BofA Merrill Lynch, collectively, the "Index Provider") using a "modified market capitalization" methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the "Internal Revenue Code" or "IRC"). As of May 31, 2018, the Index was composed of 26 stocks.

The Index is sponsored by the Index Provider and compiled by S&P DJI (the "Index Compilation Agent"). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.

<b>Principal Risks of Investing in the Fund </b>

As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions.

Communication Services Sector Risk: The Fund's assets will be concentrated in the communication services sector, which means the Fund will be more affected by the performance of the communication services sector than a fund that is more diversified. Communication services companies are particularly vulnerable to the potential obsolescence of products and services due to technological advancement and the innovation of competitors. Companies in the communication services sector may also be affected by other competitive pressures, such as pricing competition, as well as research and development costs, substantial capital requirements and government regulation. Additionally, fluctuating domestic and international demand, shifting demographics and often unpredictable changes in consumer tastes can drastically affect a communication services company's profitability. While all companies may be susceptible to network security breaches, certain companies in the communication services sector may be particular targets of hacking and potential theft of proprietary or consumer information or disruptions in service, which could have a material adverse effect on their businesses.

Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time.

Non-Diversification Risk: As a "non-diversified" fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.

Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies.

Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.

<b>Fund Performance </b>

The Fund has not yet completed a full calendar year of investment operations and therefore does not have any performance history. Once the Fund has completed a full calendar year of operations, a bar chart and table will be included that will provide some indication of the risks of investing in the Fund by showing the variability of the Fund's returns based on net assets and comparing the Fund's performance to the Index. When available, updated performance information may be obtained by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.

[1] “Other expenses” are based on estimated amounts for the current fiscal year.

[2] SSGA Funds Management, Inc. (the “Adviser”) has contractually agreed to waive a portion of its advisory fee and reimburse certain expenses, until January 31, 2022, so that the annual Fund operating expenses of the Fund are limited to no more than 0.1345% of the Fund's average daily net assets (exclusive of non-recurring account fees and expenses). This contractual fee waiver and/or reimbursement does not provide for the recoupment by the Adviser of any amounts waived or reimbursed. The Adviser may continue such waiver and/or reimbursement from year to year, but there is no guarantee that the Adviser will do so after January 31, 2022. The waiver and/or reimbursement may not be terminated prior to January 31, 2022 except with the approval of The Select Sector SPDR Trust's Board of Trustees.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	SELECT SECTOR SPDR TRUST
Prospectus Date	rr_ProspectusDate	Sep. 24, 2018
The Communication Services Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<b>Fund Summaries<br/><br/>The Communication Services Select Sector SPDR Fund </b>
Objective [Heading]	rr_ObjectiveHeading	<b>Investment Objective </b>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Communication Services Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Communication Services Select Sector Index (the “Index”).
Expense [Heading]	rr_ExpenseHeading	<b>Fees and Expenses of the Fund </b>
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 (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<b>Annual Fund Operating Expenses<br/><br/> (expenses that you pay each year as a percentage of the value of your investment): </b>
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	January 31, 2022
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<b>Portfolio Turnover: </b>
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. The Fund's portfolio turnover rate has been omitted because the Fund had not commenced investment operations as of the date of this Prospectus.
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Other Expenses, New Fund, Based on Estimates [Text]	rr_OtherExpensesNewFundBasedOnEstimates	“Other expenses” are based on estimated amounts for the current fiscal year.
Expense Example [Heading]	rr_ExpenseExampleHeading	<b>Example: </b>
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, and then sell all of your Fund 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. The calculation of costs takes into account the effect of any current contractual fee waivers and/or reimbursements for the period in which the fee waiver and/or reimbursement is currently in place. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	<b>The Fund's Principal Investment Strategy </b>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index. Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. ("SSGA FM" or the "Adviser"), the investment adviser to the Fund). The Index includes companies that have been identified as Communication Services companies by the Global Industry Classification Standard (GICS®), including securities of companies from the following industries: diversified telecommunication services; wireless telecommunication services; media; entertainment; and interactive media & services. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC ("S&P DJI") based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research ("BofA Merrill Lynch") (S&P DJI and BofA Merrill Lynch, collectively, the "Index Provider") using a "modified market capitalization" methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the "Internal Revenue Code" or "IRC"). As of May 31, 2018, the Index was composed of 26 stocks. The Index is sponsored by the Index Provider and compiled by S&P DJI (the "Index Compilation Agent"). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.
Risk [Heading]	rr_RiskHeading	<b>Principal Risks of Investing in the Fund </b>
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions. Communication Services Sector Risk: The Fund's assets will be concentrated in the communication services sector, which means the Fund will be more affected by the performance of the communication services sector than a fund that is more diversified. Communication services companies are particularly vulnerable to the potential obsolescence of products and services due to technological advancement and the innovation of competitors. Companies in the communication services sector may also be affected by other competitive pressures, such as pricing competition, as well as research and development costs, substantial capital requirements and government regulation. Additionally, fluctuating domestic and international demand, shifting demographics and often unpredictable changes in consumer tastes can drastically affect a communication services company's profitability. While all companies may be susceptible to network security breaches, certain companies in the communication services sector may be particular targets of hacking and potential theft of proprietary or consumer information or disruptions in service, which could have a material adverse effect on their businesses. Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time. Non-Diversification Risk: As a "non-diversified" fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds. Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies. Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	<blockquote><b>Non-Diversification Risk:</b> As a "non-diversified" fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.</blockquote>
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<b>Fund Performance </b>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The Fund has not yet completed a full calendar year of investment operations and therefore does not have any performance history. Once the Fund has completed a full calendar year of operations, a bar chart and table will be included that will provide some indication of the risks of investing in the Fund by showing the variability of the Fund's returns based on net assets and comparing the Fund's performance to the Index. When available, updated performance information may be obtained by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	The Fund has not yet completed a full calendar year of investment operations and therefore does not have any performance history.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	1-866-732-8673
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.sectorspdrs.com
The Communication Services Select Sector SPDR Fund | The Communication Services Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Management fees	rr_ManagementFeesOverAssets	0.03%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.04%
Other expenses	rr_OtherExpensesOverAssets	0.08%	[1]
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.15%
Less contractual fee waiver	rr_FeeWaiverOrReimbursementOverAssets	(0.02%)	[2]
Net annual Fund operating expenses	rr_NetExpensesOverAssets	0.13%
Year 1	rr_ExpenseExampleYear01	$ 14
Year 3	rr_ExpenseExampleYear03	$ 43

[1] “Other expenses” are based on estimated amounts for the current fiscal year.

[2] SSGA Funds Management, Inc. (the “Adviser”) has contractually agreed to waive a portion of its advisory fee and reimburse certain expenses, until January 31, 2022, so that the annual Fund operating expenses of the Fund are limited to no more than 0.1345% of the Fund's average daily net assets (exclusive of non-recurring account fees and expenses). This contractual fee waiver and/or reimbursement does not provide for the recoupment by the Adviser of any amounts waived or reimbursed. The Adviser may continue such waiver and/or reimbursement from year to year, but there is no guarantee that the Adviser will do so after January 31, 2022. The waiver and/or reimbursement may not be terminated prior to January 31, 2022 except with the approval of The Select Sector SPDR Trust's Board of Trustees.

XML

The Consumer Discretionary Select Sector SPDR Fund

<b>Fund Summaries <br/><br/>The Consumer Discretionary Select Sector SPDR Fund</b>

<b>Investment Objective </b>

The Consumer Discretionary Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Consumer Discretionary Select Sector Index (the “Index”).

<b>Fees and Expenses of the Fund </b>

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.

<b>Annual Fund Operating Expenses <br/><br/> (expenses that you pay each year as a percentage of the value of your investment): </b>

Annual Fund Operating Expenses	The Consumer Discretionary Select Sector SPDR Fund The Consumer Discretionary Select Sector SPDR Fund
Management fees	0.03%
Distribution and service (12b-1) fees	0.04%
Other expenses	0.06%
Total annual Fund operating expenses	0.13%	[1]

<b>Example: </b>

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 sell all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	Year 1	Year 3	Year 5	Year 10
The Consumer Discretionary Select Sector SPDR Fund | The Consumer Discretionary Select Sector SPDR Fund | USD ($)	13	42	73	166

<b>Portfolio Turnover: </b>

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 6% of the average value of its portfolio.

<b>The Fund's Principal Investment Strategy </b>

In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index.

Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund).

The Index includes companies that have been identified as Consumer Discretionary companies by the Global Industry Classification Standard (GICS^®), including securities of companies from the following industries: retail (specialty, multiline, internet and direct marketing); hotels, restaurants and leisure; textiles, apparel and luxury goods; household durables; automobiles; auto components; distributors; leisure products; and diversified consumer services. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC (“S&P DJI”) based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research (“BofA Merrill Lynch”) (S&P DJI and BofA Merrill Lynch, collectively, the “Index Provider”) using a “modified market capitalization” methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code” or “IRC”). As of November 30, 2017, the Index was composed of 84 stocks.

The Index is sponsored by the Index Provider and compiled by S&P DJI (the “Index Compilation Agent”). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.

<b>Principal Risks of Investing in the Fund </b>

As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions.

Consumer Discretionary Sector Risk: The Fund's assets will be concentrated in the consumer discretionary sector, which means the Fund will be more affected by the performance of the consumer discretionary sector than a fund that is more diversified. The success of consumer product manufacturers and retailers is tied closely to the performance of the overall domestic and global economy, interest rates, competition and consumer confidence. Success depends heavily on disposable household income and consumer spending. Also, companies in the consumer discretionary sector may be subject to severe competition, which may have an adverse impact on their respective profitability. Changes in demographics and consumer tastes can also affect the demand for, and success of, consumer products and services in the marketplace.

Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time.

Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.

Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies.

Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.

<b>Fund Performance </b>

The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.

<b>Annual Total Returns (years ended 12/31) </b>

Highest Quarterly Return: 19.24% (Q3, 2009)
Lowest Quarterly Return: -22.81% (Q4, 2008)

<b>Average Annual Total Returns (for periods ending 12/31/17) </b>

The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.

Average Annual Total Returns - The Consumer Discretionary Select Sector SPDR Fund	One Year	Five Years	Ten Years
The Consumer Discretionary Select Sector SPDR Fund	22.77%	17.43%	13.35%
The Consumer Discretionary Select Sector SPDR Fund | Return After Taxes on Distributions	22.39%	17.02%	13.00%
The Consumer Discretionary Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares	13.16%	14.06%	11.13%
The Consumer Discretionary Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)	22.98%	17.64%	13.53%
S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)	21.83%	15.79%	8.50%

[1] The Fund's "Total annual Fund operating expenses" have been restated to reflect a reduction in the Fund's "Distribution and service (12b-1) fees" and "Other expenses".

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	SELECT SECTOR SPDR TRUST
Prospectus Date	rr_ProspectusDate	Sep. 24, 2018
The Consumer Discretionary Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<b>Fund Summaries <br/><br/>The Consumer Discretionary Select Sector SPDR Fund</b>
Objective [Heading]	rr_ObjectiveHeading	<b>Investment Objective </b>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Consumer Discretionary Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Consumer Discretionary Select Sector Index (the “Index”).
Expense [Heading]	rr_ExpenseHeading	<b>Fees and Expenses of the Fund </b>
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 (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<b>Annual Fund Operating Expenses <br/><br/> (expenses that you pay each year as a percentage of the value of your investment): </b>
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<b>Portfolio Turnover: </b>
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 6% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	6.00%
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Expenses Restated to Reflect Current [Text]	rr_ExpensesRestatedToReflectCurrent	The Fund's "Total annual Fund operating expenses" have been restated to reflect a reduction in the Fund's "Distribution and service (12b-1) fees" and "Other expenses".
Expense Example [Heading]	rr_ExpenseExampleHeading	<b>Example: </b>
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, and then sell all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	<b>The Fund's Principal Investment Strategy </b>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index. Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund). The Index includes companies that have been identified as Consumer Discretionary companies by the Global Industry Classification Standard (GICS®), including securities of companies from the following industries: retail (specialty, multiline, internet and direct marketing); hotels, restaurants and leisure; textiles, apparel and luxury goods; household durables; automobiles; auto components; distributors; leisure products; and diversified consumer services. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC (“S&P DJI”) based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research (“BofA Merrill Lynch”) (S&P DJI and BofA Merrill Lynch, collectively, the “Index Provider”) using a “modified market capitalization” methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code” or “IRC”). As of November 30, 2017, the Index was composed of 84 stocks. The Index is sponsored by the Index Provider and compiled by S&P DJI (the “Index Compilation Agent”). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.
Risk [Heading]	rr_RiskHeading	<b>Principal Risks of Investing in the Fund </b>
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions. Consumer Discretionary Sector Risk: The Fund's assets will be concentrated in the consumer discretionary sector, which means the Fund will be more affected by the performance of the consumer discretionary sector than a fund that is more diversified. The success of consumer product manufacturers and retailers is tied closely to the performance of the overall domestic and global economy, interest rates, competition and consumer confidence. Success depends heavily on disposable household income and consumer spending. Also, companies in the consumer discretionary sector may be subject to severe competition, which may have an adverse impact on their respective profitability. Changes in demographics and consumer tastes can also affect the demand for, and success of, consumer products and services in the marketplace. Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time. Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds. Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies. Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	<blockquote><b>Non-Diversification Risk:</b> As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.</blockquote>
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<b>Fund Performance </b>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	1-866-732-8673
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.sectorspdrs.com
Performance Past Does Not Indicate Future [Text]	rr_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 [Heading]	rr_BarChartHeading	<b>Annual Total Returns (years ended 12/31) </b>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Highest Quarterly Return: 19.24% (Q3, 2009) Lowest Quarterly Return: -22.81% (Q4, 2008)
Performance Table Heading	rr_PerformanceTableHeading	<b>Average Annual Total Returns (for periods ending 12/31/17) </b>
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	The after-tax returns presented in the table below are calculated using highest historical individual federal marginal income tax rates 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 will depend on your specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
The Consumer Discretionary Select Sector SPDR Fund | The Consumer Discretionary Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Management fees	rr_ManagementFeesOverAssets	0.03%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.04%
Other expenses	rr_OtherExpensesOverAssets	0.06%
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.13%	[1]
Year 1	rr_ExpenseExampleYear01	$ 13
Year 3	rr_ExpenseExampleYear03	42
Year 5	rr_ExpenseExampleYear05	73
Year 10	rr_ExpenseExampleYear10	$ 166
2008	rr_AnnualReturn2008	(33.43%)
2009	rr_AnnualReturn2009	41.16%
2010	rr_AnnualReturn2010	27.39%
2011	rr_AnnualReturn2011	5.95%
2012	rr_AnnualReturn2012	23.58%
2013	rr_AnnualReturn2013	42.72%
2014	rr_AnnualReturn2014	9.49%
2015	rr_AnnualReturn2015	9.94%
2016	rr_AnnualReturn2016	5.88%
2017	rr_AnnualReturn2017	22.77%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest Quarterly Return:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Sep. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	19.24%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest Quarterly Return:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(22.81%)
One Year	rr_AverageAnnualReturnYear01	22.77%
Five Years	rr_AverageAnnualReturnYear05	17.43%
Ten Years	rr_AverageAnnualReturnYear10	13.35%
The Consumer Discretionary Select Sector SPDR Fund | Return After Taxes on Distributions | The Consumer Discretionary Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	22.39%
Five Years	rr_AverageAnnualReturnYear05	17.02%
Ten Years	rr_AverageAnnualReturnYear10	13.00%
The Consumer Discretionary Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares | The Consumer Discretionary Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	13.16%
Five Years	rr_AverageAnnualReturnYear05	14.06%
Ten Years	rr_AverageAnnualReturnYear10	11.13%
The Consumer Discretionary Select Sector SPDR Fund | The Consumer Discretionary Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	22.98%
Five Years	rr_AverageAnnualReturnYear05	17.64%
Ten Years	rr_AverageAnnualReturnYear10	13.53%
The Consumer Discretionary Select Sector SPDR Fund | S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	21.83%
Five Years	rr_AverageAnnualReturnYear05	15.79%
Ten Years	rr_AverageAnnualReturnYear10	8.50%

[1] The Fund's "Total annual Fund operating expenses" have been restated to reflect a reduction in the Fund's "Distribution and service (12b-1) fees" and "Other expenses".

XML

The Consumer Staples Select Sector SPDR Fund

<b>Fund Summaries <br/><br/>The Consumer Staples Select Sector SPDR Fund</b>

<b>Investment Objective </b>

The Consumer Staples Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Consumer Staples Select Sector Index (the “Index”).

<b>Fees and Expenses of the Fund </b>

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.

<b>Annual Fund Operating Expenses <br/><br/> (expenses that you pay each year as a percentage of the value of your investment): </b>

Annual Fund Operating Expenses	The Consumer Staples Select Sector SPDR Fund The Consumer Staples Select Sector SPDR Fund
Management fees	0.03%
Distribution and service (12b-1) fees	0.04%
Other expenses	0.06%
Total annual Fund operating expenses	0.13%	[1]

<b>Example: </b>

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 sell all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	Year 1	Year 3	Year 5	Year 10
The Consumer Staples Select Sector SPDR Fund | The Consumer Staples Select Sector SPDR Fund | USD ($)	13	42	73	166

<b>Portfolio Turnover: </b>

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 12% of the average value of its portfolio.

<b>The Fund's Principal Investment Strategy </b>

In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index.

Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. ("SSGA FM" or the "Adviser"), the investment adviser to the Fund).

The Index includes companies that have been identified as Consumer Staples companies by the Global Industry Classification Standard (GICS^®), including securities of companies from the following industries: food and staples retailing; household products; food products; beverages; tobacco; and personal products. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC ("S&P DJI") based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research ("BofA Merrill Lynch") (S&P DJI and BofA Merrill Lynch, collectively, the "Index Provider") using a "modified market capitalization" methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the "Internal Revenue Code" or "IRC"). As of November 30, 2017, the Index was composed of 34 stocks.

The Index is sponsored by the Index Provider and compiled by S&P DJI (the "Index Compilation Agent"). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.

<b>Principal Risks of Investing in the Fund </b>

As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions.

Consumer Staples Sector Risk: The Fund's assets will be concentrated in the consumer staples sector, which means the Fund will be more affected by the performance of the consumer staples sector than a fund that is more diversified. Consumer staples companies are subject to government regulation affecting their products which may negatively impact such companies' performance. For instance, government regulations may affect the permissibility of using various food additives and production methods of companies that make food products, which could affect company profitability. Tobacco companies may be adversely affected by the adoption of proposed legislation and/or by litigation. Also, the success of food, beverage, household and personal product companies may be strongly affected by consumer interest, marketing campaigns and other factors affecting supply and demand, including performance of the overall domestic and global economy, interest rates, competition and consumer confidence and spending.

Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time.

Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.

Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies.

Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.

<b>Fund Performance </b>

The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.

<b>Annual Total Returns (years ended 12/31) </b>

Highest Quarterly Return: 14.59% (Q1, 2013)
Lowest Quarterly Return: -12.29% (Q4, 2008)

<b>Average Annual Total Returns (for periods ending 12/31/17)</b>

The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.

Average Annual Total Returns - The Consumer Staples Select Sector SPDR Fund	One Year	Five Years	Ten Years
The Consumer Staples Select Sector SPDR Fund	12.92%	13.13%	9.97%
The Consumer Staples Select Sector SPDR Fund | Return After Taxes on Distributions	12.13%	12.39%	9.36%
The Consumer Staples Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares	7.79%	10.36%	8.10%
The Consumer Staples Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)	13.09%	13.34%	10.18%
S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)	21.83%	15.79%	8.50%

[1] The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	SELECT SECTOR SPDR TRUST
Prospectus Date	rr_ProspectusDate	Sep. 24, 2018
The Consumer Staples Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<b>Fund Summaries <br/><br/>The Consumer Staples Select Sector SPDR Fund</b>
Objective [Heading]	rr_ObjectiveHeading	<b>Investment Objective </b>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Consumer Staples Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Consumer Staples Select Sector Index (the “Index”).
Expense [Heading]	rr_ExpenseHeading	<b>Fees and Expenses of the Fund </b>
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 (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<b>Annual Fund Operating Expenses <br/><br/> (expenses that you pay each year as a percentage of the value of your investment): </b>
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<b>Portfolio Turnover: </b>
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 12% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	12.00%
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Expenses Restated to Reflect Current [Text]	rr_ExpensesRestatedToReflectCurrent	The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.
Expense Example [Heading]	rr_ExpenseExampleHeading	<b>Example: </b>
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, and then sell all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	<b>The Fund's Principal Investment Strategy </b>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index. Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. ("SSGA FM" or the "Adviser"), the investment adviser to the Fund). The Index includes companies that have been identified as Consumer Staples companies by the Global Industry Classification Standard (GICS®), including securities of companies from the following industries: food and staples retailing; household products; food products; beverages; tobacco; and personal products. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC ("S&P DJI") based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research ("BofA Merrill Lynch") (S&P DJI and BofA Merrill Lynch, collectively, the "Index Provider") using a "modified market capitalization" methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the "Internal Revenue Code" or "IRC"). As of November 30, 2017, the Index was composed of 34 stocks. The Index is sponsored by the Index Provider and compiled by S&P DJI (the "Index Compilation Agent"). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.
Risk [Heading]	rr_RiskHeading	<b>Principal Risks of Investing in the Fund </b>
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions. Consumer Staples Sector Risk: The Fund's assets will be concentrated in the consumer staples sector, which means the Fund will be more affected by the performance of the consumer staples sector than a fund that is more diversified. Consumer staples companies are subject to government regulation affecting their products which may negatively impact such companies' performance. For instance, government regulations may affect the permissibility of using various food additives and production methods of companies that make food products, which could affect company profitability. Tobacco companies may be adversely affected by the adoption of proposed legislation and/or by litigation. Also, the success of food, beverage, household and personal product companies may be strongly affected by consumer interest, marketing campaigns and other factors affecting supply and demand, including performance of the overall domestic and global economy, interest rates, competition and consumer confidence and spending. Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time. Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds. Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies. Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	<blockquote><b>Non-Diversification Risk:</b> As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.</blockquote>
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<b>Fund Performance </b>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	1-866-732-8673
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.sectorspdrs.com
Performance Past Does Not Indicate Future [Text]	rr_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 [Heading]	rr_BarChartHeading	<b>Annual Total Returns (years ended 12/31) </b>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Highest Quarterly Return: 14.59% (Q1, 2013) Lowest Quarterly Return: -12.29% (Q4, 2008)
Performance Table Heading	rr_PerformanceTableHeading	<b>Average Annual Total Returns (for periods ending 12/31/17)</b>
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	The after-tax returns presented in the table below are calculated using highest historical individual federal marginal income tax rates 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 will depend on your specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
The Consumer Staples Select Sector SPDR Fund | The Consumer Staples Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Management fees	rr_ManagementFeesOverAssets	0.03%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.04%
Other expenses	rr_OtherExpensesOverAssets	0.06%
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.13%	[1]
Year 1	rr_ExpenseExampleYear01	$ 13
Year 3	rr_ExpenseExampleYear03	42
Year 5	rr_ExpenseExampleYear05	73
Year 10	rr_ExpenseExampleYear10	$ 166
2008	rr_AnnualReturn2008	(14.98%)
2009	rr_AnnualReturn2009	14.21%
2010	rr_AnnualReturn2010	13.86%
2011	rr_AnnualReturn2011	14.00%
2012	rr_AnnualReturn2012	10.72%
2013	rr_AnnualReturn2013	26.27%
2014	rr_AnnualReturn2014	15.86%
2015	rr_AnnualReturn2015	6.83%
2016	rr_AnnualReturn2016	5.00%
2017	rr_AnnualReturn2017	12.92%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest Quarterly Return:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Mar. 31, 2013
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	14.59%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest Quarterly Return:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(12.29%)
One Year	rr_AverageAnnualReturnYear01	12.92%
Five Years	rr_AverageAnnualReturnYear05	13.13%
Ten Years	rr_AverageAnnualReturnYear10	9.97%
The Consumer Staples Select Sector SPDR Fund | Return After Taxes on Distributions | The Consumer Staples Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	12.13%
Five Years	rr_AverageAnnualReturnYear05	12.39%
Ten Years	rr_AverageAnnualReturnYear10	9.36%
The Consumer Staples Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares | The Consumer Staples Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	7.79%
Five Years	rr_AverageAnnualReturnYear05	10.36%
Ten Years	rr_AverageAnnualReturnYear10	8.10%
The Consumer Staples Select Sector SPDR Fund | The Consumer Staples Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	13.09%
Five Years	rr_AverageAnnualReturnYear05	13.34%
Ten Years	rr_AverageAnnualReturnYear10	10.18%
The Consumer Staples Select Sector SPDR Fund | S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	21.83%
Five Years	rr_AverageAnnualReturnYear05	15.79%
Ten Years	rr_AverageAnnualReturnYear10	8.50%

[1] The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.

XML

The Energy Select Sector SPDR Fund

<b>Fund Summaries <br/><br/>The Energy Select Sector SPDR Fund</b>

<b>Investment Objective </b>

The Energy Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Energy Select Sector Index (the “Index”).

<b>Fees and Expenses of the Fund </b>

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.

<b>Annual Fund Operating Expenses <br/><br/> (expenses that you pay each year as a percentage of the value of your investment): </b>

Annual Fund Operating Expenses	The Energy Select Sector SPDR Fund The Energy Select Sector SPDR Fund
Management fees	0.03%
Distribution and service (12b-1) fees	0.04%
Other expenses	0.06%
Total annual Fund operating expenses	0.13%	[1]

<b>Example: </b>

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 sell all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	Year 1	Year 3	Year 5	Year 10
The Energy Select Sector SPDR Fund | The Energy Select Sector SPDR Fund | USD ($)	13	42	73	166

<b>Portfolio Turnover: </b>

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 23% of the average value of its portfolio.

<b>The Fund's Principal Investment Strategy </b>

In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index.

Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund).

The Index includes companies that have been identified as Energy companies by the Global Industry Classification Standard (GICS^®), including securities of companies from the following industries: oil, gas and consumable fuels; and energy equipment and services. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S& P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC (“S&P DJI”) based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research (“BofA Merrill Lynch”) (S&P DJI and BofA Merrill Lynch, collectively, the “Index Provider”) using a “modified market capitalization” methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code” or “IRC”). As of November 30, 2017, the Index was composed of 32 stocks.

The Index is sponsored by the Index Provider and compiled by S&P DJI (the “Index Compilation Agent”). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.

<b>Principal Risks of Investing in the Fund </b>

As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions.

Energy Sector Risk: The Fund's assets will be concentrated in the energy sector, which means the Fund will be more affected by the performance of the energy sector than a fund that is more diversified. Issuers in energy-related industries can be significantly affected by fluctuations in energy prices and supply and demand of energy fuels. Markets for various energy-related commodities can have significant volatility, and are subject to control or manipulation by large producers or purchasers. Companies in the energy sector may need to make substantial expenditures, and to incur significant amounts of debt, in order to maintain or expand their reserves. Oil and gas exploration and production can be significantly affected by natural disasters as well as changes in exchange rates, interest rates, government regulation, world events and economic conditions. These companies may be at risk for environmental damage claims.

Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time.

Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.

Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies.

Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.

<b>Fund Performance </b>

The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.

<b>Annual Total Returns (years ended 12/31) </b>

Highest Quarterly Return: 22.12% (Q4, 2010)
Lowest Quarterly Return: -27.52% (Q3, 2008)

<b>Average Annual Total Returns (for periods ending 12/31/17) </b>

The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.

Average Annual Total Returns - The Energy Select Sector SPDR Fund	One Year	Five Years	Ten Years
The Energy Select Sector SPDR Fund	(1.06%)	2.78%	1.19%
The Energy Select Sector SPDR Fund | Return After Taxes on Distributions	(1.81%)	2.15%	0.75%
The Energy Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares	(0.05%)	2.10%	0.93%
The Energy Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)	(0.86%)	2.91%	1.34%
S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)	21.83%	15.79%	8.50%

[1] The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	SELECT SECTOR SPDR TRUST
Prospectus Date	rr_ProspectusDate	Sep. 24, 2018
The Energy Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<b>Fund Summaries <br/><br/>The Energy Select Sector SPDR Fund</b>
Objective [Heading]	rr_ObjectiveHeading	<b>Investment Objective </b>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Energy Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Energy Select Sector Index (the “Index”).
Expense [Heading]	rr_ExpenseHeading	<b>Fees and Expenses of the Fund </b>
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 (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<b>Annual Fund Operating Expenses <br/><br/> (expenses that you pay each year as a percentage of the value of your investment): </b>
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<b>Portfolio Turnover: </b>
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 23% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	23.00%
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Expenses Restated to Reflect Current [Text]	rr_ExpensesRestatedToReflectCurrent	The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.
Expense Example [Heading]	rr_ExpenseExampleHeading	<b>Example: </b>
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, and then sell all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	<b>The Fund's Principal Investment Strategy </b>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index. Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund). The Index includes companies that have been identified as Energy companies by the Global Industry Classification Standard (GICS®), including securities of companies from the following industries: oil, gas and consumable fuels; and energy equipment and services. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S& P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC (“S&P DJI”) based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research (“BofA Merrill Lynch”) (S&P DJI and BofA Merrill Lynch, collectively, the “Index Provider”) using a “modified market capitalization” methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code” or “IRC”). As of November 30, 2017, the Index was composed of 32 stocks. The Index is sponsored by the Index Provider and compiled by S&P DJI (the “Index Compilation Agent”). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.
Risk [Heading]	rr_RiskHeading	<b>Principal Risks of Investing in the Fund </b>
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions. Energy Sector Risk: The Fund's assets will be concentrated in the energy sector, which means the Fund will be more affected by the performance of the energy sector than a fund that is more diversified. Issuers in energy-related industries can be significantly affected by fluctuations in energy prices and supply and demand of energy fuels. Markets for various energy-related commodities can have significant volatility, and are subject to control or manipulation by large producers or purchasers. Companies in the energy sector may need to make substantial expenditures, and to incur significant amounts of debt, in order to maintain or expand their reserves. Oil and gas exploration and production can be significantly affected by natural disasters as well as changes in exchange rates, interest rates, government regulation, world events and economic conditions. These companies may be at risk for environmental damage claims. Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time. Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds. Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies. Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	<blockquote><b>Non-Diversification Risk:</b> As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.</blockquote>
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<b>Fund Performance </b>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	1-866-732-8673
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.sectorspdrs.com
Performance Past Does Not Indicate Future [Text]	rr_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 [Heading]	rr_BarChartHeading	<b>Annual Total Returns (years ended 12/31) </b>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Highest Quarterly Return: 22.12% (Q4, 2010) Lowest Quarterly Return: -27.52% (Q3, 2008)
Performance Table Heading	rr_PerformanceTableHeading	<b>Average Annual Total Returns (for periods ending 12/31/17) </b>
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	The after-tax returns presented in the table below are calculated using highest historical individual federal marginal income tax rates 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 will depend on your specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
The Energy Select Sector SPDR Fund | The Energy Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Management fees	rr_ManagementFeesOverAssets	0.03%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.04%
Other expenses	rr_OtherExpensesOverAssets	0.06%
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.13%	[1]
Year 1	rr_ExpenseExampleYear01	$ 13
Year 3	rr_ExpenseExampleYear03	42
Year 5	rr_ExpenseExampleYear05	73
Year 10	rr_ExpenseExampleYear10	$ 166
2008	rr_AnnualReturn2008	(38.79%)
2009	rr_AnnualReturn2009	21.58%
2010	rr_AnnualReturn2010	21.72%
2011	rr_AnnualReturn2011	2.98%
2012	rr_AnnualReturn2012	5.21%
2013	rr_AnnualReturn2013	26.16%
2014	rr_AnnualReturn2014	(8.60%)
2015	rr_AnnualReturn2015	(21.46%)
2016	rr_AnnualReturn2016	28.01%
2017	rr_AnnualReturn2017	(1.06%)
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest Quarterly Return:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Dec. 31, 2010
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	22.12%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest Quarterly Return:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Sep. 30, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(27.52%)
One Year	rr_AverageAnnualReturnYear01	(1.06%)
Five Years	rr_AverageAnnualReturnYear05	2.78%
Ten Years	rr_AverageAnnualReturnYear10	1.19%
The Energy Select Sector SPDR Fund | Return After Taxes on Distributions | The Energy Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	(1.81%)
Five Years	rr_AverageAnnualReturnYear05	2.15%
Ten Years	rr_AverageAnnualReturnYear10	0.75%
The Energy Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares | The Energy Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	(0.05%)
Five Years	rr_AverageAnnualReturnYear05	2.10%
Ten Years	rr_AverageAnnualReturnYear10	0.93%
The Energy Select Sector SPDR Fund | The Energy Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	(0.86%)
Five Years	rr_AverageAnnualReturnYear05	2.91%
Ten Years	rr_AverageAnnualReturnYear10	1.34%
The Energy Select Sector SPDR Fund | S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	21.83%
Five Years	rr_AverageAnnualReturnYear05	15.79%
Ten Years	rr_AverageAnnualReturnYear10	8.50%

[1] The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.

XML

The Financial Select Sector SPDR Fund

<b>Fund Summaries </b><br/><br/><b>The Financial Select Sector SPDR Fund </b>

<b>Investment Objective </b>

The Financial Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Financial Select Sector Index (the “Index”).

<b>Fees and Expenses of the Fund </b>

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.

<b>Annual Fund Operating Expenses <br/><br/> (expenses that you pay each year as a percentage of the value of your investment):</b>

Annual Fund Operating Expenses	The Financial Select Sector SPDR Fund The Financial Select Sector SPDR Fund
Management fees	0.03%
Distribution and service (12b-1) fees	0.04%
Other expenses	0.06%
Total annual Fund operating expenses	0.13%	[1]

<b>Example: </b>

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 sell all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	Year 1	Year 3	Year 5	Year 10
The Financial Select Sector SPDR Fund | The Financial Select Sector SPDR Fund | USD ($)	13	42	73	166

<b>Portfolio Turnover: </b>

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 3% of the average value of its portfolio.

<b>The Fund's Principal Investment Strategy </b>

In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index.

Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund).

The Index includes companies that have been identified as Financial companies by the Global Industry Classification Standard (GICS^®), including securities of companies from the following industries: diversified financial services; insurance; banks; capital markets; mortgage real estate investment trusts (“REITs”); consumer finance; and thrifts and mortgage finance. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC (“S&P DJI”) based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research (“BofA Merrill Lynch”) (S&P DJI and BofA Merrill Lynch, collectively, the “Index Provider”) using a “modified market capitalization” methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code” or “IRC”). As of November 30, 2017, the Index was composed of 67 stocks.

The Index is sponsored by the Index Provider and compiled by S&P DJI (the “Index Compilation Agent”). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.

<b>Principal Risks of Investing in the Fund </b>

As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions.

Financial Sector Risk: The Fund's assets will be concentrated in the financial sector, which means the Fund will be more affected by the performance of the financial sector than a fund that is more diversified. Financial services companies are subject to extensive governmental regulation which may limit both the amounts and types of loans and other financial commitments they can make, the interest rates and fees they can charge, the scope of their activities, the prices they can charge and the amount of capital they must maintain. Profitability is largely dependent on the availability and cost of capital funds and can fluctuate significantly when interest rates change or due to increased competition. In addition, deterioration of the credit markets generally may cause an adverse impact in a broad range of markets, including U.S. and international credit and interbank money markets generally, thereby affecting a wide range of financial institutions and markets. Certain events in the financial sector may cause an unusually high degree of volatility in the financial markets, both domestic and foreign, and cause certain financial services companies to incur large losses. Securities of financial services companies may experience a dramatic decline in value when such companies experience substantial declines in the valuations of their assets, take action to raise capital (such as the issuance of debt or equity securities), or cease operations. Credit losses resulting from financial difficulties of borrowers and financial losses associated with investment activities can negatively impact the sector. Insurance companies may be subject to severe price competition. Adverse economic, business or political developments could adversely affect financial institutions engaged in mortgage finance or other lending or investing activities directly or indirectly connected to the value of real estate.

Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time.

Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.

Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies.

Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.

<b>Fund Performance </b>

The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.

<b>Annual Total Returns (years ended 12/31) </b>

Highest Quarterly Return: 35.82% (Q2, 2009)
Lowest Quarterly Return: -36.84% (Q4, 2008)

<b>Average Annual Total Returns (for periods ending 12/31/17) </b>

The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.

Average Annual Total Returns - The Financial Select Sector SPDR Fund	One Year	Five Years	Ten Years
The Financial Select Sector SPDR Fund	22.04%	18.07%	3.71%
The Financial Select Sector SPDR Fund | Return After Taxes on Distributions	21.52%	16.81%	2.93%
The Financial Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares	12.75%	14.60%	2.79%
The Financial Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)	22.18%	18.21%	3.79%
S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)	21.83%	15.79%	8.50%

[1] The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	SELECT SECTOR SPDR TRUST
Prospectus Date	rr_ProspectusDate	Sep. 24, 2018
The Financial Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<b>Fund Summaries </b><br/><br/><b>The Financial Select Sector SPDR Fund </b>
Objective [Heading]	rr_ObjectiveHeading	<b>Investment Objective </b>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Financial Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Financial Select Sector Index (the “Index”).
Expense [Heading]	rr_ExpenseHeading	<b>Fees and Expenses of the Fund </b>
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 (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<b>Annual Fund Operating Expenses <br/><br/> (expenses that you pay each year as a percentage of the value of your investment):</b>
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<b>Portfolio Turnover: </b>
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 3% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	3.00%
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Expenses Restated to Reflect Current [Text]	rr_ExpensesRestatedToReflectCurrent	The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.
Expense Example [Heading]	rr_ExpenseExampleHeading	<b>Example: </b>
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, and then sell all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	<b>The Fund's Principal Investment Strategy </b>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index. Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund). The Index includes companies that have been identified as Financial companies by the Global Industry Classification Standard (GICS®), including securities of companies from the following industries: diversified financial services; insurance; banks; capital markets; mortgage real estate investment trusts (“REITs”); consumer finance; and thrifts and mortgage finance. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC (“S&P DJI”) based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research (“BofA Merrill Lynch”) (S&P DJI and BofA Merrill Lynch, collectively, the “Index Provider”) using a “modified market capitalization” methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code” or “IRC”). As of November 30, 2017, the Index was composed of 67 stocks. The Index is sponsored by the Index Provider and compiled by S&P DJI (the “Index Compilation Agent”). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.
Risk [Heading]	rr_RiskHeading	<b>Principal Risks of Investing in the Fund </b>
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions. Financial Sector Risk: The Fund's assets will be concentrated in the financial sector, which means the Fund will be more affected by the performance of the financial sector than a fund that is more diversified. Financial services companies are subject to extensive governmental regulation which may limit both the amounts and types of loans and other financial commitments they can make, the interest rates and fees they can charge, the scope of their activities, the prices they can charge and the amount of capital they must maintain. Profitability is largely dependent on the availability and cost of capital funds and can fluctuate significantly when interest rates change or due to increased competition. In addition, deterioration of the credit markets generally may cause an adverse impact in a broad range of markets, including U.S. and international credit and interbank money markets generally, thereby affecting a wide range of financial institutions and markets. Certain events in the financial sector may cause an unusually high degree of volatility in the financial markets, both domestic and foreign, and cause certain financial services companies to incur large losses. Securities of financial services companies may experience a dramatic decline in value when such companies experience substantial declines in the valuations of their assets, take action to raise capital (such as the issuance of debt or equity securities), or cease operations. Credit losses resulting from financial difficulties of borrowers and financial losses associated with investment activities can negatively impact the sector. Insurance companies may be subject to severe price competition. Adverse economic, business or political developments could adversely affect financial institutions engaged in mortgage finance or other lending or investing activities directly or indirectly connected to the value of real estate. Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time. Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds. Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies. Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	<blockquote><b>Non-Diversification Risk:</b> As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.</blockquote>
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<b>Fund Performance </b>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	1-866-732-8673
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.sectorspdrs.com
Performance Past Does Not Indicate Future [Text]	rr_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 [Heading]	rr_BarChartHeading	<b>Annual Total Returns (years ended 12/31) </b>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Highest Quarterly Return: 35.82% (Q2, 2009) Lowest Quarterly Return: -36.84% (Q4, 2008)
Performance Table Heading	rr_PerformanceTableHeading	<b>Average Annual Total Returns (for periods ending 12/31/17) </b>
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	The after-tax returns presented in the table below are calculated using highest historical individual federal marginal income tax rates 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 will depend on your specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
The Financial Select Sector SPDR Fund | The Financial Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Management fees	rr_ManagementFeesOverAssets	0.03%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.04%
Other expenses	rr_OtherExpensesOverAssets	0.06%
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.13%	[1]
Year 1	rr_ExpenseExampleYear01	$ 13
Year 3	rr_ExpenseExampleYear03	42
Year 5	rr_ExpenseExampleYear05	73
Year 10	rr_ExpenseExampleYear10	$ 166
2008	rr_AnnualReturn2008	(55.21%)
2009	rr_AnnualReturn2009	17.50%
2010	rr_AnnualReturn2010	11.98%
2011	rr_AnnualReturn2011	(17.16%)
2012	rr_AnnualReturn2012	28.51%
2013	rr_AnnualReturn2013	35.37%
2014	rr_AnnualReturn2014	15.03%
2015	rr_AnnualReturn2015	(1.60%)
2016	rr_AnnualReturn2016	22.69%
2017	rr_AnnualReturn2017	22.04%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest Quarterly Return:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	35.82%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest Quarterly Return:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(36.84%)
One Year	rr_AverageAnnualReturnYear01	22.04%
Five Years	rr_AverageAnnualReturnYear05	18.07%
Ten Years	rr_AverageAnnualReturnYear10	3.71%
The Financial Select Sector SPDR Fund | Return After Taxes on Distributions | The Financial Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	21.52%
Five Years	rr_AverageAnnualReturnYear05	16.81%
Ten Years	rr_AverageAnnualReturnYear10	2.93%
The Financial Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares | The Financial Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	12.75%
Five Years	rr_AverageAnnualReturnYear05	14.60%
Ten Years	rr_AverageAnnualReturnYear10	2.79%
The Financial Select Sector SPDR Fund | The Financial Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	22.18%
Five Years	rr_AverageAnnualReturnYear05	18.21%
Ten Years	rr_AverageAnnualReturnYear10	3.79%
The Financial Select Sector SPDR Fund | S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	21.83%
Five Years	rr_AverageAnnualReturnYear05	15.79%
Ten Years	rr_AverageAnnualReturnYear10	8.50%

[1] The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.

XML

The Health Care Select Sector SPDR Fund

<b>Fund Summaries</b><br/><br/><b>The Health Care Select Sector SPDR Fund</b>

<b>Investment Objective </b>

The Health Care Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Health Care Select Sector Index (the “Index”).

<b>Fees and Expenses of the Fund </b>

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.

<b>Annual Fund Operating Expenses </b><br/><br/><b>(expenses that you pay each year as a percentage of the value of your investment):</b>

Annual Fund Operating Expenses	The Health Care Select Sector SPDR Fund The Health Care Select Sector SPDR Fund
Management fees	0.03%
Distribution and service (12b-1) fees	0.04%
Other expenses	0.06%
Total annual Fund operating expenses	0.13%	[1]

<b>Example: </b>

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 sell all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	Year 1	Year 3	Year 5	Year 10
The Health Care Select Sector SPDR Fund | The Health Care Select Sector SPDR Fund | USD ($)	13	42	73	166

<b>Portfolio Turnover: </b>

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 4% of the average value of its portfolio.

<b>The Fund's Principal Investment Strategy </b>

In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index.

Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund).

The Index includes companies that have been identified as Health Care companies by the Global Industry Classification Standard (GICS^®), including securities of companies from the following industries: pharmaceuticals; health care equipment and supplies; health care providers and services; biotechnology; life sciences tools and services; and health care technology. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC (“S&P DJI”) based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research (“BofA Merrill Lynch”) (S&P DJI and BofA Merrill Lynch, collectively, the “Index Provider”) using a “modified market capitalization” methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code” or “IRC”). As of November 30, 2017, the Index was composed of 62 stocks.

The Index is sponsored by the Index Provider and compiled by S&P DJI (the “Index Compilation Agent”). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.

<b>Principal Risks of Investing in the Fund </b>

As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions.

Health Care Sector Risk:  The Fund's assets will be concentrated in the health care sector, which means the Fund will be more affected by the performance of the health care sector than a fund that is more diversified. Companies in the health care sector are subject to extensive government regulation and their profitability can be significantly affected by restrictions on government reimbursement for medical expenses, rising costs of medical products and services, pricing pressure (including price discounting), limited product lines and an increased emphasis on the delivery of healthcare through outpatient services. Companies in the health care sector are heavily dependent on obtaining and defending patents, which may be time consuming and costly, and the expiration of patents may also adversely affect the profitability of these companies. Health care companies are also subject to extensive litigation based on product liability and similar claims. In addition, their products can become obsolete due to industry innovation, changes in technologies or other market developments. Many new products in the health care sector require significant research and development and may be subject to regulatory approvals, all of which may be time consuming and costly with no guarantee that any product will come to market.

Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time.

Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.

Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies.

Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.

<b>Fund Performance </b>

The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.

<b>Annual Total Returns (years ended 12/31) </b>

Highest Quarterly Return: 15.70% (Q1, 2013)
Lowest Quarterly Return: -12.21% (Q4, 2008)

<b>Average Annual Total Returns (for periods ending 12/31/17)</b>

The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.

Average Annual Total Returns - The Health Care Select Sector SPDR Fund	One Year	Five Years	Ten Years
The Health Care Select Sector SPDR Fund	21.70%	17.44%	10.83%
The Health Care Select Sector SPDR Fund | Return After Taxes on Distributions	21.26%	17.01%	10.46%
The Health Care Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares	12.62%	14.09%	8.91%
The Health Care Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)	21.93%	17.64%	11.02%
S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)	21.83%	15.79%	8.50%

[1] The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	SELECT SECTOR SPDR TRUST
Prospectus Date	rr_ProspectusDate	Sep. 24, 2018
The Health Care Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<b>Fund Summaries</b><br/><br/><b>The Health Care Select Sector SPDR Fund</b>
Objective [Heading]	rr_ObjectiveHeading	<b>Investment Objective </b>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Health Care Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Health Care Select Sector Index (the “Index”).
Expense [Heading]	rr_ExpenseHeading	<b>Fees and Expenses of the Fund </b>
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 (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<b>Annual Fund Operating Expenses </b><br/><br/><b>(expenses that you pay each year as a percentage of the value of your investment):</b>
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<b>Portfolio Turnover: </b>
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 4% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	4.00%
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Expenses Restated to Reflect Current [Text]	rr_ExpensesRestatedToReflectCurrent	The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.
Expense Example [Heading]	rr_ExpenseExampleHeading	<b>Example: </b>
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, and then sell all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	<b>The Fund's Principal Investment Strategy </b>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index. Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund). The Index includes companies that have been identified as Health Care companies by the Global Industry Classification Standard (GICS®), including securities of companies from the following industries: pharmaceuticals; health care equipment and supplies; health care providers and services; biotechnology; life sciences tools and services; and health care technology. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC (“S&P DJI”) based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research (“BofA Merrill Lynch”) (S&P DJI and BofA Merrill Lynch, collectively, the “Index Provider”) using a “modified market capitalization” methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code” or “IRC”). As of November 30, 2017, the Index was composed of 62 stocks. The Index is sponsored by the Index Provider and compiled by S&P DJI (the “Index Compilation Agent”). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.
Risk [Heading]	rr_RiskHeading	<b>Principal Risks of Investing in the Fund </b>
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions. Health Care Sector Risk:  The Fund's assets will be concentrated in the health care sector, which means the Fund will be more affected by the performance of the health care sector than a fund that is more diversified. Companies in the health care sector are subject to extensive government regulation and their profitability can be significantly affected by restrictions on government reimbursement for medical expenses, rising costs of medical products and services, pricing pressure (including price discounting), limited product lines and an increased emphasis on the delivery of healthcare through outpatient services. Companies in the health care sector are heavily dependent on obtaining and defending patents, which may be time consuming and costly, and the expiration of patents may also adversely affect the profitability of these companies. Health care companies are also subject to extensive litigation based on product liability and similar claims. In addition, their products can become obsolete due to industry innovation, changes in technologies or other market developments. Many new products in the health care sector require significant research and development and may be subject to regulatory approvals, all of which may be time consuming and costly with no guarantee that any product will come to market. Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time. Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds. Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies. Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	<blockquote><b>Non-Diversification Risk:</b> As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.</blockquote>
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<b>Fund Performance </b>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	1-866-732-8673
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.sectorspdrs.com
Performance Past Does Not Indicate Future [Text]	rr_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 [Heading]	rr_BarChartHeading	<b>Annual Total Returns (years ended 12/31) </b>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Highest Quarterly Return: 15.70% (Q1, 2013) Lowest Quarterly Return: -12.21% (Q4, 2008)
Performance Table Heading	rr_PerformanceTableHeading	<b>Average Annual Total Returns (for periods ending 12/31/17)</b>
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	The after-tax returns presented in the table below are calculated using highest historical individual federal marginal income tax rates 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 will depend on your specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
The Health Care Select Sector SPDR Fund | The Health Care Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Management fees	rr_ManagementFeesOverAssets	0.03%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.04%
Other expenses	rr_OtherExpensesOverAssets	0.06%
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.13%	[1]
Year 1	rr_ExpenseExampleYear01	$ 13
Year 3	rr_ExpenseExampleYear03	42
Year 5	rr_ExpenseExampleYear05	73
Year 10	rr_ExpenseExampleYear10	$ 166
2008	rr_AnnualReturn2008	(23.15%)
2009	rr_AnnualReturn2009	19.81%
2010	rr_AnnualReturn2010	2.92%
2011	rr_AnnualReturn2011	12.42%
2012	rr_AnnualReturn2012	17.53%
2013	rr_AnnualReturn2013	41.24%
2014	rr_AnnualReturn2014	25.18%
2015	rr_AnnualReturn2015	6.86%
2016	rr_AnnualReturn2016	(2.83%)
2017	rr_AnnualReturn2017	21.70%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest Quarterly Return:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Mar. 31, 2013
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	15.70%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest Quarterly Return:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(12.21%)
One Year	rr_AverageAnnualReturnYear01	21.70%
Five Years	rr_AverageAnnualReturnYear05	17.44%
Ten Years	rr_AverageAnnualReturnYear10	10.83%
The Health Care Select Sector SPDR Fund | Return After Taxes on Distributions | The Health Care Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	21.26%
Five Years	rr_AverageAnnualReturnYear05	17.01%
Ten Years	rr_AverageAnnualReturnYear10	10.46%
The Health Care Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares | The Health Care Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	12.62%
Five Years	rr_AverageAnnualReturnYear05	14.09%
Ten Years	rr_AverageAnnualReturnYear10	8.91%
The Health Care Select Sector SPDR Fund | The Health Care Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	21.93%
Five Years	rr_AverageAnnualReturnYear05	17.64%
Ten Years	rr_AverageAnnualReturnYear10	11.02%
The Health Care Select Sector SPDR Fund | S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	21.83%
Five Years	rr_AverageAnnualReturnYear05	15.79%
Ten Years	rr_AverageAnnualReturnYear10	8.50%

[1] The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.

XML

The Industrial Select Sector SPDR Fund

<b>Fund Summaries</b><br/><br/><b>The Industrial Select Sector SPDR Fund</b>

<b>Investment Objective </b>

The Industrial Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Industrial Select Sector Index (the “Index”).

<b>Fees and Expenses of the Fund </b>

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.

<b>Annual Fund Operating Expenses </b><br/><br/><b>(expenses that you pay each year as a percentage of the value of your investment):</b>

Annual Fund Operating Expenses	The Industrial Select Sector SPDR Fund The Industrial Select Sector SPDR Fund
Management fees	0.03%
Distribution and service (12b-1) fees	0.04%
Other expenses	0.06%
Total annual Fund operating expenses	0.13%	[1]

<b>Example: </b>

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 sell all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	Year 1	Year 3	Year 5	Year 10
The Industrial Select Sector SPDR Fund | The Industrial Select Sector SPDR Fund | USD ($)	13	42	73	166

<b>Portfolio Turnover: </b>

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 5% of the average value of its portfolio.

<b>The Fund's Principal Investment Strategy </b>

In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index.

Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund).

The Index includes companies that have been identified as Industrial companies by the Global Industry Classification Standard (GICS^®), including securities of companies from the following industries: aerospace and defense; industrial conglomerates; marine; transportation infrastructure; machinery; road and rail; air freight and logistics; commercial services and supplies; professional services; electrical equipment; construction and engineering; trading companies and distributors; airlines; and building products. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC (“S&P DJI”) based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research (“BofA Merrill Lynch”) (S&P DJI and BofA Merrill Lynch, collectively, the “Index Provider”) using a “modified market capitalization” methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code” or “IRC”). As of November 30, 2017, the Index was composed of 68 stocks.

The Index is sponsored by the Index Provider and compiled by S&P DJI (the “Index Compilation Agent”). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.

<b>Principal Risks of Investing in the Fund </b>

As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions.

Industrial Sector Risk: The Fund's assets will be concentrated in the industrial sector, which means the Fund will be more affected by the performance of the industrial sector than a fund that is more diversified.  Industrial companies are affected by supply and demand both for their specific product or service and for industrial sector products in general. Government regulation, world events, exchange rates and economic conditions, technological developments and liabilities for environmental damage and general civil liabilities will likewise affect the performance of these companies. Aerospace and defense companies, a component of the industrial sector, can be significantly affected by government spending policies because companies involved in this industry rely, to a significant extent, on U.S. and foreign government demand for their products and services. Thus, the financial condition of, and investor interest in, aerospace and defense companies are heavily influenced by governmental defense spending policies which are typically under pressure from efforts to control the U.S. (and other) government budgets. Transportation securities, a component of the industrial sector, are cyclical and have occasional sharp price movements which may result from changes in the economy, fuel prices, labor agreements and insurance costs.

Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time.

Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.

Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies.

Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.

<b>Fund Performance </b>

The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.

<b>Annual Total Returns (years ended 12/31) </b>

Highest Quarterly Return: 20.98% (Q3, 2009)
Lowest Quarterly Return: -23.21% (Q4, 2008)

<b>Average Annual Total Returns (for periods ending 12/31/17) </b>

The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.

Average Annual Total Returns - The Industrial Select Sector SPDR Fund	One Year	Five Years	Ten Years
The Industrial Select Sector SPDR Fund	23.84%	17.15%	9.15%
The Industrial Select Sector SPDR Fund | Return After Taxes on Distributions	23.28%	16.55%	8.67%
The Industrial Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares	13.89%	13.75%	7.37%
The Industrial Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)	24.10%	17.35%	9.33%
S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)	21.83%	15.79%	8.50%

[1] The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	SELECT SECTOR SPDR TRUST
Prospectus Date	rr_ProspectusDate	Sep. 24, 2018
The Industrial Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<b>Fund Summaries</b><br/><br/><b>The Industrial Select Sector SPDR Fund</b>
Objective [Heading]	rr_ObjectiveHeading	<b>Investment Objective </b>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Industrial Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Industrial Select Sector Index (the “Index”).
Expense [Heading]	rr_ExpenseHeading	<b>Fees and Expenses of the Fund </b>
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 (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<b>Annual Fund Operating Expenses </b><br/><br/><b>(expenses that you pay each year as a percentage of the value of your investment):</b>
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<b>Portfolio Turnover: </b>
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 5% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	5.00%
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Expenses Restated to Reflect Current [Text]	rr_ExpensesRestatedToReflectCurrent	The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.
Expense Example [Heading]	rr_ExpenseExampleHeading	<b>Example: </b>
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, and then sell all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	<b>The Fund's Principal Investment Strategy </b>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index. Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund). The Index includes companies that have been identified as Industrial companies by the Global Industry Classification Standard (GICS®), including securities of companies from the following industries: aerospace and defense; industrial conglomerates; marine; transportation infrastructure; machinery; road and rail; air freight and logistics; commercial services and supplies; professional services; electrical equipment; construction and engineering; trading companies and distributors; airlines; and building products. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC (“S&P DJI”) based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research (“BofA Merrill Lynch”) (S&P DJI and BofA Merrill Lynch, collectively, the “Index Provider”) using a “modified market capitalization” methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code” or “IRC”). As of November 30, 2017, the Index was composed of 68 stocks. The Index is sponsored by the Index Provider and compiled by S&P DJI (the “Index Compilation Agent”). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.
Risk [Heading]	rr_RiskHeading	<b>Principal Risks of Investing in the Fund </b>
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions. Industrial Sector Risk: The Fund's assets will be concentrated in the industrial sector, which means the Fund will be more affected by the performance of the industrial sector than a fund that is more diversified.  Industrial companies are affected by supply and demand both for their specific product or service and for industrial sector products in general. Government regulation, world events, exchange rates and economic conditions, technological developments and liabilities for environmental damage and general civil liabilities will likewise affect the performance of these companies. Aerospace and defense companies, a component of the industrial sector, can be significantly affected by government spending policies because companies involved in this industry rely, to a significant extent, on U.S. and foreign government demand for their products and services. Thus, the financial condition of, and investor interest in, aerospace and defense companies are heavily influenced by governmental defense spending policies which are typically under pressure from efforts to control the U.S. (and other) government budgets. Transportation securities, a component of the industrial sector, are cyclical and have occasional sharp price movements which may result from changes in the economy, fuel prices, labor agreements and insurance costs. Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time. Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds. Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies. Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	<blockquote><b>Non-Diversification Risk:</b> As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.</blockquote>
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<b>Fund Performance </b>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	1-866-732-8673
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.sectorspdrs.com
Performance Past Does Not Indicate Future [Text]	rr_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 [Heading]	rr_BarChartHeading	<b>Annual Total Returns (years ended 12/31) </b>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Highest Quarterly Return: 20.98% (Q3, 2009) Lowest Quarterly Return: -23.21% (Q4, 2008)
Performance Table Heading	rr_PerformanceTableHeading	<b>Average Annual Total Returns (for periods ending 12/31/17) </b>
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	The after-tax returns presented in the table below are calculated using highest historical individual federal marginal income tax rates 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 will depend on your specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
The Industrial Select Sector SPDR Fund | The Industrial Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Management fees	rr_ManagementFeesOverAssets	0.03%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.04%
Other expenses	rr_OtherExpensesOverAssets	0.06%
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.13%	[1]
Year 1	rr_ExpenseExampleYear01	$ 13
Year 3	rr_ExpenseExampleYear03	42
Year 5	rr_ExpenseExampleYear05	73
Year 10	rr_ExpenseExampleYear10	$ 166
2008	rr_AnnualReturn2008	(38.88%)
2009	rr_AnnualReturn2009	22.63%
2010	rr_AnnualReturn2010	27.65%
2011	rr_AnnualReturn2011	(1.02%)
2012	rr_AnnualReturn2012	14.86%
2013	rr_AnnualReturn2013	40.44%
2014	rr_AnnualReturn2014	10.45%
2015	rr_AnnualReturn2015	(4.25%)
2016	rr_AnnualReturn2016	19.95%
2017	rr_AnnualReturn2017	23.84%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest Quarterly Return:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Sep. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	20.98%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest Quarterly Return:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(23.21%)
One Year	rr_AverageAnnualReturnYear01	23.84%
Five Years	rr_AverageAnnualReturnYear05	17.15%
Ten Years	rr_AverageAnnualReturnYear10	9.15%
The Industrial Select Sector SPDR Fund | Return After Taxes on Distributions | The Industrial Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	23.28%
Five Years	rr_AverageAnnualReturnYear05	16.55%
Ten Years	rr_AverageAnnualReturnYear10	8.67%
The Industrial Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares | The Industrial Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	13.89%
Five Years	rr_AverageAnnualReturnYear05	13.75%
Ten Years	rr_AverageAnnualReturnYear10	7.37%
The Industrial Select Sector SPDR Fund | The Industrial Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	24.10%
Five Years	rr_AverageAnnualReturnYear05	17.35%
Ten Years	rr_AverageAnnualReturnYear10	9.33%
The Industrial Select Sector SPDR Fund | S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	21.83%
Five Years	rr_AverageAnnualReturnYear05	15.79%
Ten Years	rr_AverageAnnualReturnYear10	8.50%

[1] The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.

XML

The Materials Select Sector SPDR Fund

<b>Fund Summaries </b><br/><br/><b>The Materials Select Sector SPDR Fund</b>

<b>Investment Objective </b>

The Materials Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Materials Select Sector Index (the “Index”).

<b>Fees and Expenses of the Fund </b>

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.

<b>Annual Fund Operating Expenses </b><br/><br/><b>(expenses that you pay each year as a percentage of the value of your investment):</b>

Annual Fund Operating Expenses	The Materials Select Sector SPDR Fund The Materials Select Sector SPDR Fund
Management fees	0.03%
Distribution and service (12b-1) fees	0.04%
Other expenses	0.06%
Total annual Fund operating expenses	0.13%	[1]

<b>Example: </b>

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 sell all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	Year 1	Year 3	Year 5	Year 10
The Materials Select Sector SPDR Fund | The Materials Select Sector SPDR Fund | USD ($)	13	42	73	166

<b>Portfolio Turnover: </b>

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 10% of the average value of its portfolio.

<b>The Fund's Principal Investment Strategy </b>

In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index.

Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund).

The Index includes companies that have been identified as Materials companies by the Global Industry Classification Standard (GICS^®), including securities of companies from the following industries: chemicals; metals and mining; paper and forest products; containers and packaging; and construction materials. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC (“S&P DJI”) based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research (“BofA Merrill Lynch”) (S&P DJI and BofA Merrill Lynch, collectively, the “Index Provider”) using a “modified market capitalization” methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code” or “IRC”). As of November 30, 2017, the Index was composed of 25 stocks.

The Index is sponsored by the Index Provider and compiled by S&P DJI (the “Index Compilation Agent”). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.

<b>Principal Risks of Investing in the Fund </b>

As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions.

Materials Sector Risk: The Fund's assets will be concentrated in the materials sector, which means the Fund will be more affected by the performance of the materials sector than a fund that is more diversified. Many materials companies are significantly affected by the level and volatility of commodity prices, exchange rates, import controls, worldwide competition, environmental policies and consumer demand. At times, worldwide production of industrial materials has exceeded demand as a result of over-building or economic downturns, leading to poor investment returns or losses. Other risks may include liabilities for environmental damage and general civil liabilities, depletion of resources, and mandated expenditures for safety and pollution control. The materials sector may also be affected by economic cycles, technical progress, labor relations, and government regulations.

Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time.

Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.

Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies.

Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.

<b>Fund Performance </b>

The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.

<b>Annual Total Returns (years ended 12/31) </b>

Highest Quarterly Return: 20.62% (Q3, 2009)
Lowest Quarterly Return: -30.50% (Q4, 2008)

<b>Average Annual Total Returns (for periods ending 12/31/17)</b>

The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.

Average Annual Total Returns - The Materials Select Sector SPDR Fund	One Year	Five Years	Ten Years
The Materials Select Sector SPDR Fund	23.94%	12.29%	6.20%
The Materials Select Sector SPDR Fund | Return After Taxes on Distributions	23.39%	11.69%	5.70%
The Materials Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares	13.90%	9.66%	4.87%
The Materials Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)	23.93%	12.44%	6.35%
S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)	21.83%	15.79%	8.50%

[1] The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	SELECT SECTOR SPDR TRUST
Prospectus Date	rr_ProspectusDate	Sep. 24, 2018
The Materials Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<b>Fund Summaries </b><br/><br/><b>The Materials Select Sector SPDR Fund</b>
Objective [Heading]	rr_ObjectiveHeading	<b>Investment Objective </b>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Materials Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Materials Select Sector Index (the “Index”).
Expense [Heading]	rr_ExpenseHeading	<b>Fees and Expenses of the Fund </b>
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 (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<b>Annual Fund Operating Expenses </b><br/><br/><b>(expenses that you pay each year as a percentage of the value of your investment):</b>
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<b>Portfolio Turnover: </b>
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 10% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	10.00%
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Expenses Restated to Reflect Current [Text]	rr_ExpensesRestatedToReflectCurrent	The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.
Expense Example [Heading]	rr_ExpenseExampleHeading	<b>Example: </b>
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, and then sell all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	<b>The Fund's Principal Investment Strategy </b>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index. Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund). The Index includes companies that have been identified as Materials companies by the Global Industry Classification Standard (GICS®), including securities of companies from the following industries: chemicals; metals and mining; paper and forest products; containers and packaging; and construction materials. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC (“S&P DJI”) based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research (“BofA Merrill Lynch”) (S&P DJI and BofA Merrill Lynch, collectively, the “Index Provider”) using a “modified market capitalization” methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code” or “IRC”). As of November 30, 2017, the Index was composed of 25 stocks. The Index is sponsored by the Index Provider and compiled by S&P DJI (the “Index Compilation Agent”). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.
Risk [Heading]	rr_RiskHeading	<b>Principal Risks of Investing in the Fund </b>
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions. Materials Sector Risk: The Fund's assets will be concentrated in the materials sector, which means the Fund will be more affected by the performance of the materials sector than a fund that is more diversified. Many materials companies are significantly affected by the level and volatility of commodity prices, exchange rates, import controls, worldwide competition, environmental policies and consumer demand. At times, worldwide production of industrial materials has exceeded demand as a result of over-building or economic downturns, leading to poor investment returns or losses. Other risks may include liabilities for environmental damage and general civil liabilities, depletion of resources, and mandated expenditures for safety and pollution control. The materials sector may also be affected by economic cycles, technical progress, labor relations, and government regulations. Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time. Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds. Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies. Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	<blockquote><b>Non-Diversification Risk:</b> As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.</blockquote>
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<b>Fund Performance </b>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	1-866-732-8673
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.sectorspdrs.com
Performance Past Does Not Indicate Future [Text]	rr_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 [Heading]	rr_BarChartHeading	<b>Annual Total Returns (years ended 12/31) </b>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Highest Quarterly Return: 20.62% (Q3, 2009) Lowest Quarterly Return: -30.50% (Q4, 2008)
Performance Table Heading	rr_PerformanceTableHeading	<b>Average Annual Total Returns (for periods ending 12/31/17)</b>
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	The after-tax returns presented in the table below are calculated using highest historical individual federal marginal income tax rates 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 will depend on your specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
The Materials Select Sector SPDR Fund | The Materials Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Management fees	rr_ManagementFeesOverAssets	0.03%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.04%
Other expenses	rr_OtherExpensesOverAssets	0.06%
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.13%	[1]
Year 1	rr_ExpenseExampleYear01	$ 13
Year 3	rr_ExpenseExampleYear03	42
Year 5	rr_ExpenseExampleYear05	73
Year 10	rr_ExpenseExampleYear10	$ 166
2008	rr_AnnualReturn2008	(43.99%)
2009	rr_AnnualReturn2009	48.47%
2010	rr_AnnualReturn2010	20.40%
2011	rr_AnnualReturn2011	(10.97%)
2012	rr_AnnualReturn2012	14.74%
2013	rr_AnnualReturn2013	25.83%
2014	rr_AnnualReturn2014	7.31%
2015	rr_AnnualReturn2015	(8.58%)
2016	rr_AnnualReturn2016	16.66%
2017	rr_AnnualReturn2017	23.94%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest Quarterly Return:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Sep. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	20.62%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest Quarterly Return:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(30.50%)
One Year	rr_AverageAnnualReturnYear01	23.94%
Five Years	rr_AverageAnnualReturnYear05	12.29%
Ten Years	rr_AverageAnnualReturnYear10	6.20%
The Materials Select Sector SPDR Fund | Return After Taxes on Distributions | The Materials Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	23.39%
Five Years	rr_AverageAnnualReturnYear05	11.69%
Ten Years	rr_AverageAnnualReturnYear10	5.70%
The Materials Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares | The Materials Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	13.90%
Five Years	rr_AverageAnnualReturnYear05	9.66%
Ten Years	rr_AverageAnnualReturnYear10	4.87%
The Materials Select Sector SPDR Fund | The Materials Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	23.93%
Five Years	rr_AverageAnnualReturnYear05	12.44%
Ten Years	rr_AverageAnnualReturnYear10	6.35%
The Materials Select Sector SPDR Fund | S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	21.83%
Five Years	rr_AverageAnnualReturnYear05	15.79%
Ten Years	rr_AverageAnnualReturnYear10	8.50%

[1] The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.

XML

The Real Estate Select Sector SPDR Fund

<b>Fund Summaries </b><br/><br/><b>The Real Estate Select Sector SPDR Fund</b>

<b>Investment Objective </b>

The Real Estate Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Real Estate Select Sector Index (the “Index”).

<b>Fees and Expenses of the Fund </b>

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.

<b>Annual Fund Operating Expenses </b><br/><br/><b>(expenses that you pay each year as a percentage of the value of your investment): </b>

Annual Fund Operating Expenses	The Real Estate Select Sector SPDR Fund The Real Estate Select Sector SPDR Fund
Management fees	0.03%
Distribution and service (12b-1) fees	0.04%
Other expenses	0.06%
Total annual Fund operating expenses	0.13%	[1],[2]

<b>Example: </b>

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 sell all of your Fund 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. The calculation of costs for the one-year period takes into account the effect of any current contractual fee waivers and/or reimbursements; and the calculation of costs for the remaining periods takes such fee waivers and/or reimbursements into account only for the first year of each such period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	Year 1	Year 3	Year 5	Year 10
The Real Estate Select Sector SPDR Fund | The Real Estate Select Sector SPDR Fund | USD ($)	13	42	73	166

<b>Portfolio Turnover: </b>

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 16% of the average value of its portfolio.

<b>The Fund's Principal Investment Strategy </b>

In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index.

Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund).

The Index includes companies that have been identified as Real Estate companies by the Global Industry Classification Standard (GICS^®), including securities of companies from the following industries: real estate management and development and real estate investment trusts (“REITs”), excluding mortgage REITs. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC (“S&P DJI”) based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research (“BofA Merrill Lynch”) (S&P DJI and BofA Merrill Lynch, collectively, the “Index Provider”) using a “modified market capitalization” methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code” or “IRC”). As of November 30, 2017, the Index was composed of 33 stocks.

The Index is sponsored by the Index Provider and compiled by S&P DJI (the “Index Compilation Agent”). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.

<b>Principal Risks of Investing in the Fund </b>

As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions.

Real Estate Sector Risk: The Fund's assets will be concentrated in the real estate sector, which means the Fund will be more affected by the performance of the real estate sector than a fund that is more diversified. An investment in a real property company may be subject to risks similar to those associated with direct ownership of real estate, including, by way of example, the possibility of declines in the value of real estate, losses from casualty or condemnation, and changes in local and general economic conditions, supply and demand, interest rates, environmental liability, zoning laws, regulatory limitations on rents, property taxes, and operating expenses. Some real property companies have limited diversification because they invest in a limited number of properties, a narrow geographic area, or a single type of property.

REIT Risk: REITs are subject to the risks associated with investing in the securities of real property companies. In particular, REITs may be affected by changes in the values of the underlying properties that they own or operate. Further, REITs are dependent upon specialized management skills, and their investments may be concentrated in relatively few properties, or in a small geographic area or a single property type. REITs are also subject to heavy cash flow dependency and, as a result, are particularly reliant on the proper functioning of capital markets. A variety of economic and other factors may adversely affect a lessee's ability to meet its obligations to a REIT. In the event of a default by a lessee, the REIT may experience delays in enforcing its rights as a lessor and may incur substantial costs associated in protecting its investments. In addition, a REIT could fail to qualify for favorable tax or regulatory treatment.

Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time.

Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.

Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies.

Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.

<b>Fund Performance </b>

The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.

<b>Annual Total Return (year ended 12/31) </b>

Highest Quarterly Return: 5.67% (Q2, 2016)
Lowest Quarterly Return: -4.43% (Q4, 2016)

<b>Average Annual Total Returns (for periods ending 12/31/17) </b>

The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.

Average Annual Total Returns - The Real Estate Select Sector SPDR Fund	One Year	Since Inception	Inception Date
The Real Estate Select Sector SPDR Fund	10.70%	8.28%	Oct. 07, 2015
The Real Estate Select Sector SPDR Fund | Return After Taxes on Distributions	9.13%	6.52%	Oct. 07, 2015
The Real Estate Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares	6.03%	5.53%	Oct. 07, 2015
The Real Estate Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)	10.85%	8.45%	Oct. 07, 2015
S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)	21.83%	16.39%	Oct. 07, 2015

[1] SSGA Funds Management, Inc. (the “Adviser”) has contractually agreed to waive a portion of its advisory fee and reimburse certain expenses, until January 31, 2019, so that the annual Fund operating expenses of the Fund are limited to no more than 0.1345% of the Fund's average daily net assets (exclusive of non-recurring account fees and expenses). The Adviser may continue such waiver and/or reimbursement from year to year, but there is no guarantee that the Adviser will do so after January 31, 2019. The waiver and/or reimbursement may not be terminated prior to January 31, 2019 except with the approval of The Select Sector SPDR Trust's Board of Trustees.

[2] The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	SELECT SECTOR SPDR TRUST
Prospectus Date	rr_ProspectusDate	Sep. 24, 2018
The Real Estate Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<b>Fund Summaries </b><br/><br/><b>The Real Estate Select Sector SPDR Fund</b>
Objective [Heading]	rr_ObjectiveHeading	<b>Investment Objective </b>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Real Estate Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Real Estate Select Sector Index (the “Index”).
Expense [Heading]	rr_ExpenseHeading	<b>Fees and Expenses of the Fund </b>
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 (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<b>Annual Fund Operating Expenses </b><br/><br/><b>(expenses that you pay each year as a percentage of the value of your investment): </b>
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	January 31, 2019
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<b>Portfolio Turnover: </b>
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 16% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	16.00%
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Expenses Restated to Reflect Current [Text]	rr_ExpensesRestatedToReflectCurrent	The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.
Expense Example [Heading]	rr_ExpenseExampleHeading	<b>Example: </b>
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, and then sell all of your Fund 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. The calculation of costs for the one-year period takes into account the effect of any current contractual fee waivers and/or reimbursements; and the calculation of costs for the remaining periods takes such fee waivers and/or reimbursements into account only for the first year of each such period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	<b>The Fund's Principal Investment Strategy </b>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index. Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund). The Index includes companies that have been identified as Real Estate companies by the Global Industry Classification Standard (GICS®), including securities of companies from the following industries: real estate management and development and real estate investment trusts (“REITs”), excluding mortgage REITs. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC (“S&P DJI”) based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research (“BofA Merrill Lynch”) (S&P DJI and BofA Merrill Lynch, collectively, the “Index Provider”) using a “modified market capitalization” methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code” or “IRC”). As of November 30, 2017, the Index was composed of 33 stocks. The Index is sponsored by the Index Provider and compiled by S&P DJI (the “Index Compilation Agent”). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.
Risk [Heading]	rr_RiskHeading	<b>Principal Risks of Investing in the Fund </b>
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions. Real Estate Sector Risk: The Fund's assets will be concentrated in the real estate sector, which means the Fund will be more affected by the performance of the real estate sector than a fund that is more diversified. An investment in a real property company may be subject to risks similar to those associated with direct ownership of real estate, including, by way of example, the possibility of declines in the value of real estate, losses from casualty or condemnation, and changes in local and general economic conditions, supply and demand, interest rates, environmental liability, zoning laws, regulatory limitations on rents, property taxes, and operating expenses. Some real property companies have limited diversification because they invest in a limited number of properties, a narrow geographic area, or a single type of property. REIT Risk: REITs are subject to the risks associated with investing in the securities of real property companies. In particular, REITs may be affected by changes in the values of the underlying properties that they own or operate. Further, REITs are dependent upon specialized management skills, and their investments may be concentrated in relatively few properties, or in a small geographic area or a single property type. REITs are also subject to heavy cash flow dependency and, as a result, are particularly reliant on the proper functioning of capital markets. A variety of economic and other factors may adversely affect a lessee's ability to meet its obligations to a REIT. In the event of a default by a lessee, the REIT may experience delays in enforcing its rights as a lessor and may incur substantial costs associated in protecting its investments. In addition, a REIT could fail to qualify for favorable tax or regulatory treatment. Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time. Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds. Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies. Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	<blockquote><b>Non-Diversification Risk:</b> As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.</blockquote>
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<b>Fund Performance </b>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	1-866-732-8673
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.sectorspdrs.com
Performance Past Does Not Indicate Future [Text]	rr_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 [Heading]	rr_BarChartHeading	<b>Annual Total Return (year ended 12/31) </b>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Highest Quarterly Return: 5.67% (Q2, 2016) Lowest Quarterly Return: -4.43% (Q4, 2016)
Performance Table Heading	rr_PerformanceTableHeading	<b>Average Annual Total Returns (for periods ending 12/31/17) </b>
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	The after-tax returns presented in the table below are calculated using highest historical individual federal marginal income tax rates 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 will depend on your specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
The Real Estate Select Sector SPDR Fund | The Real Estate Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Management fees	rr_ManagementFeesOverAssets	0.03%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.04%
Other expenses	rr_OtherExpensesOverAssets	0.06%
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.13%	[1],[2]
Year 1	rr_ExpenseExampleYear01	$ 13
Year 3	rr_ExpenseExampleYear03	42
Year 5	rr_ExpenseExampleYear05	73
Year 10	rr_ExpenseExampleYear10	$ 166
2016	rr_AnnualReturn2016	3.19%
2017	rr_AnnualReturn2017	10.70%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest Quarterly Return:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2016
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	5.67%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest Quarterly Return:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2016
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(4.43%)
One Year	rr_AverageAnnualReturnYear01	10.70%
Since Inception	rr_AverageAnnualReturnSinceInception	8.28%
Inception Date	rr_AverageAnnualReturnInceptionDate	Oct. 07, 2015
The Real Estate Select Sector SPDR Fund | Return After Taxes on Distributions | The Real Estate Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	9.13%
Since Inception	rr_AverageAnnualReturnSinceInception	6.52%
Inception Date	rr_AverageAnnualReturnInceptionDate	Oct. 07, 2015
The Real Estate Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares | The Real Estate Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	6.03%
Since Inception	rr_AverageAnnualReturnSinceInception	5.53%
Inception Date	rr_AverageAnnualReturnInceptionDate	Oct. 07, 2015
The Real Estate Select Sector SPDR Fund | The Real Estate Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	10.85%
Since Inception	rr_AverageAnnualReturnSinceInception	8.45%
Inception Date	rr_AverageAnnualReturnInceptionDate	Oct. 07, 2015
The Real Estate Select Sector SPDR Fund | S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	21.83%
Since Inception	rr_AverageAnnualReturnSinceInception	16.39%
Inception Date	rr_AverageAnnualReturnInceptionDate	Oct. 07, 2015

[1] SSGA Funds Management, Inc. (the “Adviser”) has contractually agreed to waive a portion of its advisory fee and reimburse certain expenses, until January 31, 2019, so that the annual Fund operating expenses of the Fund are limited to no more than 0.1345% of the Fund's average daily net assets (exclusive of non-recurring account fees and expenses). The Adviser may continue such waiver and/or reimbursement from year to year, but there is no guarantee that the Adviser will do so after January 31, 2019. The waiver and/or reimbursement may not be terminated prior to January 31, 2019 except with the approval of The Select Sector SPDR Trust's Board of Trustees.

[2] The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.

XML

The Technology Select Sector SPDR Fund

<b>Fund Summaries <br/><br/>The Technology Select Sector SPDR Fund</b>

<b>Investment Objective </b>

The Technology Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Technology Select Sector Index (the “Index”).

<b>Fees and Expenses of the Fund </b>

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.

<b>Annual Fund Operating Expenses <br/><br/> (expenses that you pay each year as a percentage of the value of your investment):</b>

Annual Fund Operating Expenses	The Technology Select Sector SPDR Fund The Technology Select Sector SPDR Fund
Management fees	0.03%
Distribution and service (12b-1) fees	0.04%
Other expenses	0.06%
Total annual Fund operating expenses	0.13%	[1]

<b>Example: </b>

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 sell all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	Year 1	Year 3	Year 5	Year 10
The Technology Select Sector SPDR Fund | The Technology Select Sector SPDR Fund | USD ($)	13	42	73	166

<b>Portfolio Turnover: </b>

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 4% of the average value of its portfolio.

<b>The Fund's Principal Investment Strategy </b>

In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index.

Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund).

The Index includes companies that have been identified as Information Technology companies by the Global Industry Classification Standard (GICS^®), including securities of companies from the following industries: technology hardware, storage, and peripherals; software; communications equipment; semiconductors and semiconductor equipment; IT services; and electronic equipment, instruments and components. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC (“S&P DJI”) based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research (“BofA Merrill Lynch”) (S&P DJI and BofA Merrill Lynch, collectively, the “Index Provider”) using a “modified market capitalization” methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code” or “IRC”). As of November 30, 2017, the Index was composed of 72 stocks.

The Index is sponsored by the Index Provider and compiled by S&P DJI (the “Index Compilation Agent”). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.

<b>Principal Risks of Investing in the Fund </b>

As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions.

Technology Sector Risk: The Fund's assets will be concentrated in the technology sector, which means the Fund will be more affected by the performance of the technology sector than a fund that is more diversified. Market or economic factors impacting technology companies and companies that rely heavily on technological advances could have a major effect on the value of the Fund's investments. The value of stocks of technology companies and companies that rely heavily on technology is particularly vulnerable to rapid changes in technology product cycles, rapid product obsolescence, government regulation and competition, both domestically and internationally, including competition from foreign competitors with lower production costs. Stocks of technology companies and companies that rely heavily on technology, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market. Technology companies are heavily dependent on patent and intellectual property rights, the loss or impairment of which may adversely affect profitability. Additionally, companies in the technology sector may face dramatic and often unpredictable changes in growth rates and competition for the services of qualified personnel.

Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time.

Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.

Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies.

Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.

<b>Fund Performance </b>

The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.

<b>Annual Total Returns (years ended 12/31) </b>

Highest Quarterly Return: 18.80% (Q1, 2012)
Lowest Quarterly Return: -21.89% (Q4, 2008)

<b>Average Annual Total Returns (for periods ending 12/31/17)</b>

The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.

Average Annual Total Returns - The Technology Select Sector SPDR Fund	One Year	Five Years	Ten Years
The Technology Select Sector SPDR Fund	34.28%	19.29%	10.95%
The Technology Select Sector SPDR Fund | Return After Taxes on Distributions	33.80%	18.79%	10.59%
The Technology Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares	19.73%	15.60%	8.99%
The Technology Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)	34.57%	19.52%	11.16%
S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)	21.83%	15.79%	8.50%

[1] The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	SELECT SECTOR SPDR TRUST
Prospectus Date	rr_ProspectusDate	Sep. 24, 2018
The Technology Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<b>Fund Summaries <br/><br/>The Technology Select Sector SPDR Fund</b>
Objective [Heading]	rr_ObjectiveHeading	<b>Investment Objective </b>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Technology Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Technology Select Sector Index (the “Index”).
Expense [Heading]	rr_ExpenseHeading	<b>Fees and Expenses of the Fund </b>
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 (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<b>Annual Fund Operating Expenses <br/><br/> (expenses that you pay each year as a percentage of the value of your investment):</b>
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<b>Portfolio Turnover: </b>
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 4% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	4.00%
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Expenses Restated to Reflect Current [Text]	rr_ExpensesRestatedToReflectCurrent	The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.
Expense Example [Heading]	rr_ExpenseExampleHeading	<b>Example: </b>
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, and then sell all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	<b>The Fund's Principal Investment Strategy </b>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index. Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund). The Index includes companies that have been identified as Information Technology companies by the Global Industry Classification Standard (GICS®), including securities of companies from the following industries: technology hardware, storage, and peripherals; software; communications equipment; semiconductors and semiconductor equipment; IT services; and electronic equipment, instruments and components. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC (“S&P DJI”) based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research (“BofA Merrill Lynch”) (S&P DJI and BofA Merrill Lynch, collectively, the “Index Provider”) using a “modified market capitalization” methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code” or “IRC”). As of November 30, 2017, the Index was composed of 72 stocks. The Index is sponsored by the Index Provider and compiled by S&P DJI (the “Index Compilation Agent”). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.
Risk [Heading]	rr_RiskHeading	<b>Principal Risks of Investing in the Fund </b>
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions. Technology Sector Risk: The Fund's assets will be concentrated in the technology sector, which means the Fund will be more affected by the performance of the technology sector than a fund that is more diversified. Market or economic factors impacting technology companies and companies that rely heavily on technological advances could have a major effect on the value of the Fund's investments. The value of stocks of technology companies and companies that rely heavily on technology is particularly vulnerable to rapid changes in technology product cycles, rapid product obsolescence, government regulation and competition, both domestically and internationally, including competition from foreign competitors with lower production costs. Stocks of technology companies and companies that rely heavily on technology, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market. Technology companies are heavily dependent on patent and intellectual property rights, the loss or impairment of which may adversely affect profitability. Additionally, companies in the technology sector may face dramatic and often unpredictable changes in growth rates and competition for the services of qualified personnel. Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time. Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds. Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies. Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	<blockquote><b>Non-Diversification Risk:</b> As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.</blockquote>
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<b>Fund Performance </b>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	1-866-732-8673
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.sectorspdrs.com
Performance Past Does Not Indicate Future [Text]	rr_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 [Heading]	rr_BarChartHeading	<b>Annual Total Returns (years ended 12/31) </b>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Highest Quarterly Return: 18.80% (Q1, 2012) Lowest Quarterly Return: -21.89% (Q4, 2008)
Performance Table Heading	rr_PerformanceTableHeading	<b>Average Annual Total Returns (for periods ending 12/31/17)</b>
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	The after-tax returns presented in the table below are calculated using highest historical individual federal marginal income tax rates 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 will depend on your specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
The Technology Select Sector SPDR Fund | The Technology Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Management fees	rr_ManagementFeesOverAssets	0.03%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.04%
Other expenses	rr_OtherExpensesOverAssets	0.06%
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.13%	[1]
Year 1	rr_ExpenseExampleYear01	$ 13
Year 3	rr_ExpenseExampleYear03	42
Year 5	rr_ExpenseExampleYear05	73
Year 10	rr_ExpenseExampleYear10	$ 166
2008	rr_AnnualReturn2008	(41.39%)
2009	rr_AnnualReturn2009	50.94%
2010	rr_AnnualReturn2010	11.62%
2011	rr_AnnualReturn2011	2.67%
2012	rr_AnnualReturn2012	15.46%
2013	rr_AnnualReturn2013	25.97%
2014	rr_AnnualReturn2014	17.75%
2015	rr_AnnualReturn2015	5.63%
2016	rr_AnnualReturn2016	14.82%
2017	rr_AnnualReturn2017	34.28%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest Quarterly Return:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Mar. 31, 2012
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	18.80%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest Quarterly Return:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(21.89%)
One Year	rr_AverageAnnualReturnYear01	34.28%
Five Years	rr_AverageAnnualReturnYear05	19.29%
Ten Years	rr_AverageAnnualReturnYear10	10.95%
The Technology Select Sector SPDR Fund | Return After Taxes on Distributions | The Technology Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	33.80%
Five Years	rr_AverageAnnualReturnYear05	18.79%
Ten Years	rr_AverageAnnualReturnYear10	10.59%
The Technology Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares | The Technology Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	19.73%
Five Years	rr_AverageAnnualReturnYear05	15.60%
Ten Years	rr_AverageAnnualReturnYear10	8.99%
The Technology Select Sector SPDR Fund | The Technology Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	34.57%
Five Years	rr_AverageAnnualReturnYear05	19.52%
Ten Years	rr_AverageAnnualReturnYear10	11.16%
The Technology Select Sector SPDR Fund | S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	21.83%
Five Years	rr_AverageAnnualReturnYear05	15.79%
Ten Years	rr_AverageAnnualReturnYear10	8.50%

[1] The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.

XML

The Utilities Select Sector SPDR Fund

<b>Fund Summaries </b><br/><br/><b>The Utilities Select Sector SPDR Fund</b>

<b>Investment Objective </b>

The Utilities Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Utilities Select Sector Index (the “Index”).

<b>Fees and Expenses of the Fund </b>

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.

<b>Annual Fund Operating Expenses <br/><br/> (expenses that you pay each year as a percentage of the value of your investment): </b>

Annual Fund Operating Expenses	The Utilities Select Sector SPDR Fund The Utilities Select Sector SPDR Fund
Management fees	0.03%
Distribution and service (12b-1) fees	0.04%
Other expenses	0.06%
Total annual Fund operating expenses	0.13%	[1]

<b>Example: </b>

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 sell all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	Year 1	Year 3	Year 5	Year 10
The Utilities Select Sector SPDR Fund | The Utilities Select Sector SPDR Fund | USD ($)	13	42	73	166

<b>Portfolio Turnover: </b>

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 2% of the average value of its portfolio.

<b>The Fund's Principal Investment Strategy </b>

In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index.

Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund).

The Index includes companies that have been identified as Utilities companies by the Global Industry Classification Standard (GICS^®), including securities of companies from the following industries: electric utilities; water utilities; multi-utilities; independent power and renewable electricity producers; and gas utilities. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC (“S&P DJI”) based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research (“BofA Merrill Lynch”) (S&P DJI and BofA Merrill Lynch, collectively, the “Index Provider”) using a “modified market capitalization” methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code” or “IRC”). As of November 30, 2017, the Index was composed of 28 stocks.

The Index is sponsored by the Index Provider and compiled by S&P DJI (the “Index Compilation Agent”). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.

<b>Principal Risks of Investing in the Fund </b>

As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions.

Utilities Sector Risk: The Fund's assets will be concentrated in the utilities sector, which means the Fund will be more affected by the performance of the utilities sector than a fund that is more diversified. Utility companies are affected by supply and demand, operating costs, government regulation, environmental factors, liabilities for environmental damage and general civil liabilities, and rate caps or rate changes. Although rate changes of a regulated utility usually fluctuate in approximate correlation with financing costs, due to political and regulatory factors rate changes ordinarily occur only following a delay after the changes in financing costs. This factor will tend to favorably affect a regulated utility company's earnings and dividends in times of decreasing costs, but conversely, will tend to adversely affect earnings and dividends when costs are rising. The value of regulated utility equity securities may tend to have an inverse relationship to the movement of interest rates. Certain utility companies have experienced full or partial deregulation in recent years. These utility companies are frequently more similar to industrial companies in that they are subject to greater competition and have been permitted by regulators to diversify outside of their original geographic regions and their traditional lines of business. These opportunities may permit certain utility companies to earn more than their traditional regulated rates of return. Some companies, however, may be forced to defend their core business and may be less profitable. In addition, natural disasters, terrorist attacks, government intervention or other factors may render a utility company's equipment unusable or obsolete and negatively impact profitability.

Among the risks that may affect utility companies are the following: risks of increases in fuel and other operating costs; the high cost of borrowing to finance capital construction during inflationary periods; restrictions on operations and increased costs and delays associated with compliance with environmental and nuclear safety regulations; and the difficulties involved in obtaining natural gas for resale or fuel for generating electricity at reasonable prices. Other risks include those related to the construction and operation of nuclear power plants, the effects of energy conservation and the effects of regulatory changes.

Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time.

Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.

Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies.

Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.

<b>Fund Performance </b>

The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.

<b>Annual Total Returns (years ended 12/31) </b>

Highest Quarterly Return: 15.47% (Q1, 2016)
Lowest Quarterly Return: -18.01% (Q3, 2008)

<b>Average Annual Total Returns (for periods ending 12/31/17) </b>

The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.

Average Annual Total Returns - The Utilities Select Sector SPDR Fund	One Year	Five Years	Ten Years
The Utilities Select Sector SPDR Fund	12.02%	12.43%	6.08%
The Utilities Select Sector SPDR Fund | Return After Taxes on Distributions	11.14%	11.47%	5.29%
The Utilities Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares	7.51%	9.76%	4.75%
The Utilities Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)	12.10%	12.64%	6.29%
S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)	21.83%	15.79%	8.50%

[1] The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	SELECT SECTOR SPDR TRUST
Prospectus Date	rr_ProspectusDate	Sep. 24, 2018
The Utilities Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<b>Fund Summaries </b><br/><br/><b>The Utilities Select Sector SPDR Fund</b>
Objective [Heading]	rr_ObjectiveHeading	<b>Investment Objective </b>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Utilities Select Sector SPDR Fund (the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the price and yield performance of publicly traded equity securities of companies in the Utilities Select Sector Index (the “Index”).
Expense [Heading]	rr_ExpenseHeading	<b>Fees and Expenses of the Fund </b>
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 (“Fund Shares”). This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<b>Annual Fund Operating Expenses <br/><br/> (expenses that you pay each year as a percentage of the value of your investment): </b>
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<b>Portfolio Turnover: </b>
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 2% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	2.00%
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	This table and the Example below reflect the expenses of the Fund and do not reflect brokerage commissions you may pay on purchases and sales of Fund Shares.
Expenses Restated to Reflect Current [Text]	rr_ExpensesRestatedToReflectCurrent	The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.
Expense Example [Heading]	rr_ExpenseExampleHeading	<b>Example: </b>
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, and then sell all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	<b>The Fund's Principal Investment Strategy </b>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	In seeking to track the performance of the Index, the Fund employs a replication strategy, which means that the Fund typically invests in substantially all of the securities represented in the Index in approximately the same proportions as the Index. Under normal market conditions, the Fund generally invests substantially all, but at least 95%, of its total assets in the securities comprising the Index. The Fund will provide shareholders with at least 60 days' notice prior to any material change in this 95% investment policy. In addition, the Fund may invest in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund). The Index includes companies that have been identified as Utilities companies by the Global Industry Classification Standard (GICS®), including securities of companies from the following industries: electric utilities; water utilities; multi-utilities; independent power and renewable electricity producers; and gas utilities. The Index is one of eleven Select Sector Indexes developed and maintained in accordance with the following criteria: (1) each of the component securities in the Index is a constituent company of the S&P 500 Index; and (2) the Index is calculated by S&P Dow Jones Indices LLC (“S&P DJI”) based on methodology proprietary to S&P DJI and BofA Merrill Lynch Research (“BofA Merrill Lynch”) (S&P DJI and BofA Merrill Lynch, collectively, the “Index Provider”) using a “modified market capitalization” methodology, which means that modifications may be made to the market capitalization weights of single stock concentrations in order to conform to the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code” or “IRC”). As of November 30, 2017, the Index was composed of 28 stocks. The Index is sponsored by the Index Provider and compiled by S&P DJI (the “Index Compilation Agent”). Neither entity is affiliated with the Fund or the Adviser. The Index Compilation Agent determines the composition of the Index and relative weightings of the securities in the Index based on the Index methodology. The Index Provider publishes information regarding the market value of the Index.
Risk [Heading]	rr_RiskHeading	<b>Principal Risks of Investing in the Fund </b>
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. When there are changes made to the component securities of the Index and the Fund in turn makes similar changes to its portfolio, any transaction costs and market exposure arising from such portfolio changes will be borne directly by the Fund and its shareholders. The Fund may recognize gains as a result of rebalancing or reconstituting its securities holdings to reflect changes in the securities included in the Index. The Fund also may be required to distribute any such gains to its shareholders to avoid adverse federal income tax consequences. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions. Utilities Sector Risk: The Fund's assets will be concentrated in the utilities sector, which means the Fund will be more affected by the performance of the utilities sector than a fund that is more diversified. Utility companies are affected by supply and demand, operating costs, government regulation, environmental factors, liabilities for environmental damage and general civil liabilities, and rate caps or rate changes. Although rate changes of a regulated utility usually fluctuate in approximate correlation with financing costs, due to political and regulatory factors rate changes ordinarily occur only following a delay after the changes in financing costs. This factor will tend to favorably affect a regulated utility company's earnings and dividends in times of decreasing costs, but conversely, will tend to adversely affect earnings and dividends when costs are rising. The value of regulated utility equity securities may tend to have an inverse relationship to the movement of interest rates. Certain utility companies have experienced full or partial deregulation in recent years. These utility companies are frequently more similar to industrial companies in that they are subject to greater competition and have been permitted by regulators to diversify outside of their original geographic regions and their traditional lines of business. These opportunities may permit certain utility companies to earn more than their traditional regulated rates of return. Some companies, however, may be forced to defend their core business and may be less profitable. In addition, natural disasters, terrorist attacks, government intervention or other factors may render a utility company's equipment unusable or obsolete and negatively impact profitability. Among the risks that may affect utility companies are the following: risks of increases in fuel and other operating costs; the high cost of borrowing to finance capital construction during inflationary periods; restrictions on operations and increased costs and delays associated with compliance with environmental and nuclear safety regulations; and the difficulties involved in obtaining natural gas for resale or fuel for generating electricity at reasonable prices. Other risks include those related to the construction and operation of nuclear power plants, the effects of energy conservation and the effects of regulatory changes. Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time. Non-Diversification Risk: As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds. Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies. Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with all investments, there are certain risks of investing in the Fund. Fund Shares will change in value, and you could lose money by investing in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	<blockquote><b>Non-Diversification Risk:</b> As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.</blockquote>
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<b>Fund Performance </b>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index. The S&P 500 Index is a well-known, broad-based securities market index that includes common stocks of approximately 500 companies from a number of sectors representing a significant portion of the market value of all stocks publicly traded in the United States. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available by calling 1-866-732-8673 or visiting our website at www.sectorspdrs.com.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The following bar chart and table provide an 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 returns for certain time periods compare with the average annual returns of the Index, and the S&P 500 Index.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	1-866-732-8673
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.sectorspdrs.com
Performance Past Does Not Indicate Future [Text]	rr_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 [Heading]	rr_BarChartHeading	<b>Annual Total Returns (years ended 12/31) </b>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Highest Quarterly Return: 15.47% (Q1, 2016) Lowest Quarterly Return: -18.01% (Q3, 2008)
Performance Table Heading	rr_PerformanceTableHeading	<b>Average Annual Total Returns (for periods ending 12/31/17) </b>
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	The after-tax returns presented in the table below are calculated using highest historical individual federal marginal income tax rates 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 will depend on your specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	The after-tax returns presented in the table below are calculated using highest historical 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 specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold Fund Shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. The returns after taxes can exceed the returns before taxes due to an assumed tax benefit for a shareholder from realizing a capital loss on a sale of Fund Shares.
The Utilities Select Sector SPDR Fund | The Utilities Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
Management fees	rr_ManagementFeesOverAssets	0.03%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.04%
Other expenses	rr_OtherExpensesOverAssets	0.06%
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.13%	[1]
Year 1	rr_ExpenseExampleYear01	$ 13
Year 3	rr_ExpenseExampleYear03	42
Year 5	rr_ExpenseExampleYear05	73
Year 10	rr_ExpenseExampleYear10	$ 166
2008	rr_AnnualReturn2008	(29.09%)
2009	rr_AnnualReturn2009	11.39%
2010	rr_AnnualReturn2010	5.27%
2011	rr_AnnualReturn2011	19.51%
2012	rr_AnnualReturn2012	1.10%
2013	rr_AnnualReturn2013	13.00%
2014	rr_AnnualReturn2014	28.59%
2015	rr_AnnualReturn2015	(4.86%)
2016	rr_AnnualReturn2016	16.00%
2017	rr_AnnualReturn2017	12.02%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest Quarterly Return:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Mar. 31, 2016
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	15.47%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest Quarterly Return:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Sep. 30, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(18.01%)
One Year	rr_AverageAnnualReturnYear01	12.02%
Five Years	rr_AverageAnnualReturnYear05	12.43%
Ten Years	rr_AverageAnnualReturnYear10	6.08%
The Utilities Select Sector SPDR Fund | Return After Taxes on Distributions | The Utilities Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	11.14%
Five Years	rr_AverageAnnualReturnYear05	11.47%
Ten Years	rr_AverageAnnualReturnYear10	5.29%
The Utilities Select Sector SPDR Fund | Return After Taxes on Distributions and Sale of Fund Shares | The Utilities Select Sector SPDR Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	7.51%
Five Years	rr_AverageAnnualReturnYear05	9.76%
Ten Years	rr_AverageAnnualReturnYear10	4.75%
The Utilities Select Sector SPDR Fund | The Utilities Select Sector Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	12.10%
Five Years	rr_AverageAnnualReturnYear05	12.64%
Ten Years	rr_AverageAnnualReturnYear10	6.29%
The Utilities Select Sector SPDR Fund | S&P 500 Index (Index returns reflect no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	21.83%
Five Years	rr_AverageAnnualReturnYear05	15.79%
Ten Years	rr_AverageAnnualReturnYear10	8.50%

[1] The Fund's “Total annual Fund operating expenses” have been restated to reflect a reduction in the Fund's “Distribution and service (12b-1) fees” and “Other expenses”.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	SELECT SECTOR SPDR TRUST
Prospectus Date	rr_ProspectusDate	Sep. 24, 2018
Document Creation Date	dei_DocumentCreationDate	Sep. 24, 2018