| **Shareholder Fees - FidelitySAIInternationalSMACompletionFund-PRO**                           | Dec. 30, 2023 USD ($) |
|------------------------------------------------------------------------------------------------|-----------------------|
| FidelitySAIInternationalSMACompletionFund-PRO | Fidelity SAI International SMA Completion Fund |                  |
| **Shareholder Fees:**                                                                          |                  |
| (fees paid directly from your investment)                                                      | none                  |

| X                                                                                                                                                                                                                                                                                                                                                                    |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Other Expenses
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 10
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| X                                                                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - References
No definition available.
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| X                                                                                                                                                                                   |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                |
|----------------------------------------------------------------------------------------------------------------------------------|
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