XML 11 R2.htm IDEA: XBRL DOCUMENT v2.4.0.6
Label Element Value
Risk/Return: rr_RiskReturnAbstract  
Document Type dei_DocumentType Other
Document Period End Date dei_DocumentPeriodEndDate Jan. 04, 2012
Registrant Name dei_EntityRegistrantName FIDELITY SALEM STREET TRUST
Central Index Key dei_EntityCentralIndexKey 0000035315
Amendment Flag dei_AmendmentFlag false
Document Creation Date dei_DocumentCreationDate Jan. 04, 2012
Document Effective Date dei_DocumentEffectiveDate Jan. 04, 2012
Prospectus Date rr_ProspectusDate Oct. 29, 2011
Spartan U.S. Bond Index Fund | Inv Adv
 
Risk/Return: rr_RiskReturnAbstract  
Supplement [Text Block] fsst35315_SupplementTextBlock
Supplement to the
Spartan® U.S. Bond Index Fund (formerly Fidelity® U.S. Bond Index Fund)
Investor Class and Fidelity Advantage® Class
October 29, 2011
Prospectus
Effective February 1, 2012, the following information replaces the similar information under the heading "Fee Table" in the "Fund Summary" section on page 3.
Annual class operating expenses
(expenses that you pay each year as a % of the value of your investment)
 
  Investor
Class
 
  Fidelity
Advantage
Class
 
Management fee
0.05%   0.05%
Distribution and/or Service (12b-1) fees
None   None
Other expenses
0.17%   0.12%
Total annual operating expenses
0.22%A   0.17%
Fee waiver and/or expense reimbursementB
    0.06%
Total annual operating expenses after fee waiver and/or expense reimbursement
    0.11%
A Based on historical expenses, adjusted to reflect current fees.
B Fidelity Management & Research Company (FMR) has contractually agreed to reimburse Fidelity Advantage Class of the fund to the extent that total operating expenses (excluding interest, taxes, certain securities lending costs, brokerage commissions, extraordinary expenses, and acquired fund fees and expenses, if any), as a percentage of its average net assets, exceed 0.11%. This arrangement will remain in effect through October 31, 2013.
Effective February 1, 2012, the following information replaces the similar information under the heading "Fee Table" in the "Fund Summary" section on page 4.
 
  Investor
Class
 
  Fidelity
Advantage
Class
 
1 year
$23   $11
3 years
$71   $44
5 years
$124   $85
10 years
$280   $206