v3.26.1
Annual Fund Operating Expenses - Loomis Sayles Funds I - Classes Admin, Retail, Institutional, and N
Dec. 31, 2025
Loomis Sayles Income Fund  
Prospectus [Line Items]  
Fee Waiver or Reimbursement over Assets, Date of Termination April 30, 2027
Loomis Sayles Income Fund | Institutional  
Prospectus [Line Items]  
Management Fees (as a percentage of Assets) 0.56%
Distribution and Service (12b-1) Fees 0.00%
Other Expenses (as a percentage of Assets): 0.15%
Expenses (as a percentage of Assets) 0.71%
Fee Waiver or Reimbursement 0.07% [1]
Net Expenses (as a percentage of Assets) 0.64%
Loomis Sayles Income Fund | Retail  
Prospectus [Line Items]  
Management Fees (as a percentage of Assets) 0.56%
Distribution and Service (12b-1) Fees 0.25%
Other Expenses (as a percentage of Assets): 0.15%
Expenses (as a percentage of Assets) 0.96%
Fee Waiver or Reimbursement 0.07% [1]
Net Expenses (as a percentage of Assets) 0.89%
Loomis Sayles Income Fund | Admin  
Prospectus [Line Items]  
Management Fees (as a percentage of Assets) 0.56%
Distribution and Service (12b-1) Fees 0.25%
Other Expenses (as a percentage of Assets): 0.39% [2]
Expenses (as a percentage of Assets) 1.20%
Fee Waiver or Reimbursement 0.06% [1],[3]
Net Expenses (as a percentage of Assets) 1.14%
Loomis Sayles Income Fund | N  
Prospectus [Line Items]  
Management Fees (as a percentage of Assets) 0.56%
Distribution and Service (12b-1) Fees 0.00%
Other Expenses (as a percentage of Assets): 0.07%
Expenses (as a percentage of Assets) 0.63%
Fee Waiver or Reimbursement 0.04% [1]
Net Expenses (as a percentage of Assets) 0.59%
Loomis Sayles Investment Grade Fixed Income Fund  
Prospectus [Line Items]  
Fee Waiver or Reimbursement over Assets, Date of Termination April 30, 2027
Loomis Sayles Investment Grade Fixed Income Fund | Institutional  
Prospectus [Line Items]  
Management Fees (as a percentage of Assets) 0.40%
Distribution and Service (12b-1) Fees 0.00%
Other Expenses (as a percentage of Assets): 0.19%
Expenses (as a percentage of Assets) 0.59%
Fee Waiver or Reimbursement 0.06% [4]
Net Expenses (as a percentage of Assets) 0.53%
[1]
2 Loomis, Sayles & Company, L.P. (“Loomis Sayles” or the “Adviser”) has given a binding contractual undertaking to the Fund to limit the amount of the Fund’s total annual fund operating expenses to 0.64%, 0.89%, 1.14% and 0.59% of the Fund’s average daily net assets for Institutional Class shares, Retail Class shares, Admin Class shares and Class N shares, respectively, exclusive of acquired fund fees and expenses, brokerage expenses, interest expense, taxes, and organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through April 30, 2027 and may be terminated before then only with the consent of the Fund’s Board of Trustees. The Adviser will be permitted to recover, on a class by class basis, management fees waived and/or expenses reimbursed to the extent that expenses in later periods fall below both (1) the class’ applicable expense limitation at the time such amounts were waived/reimbursed and (2) the class’ current applicable expense limitation. The Fund will not be obligated to repay any such waived/reimbursed fees and expenses more than one year after the end of the fiscal year in which the fees or expenses were waived/reimbursed.
[2]
1 Other expenses include an administrative services fee of 0.24% for Admin Class shares.
[3]
3 In order to ensure that the total annual fund operating expenses after fee waiver and/or expense reimbursement do not exceed the amounts disclosed in the table, the Adviser may voluntarily waive additional advisory fees and/or other expenses. This may result in Admin Class shareholders realizing a total annual fund operating expense after fee waiver and/or expense reimbursement lower than 1.14% of the Fund’s average daily net assets. This additional waiver may be terminated at any time.
[4]
1 Loomis, Sayles & Company, L.P. (“Loomis Sayles” or the “Adviser”) has given a binding contractual undertaking to the Fund to limit the amount of the Fund’s total annual fund operating expenses to 0.53% of the Fund’s average daily net assets, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through April 30, 2027 and may be terminated before then only with the consent of the Fund’s Board of Trustees. The Adviser will be permitted to recover management fees waived and/or expenses reimbursed to the extent that expenses in later periods fall below both (1) the expense limitation at the time such amounts were waived/reimbursed and (2) the Fund’s current applicable expense limitation. The Fund will not be obligated to repay any such waived/reimbursed fees and expenses more than one year after the end of the fiscal year in which the fees or expenses were waived/reimbursed.