v3.25.4
Shareholder Report
12 Months Ended
Dec. 31, 2025
USD ($)
Holding
Shareholder Report [Line Items]  
Document Type N-CSR
Amendment Flag false
Registrant Name BNY Mellon Investment Funds I
Entity Central Index Key 0000799295
Entity Investment Company Type N-1A
Document Period End Date Dec. 31, 2025
C000130461 [Member]  
Shareholder Report [Line Items]  
Fund Name BNY Mellon Global Fixed Income Fund
Class Name Class Y
Trading Symbol DSDYX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about BNY Mellon Global Fixed Income Fund (the “Fund”) for the period of January 1, 2025 to December 31, 2025.
Shareholder Report Annual or Semi-Annual annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at bny.com/investments/literaturecenter. You can also request this information by calling 1-800-373-9387 (inside the U.S. only) or by sending an e-mail request to info@bny.com.
Additional Information Phone Number 1-800-373-9387
Additional Information Email info@bny.com
Additional Information Website bny.com/investments/literaturecenter
Expenses [Text Block]
What were the Fund’s costs for the last year ?
(based on a hypothetical $10,000 investment)
Share Class Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment
Class Y $50 0.49%
Expenses Paid, Amount $ 50
Expense Ratio, Percent 0.49%
Factors Affecting Performance [Text Block]
How did the Fund perform last year ?
  • For the 12-month period ended December 31, 2025, the Fund’s Class Y shares returned 4.69%.
  • In comparison, the Bloomberg Global Aggregate Index (Hedged) (the “Index”) returned 4.86% for the same period.
What affected the Fund’s performance?
  • Global fixed income markets performed well, supported by tighter spreads and high running yields. Performance of risk-free rates was mixed, with most major yield curves steepening.
  • The Fund’s relative performance benefited primarily from active positioning for a steeper U.S. yield curve. Relative value in the inflation space and security selection were secondary drivers of performance.
  • Underweight exposure to credit beta detracted from relative returns, particularly in the second and third quarters. Japanese yield curve flatteners and active foreign-exchange positioning were secondary detractors.
Performance Past Does Not Indicate Future [Text] The Fund’s past performance is not a good predictor of the Fund’s future performance.
Line Graph [Table Text Block]
How did the Fund perform over the past 10 years?
The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Cumulative Performance from January 1 , 2015 through December 31, 2025
Initial Investment of $1,000,000
Fund Performance - Growth of 10K Chart
The above graph compares a hypothetical $1,000,000 investment in the Fund’s Class Y shares to a hypothetical investment of $1,000,000 made in the Bloomberg Global Aggregate Index (Hedged) on 12/31/2015. The performance shown takes into account applicable fees and expenses of the Fund, including management fees and other expenses. The Fund’s performance also assumes the reinvestment of dividends and capital gains. Unlike the Fund, the Index is not subject to charges, fees and other expenses. Investors cannot invest directly in any index.
Average Annual Return [Table Text Block]
AVERAGE ANNUAL TOTAL RETURNS (AS OF 12/31/25 )
Share Class 1YR 5YR 10YR
Class Y 4.69% 1.17% 2.81%
Bloomberg Global Aggregate Index (Hedged) 4.86% 0.34% 2.39%
No Deduction of Taxes [Text Block] The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Updated Performance Information Location [Text Block] For more current information visit bny.com/investments/literaturecenter . 
Net Assets $ 4,494,000,000
Holdings Count | Holding 454
Advisory Fees Paid, Amount $ 14,010,450
Investment Company Portfolio Turnover 85.94%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (AS OF 12/31/25 )

Fund Size (Millions)

Number of Holdings
Total Advisory Fee Paid During
Period

Annual Portfolio Turnover
$4,494 454 $14,010,450 85.94%
Holdings [Text Block]
Portfolio Holdings (as of 12/31/25 )
Country Allocation (Based on Net Assets)
Graphical Representation - Top N Holdings Chart
Allocation of Holdings (Based on Net Assets)
Graphical Representation - Allocation 1 Chart
* Amount represents less than .1%.
C000031763 [Member]  
Shareholder Report [Line Items]  
Fund Name BNY Mellon Global Fixed Income Fund
Class Name Class I
Trading Symbol SDGIX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about BNY Mellon Global Fixed Income Fund (the “Fund”) for the period of January 1, 2025 to December 31, 2025.
Shareholder Report Annual or Semi-Annual annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at bny.com/investments/literaturecenter. You can also request this information by calling 1-800-373-9387 (inside the U.S. only) or by sending an e-mail request to info@bny.com.
Additional Information Phone Number 1-800-373-9387
Additional Information Email info@bny.com
Additional Information Website bny.com/investments/literaturecenter
Expenses [Text Block]
What were the Fund’s costs for the last year ?
(based on a hypothetical $10,000 investment)
Share Class Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment
Class I $55 0.54%
Expenses Paid, Amount $ 55
Expense Ratio, Percent 0.54%
Factors Affecting Performance [Text Block]
How did the Fund perform last year ?
  • For the 12-month period ended December 31, 2025, the Fund’s Class I shares returned 4.63%.
  • In comparison, the Bloomberg Global Aggregate Index (Hedged) (the “Index”) returned 4.86% for the same period.
What affected the Fund’s performance?
  • Global fixed income markets performed well, supported by tighter spreads and high running yields. Performance of risk-free rates was mixed, with most major yield curves steepening.
  • The Fund’s relative performance benefited primarily from active positioning for a steeper U.S. yield curve. Relative value in the inflation space and security selection were secondary drivers of performance.
  • Underweight exposure to credit beta detracted from relative returns, particularly in the second and third quarters. Japanese yield curve flatteners and active foreign-exchange positioning were secondary detractors.
Performance Past Does Not Indicate Future [Text] The Fund’s past performance is not a good predictor of the Fund’s future performance.
Line Graph [Table Text Block]
How did the Fund perform over the past 10 years?
The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Cumulative Performance from January 1 , 2015 through December 31, 2025
Initial Investment of $10,000
Fund Performance - Growth of 10K Chart
The above graph compares a hypothetical $10,000 investment in the Fund’s Class I shares to a hypothetical investment of $10,000 made in the Bloomberg Global Aggregate Index (Hedged) on 12/31/2015. The performance shown takes into account applicable fees and expenses of the Fund, including management fees and other expenses. The Fund’s performance also assumes the reinvestment of dividends and capital gains. Unlike the Fund, the Index is not subject to charges, fees and other expenses. Investors cannot invest directly in any index.
Average Annual Return [Table Text Block]
AVERAGE ANNUAL TOTAL RETURNS (AS OF 12/31/25 )
Share Class 1YR 5YR 10YR
Class I 4.63% 1.10% 2.75%
Bloomberg Global Aggregate Index (Hedged) 4.86% 0.34% 2.39%
No Deduction of Taxes [Text Block] The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Updated Performance Information Location [Text Block] For more current information visit bny.com/investments/literaturecenter . 
Net Assets $ 4,494,000,000
Holdings Count | Holding 454
Advisory Fees Paid, Amount $ 14,010,450
Investment Company Portfolio Turnover 85.94%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (AS OF 12/31/25 )

Fund Size (Millions)

Number of Holdings
Total Advisory Fee Paid During
Period

Annual Portfolio Turnover
$4,494 454 $14,010,450 85.94%
Holdings [Text Block]
Portfolio Holdings (as of 12/31/25 )
Country Allocation (Based on Net Assets)
Graphical Representation - Top N Holdings Chart
Allocation of Holdings (Based on Net Assets)
Graphical Representation - Allocation 1 Chart
* Amount represents less than .1%.
C000081695 [Member]  
Shareholder Report [Line Items]  
Fund Name BNY Mellon Global Fixed Income Fund
Class Name Class C
Trading Symbol DHGCX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about BNY Mellon Global Fixed Income Fund (the “Fund”) for the period of January 1, 2025 to December 31, 2025.
Shareholder Report Annual or Semi-Annual annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at bny.com/investments/literaturecenter. You can also request this information by calling 1-800-373-9387 (inside the U.S. only) or by sending an e-mail request to info@bny.com.
Additional Information Phone Number 1-800-373-9387
Additional Information Email info@bny.com
Additional Information Website bny.com/investments/literaturecenter
Expenses [Text Block]
What were the Fund’s costs for the last year ?
(based on a hypothetical $10,000 investment)
Share Class Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment
Class C $158 1.55%
Expenses Paid, Amount $ 158
Expense Ratio, Percent 1.55%
Factors Affecting Performance [Text Block]
How did the Fund perform last year ?
  • For the 12-month period ended December 31, 2025, the Fund’s Class C shares returned 3.54%.
  • In comparison, the Bloomberg Global Aggregate Index (Hedged) (the “Index”) returned 4.86% for the same period.
What affected the Fund’s performance?
  • Global fixed income markets performed well, supported by tighter spreads and high running yields. Performance of risk-free rates was mixed, with most major yield curves steepening.
  • The Fund’s relative performance benefited primarily from active positioning for a steeper U.S. yield curve. Relative value in the inflation space and security selection were secondary drivers of performance.
  • Underweight exposure to credit beta detracted from relative returns, particularly in the second and third quarters. Japanese yield curve flatteners and active foreign-exchange positioning were secondary detractors.
Performance Past Does Not Indicate Future [Text] The Fund’s past performance is not a good predictor of the Fund’s future performance.
Line Graph [Table Text Block]
How did the Fund perform over the past 10 years?
The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Cumulative Performance from January 1 , 2015 through December 31, 2025
Initial Investment of $10,000
Fund Performance - Growth of 10K Chart
The above graph compares a hypothetical $10,000 investment in the Fund’s Class C shares to a hypothetical investment of $10,000 made in the Bloomberg Global Aggregate Index (Hedged) on 12/31/2015. The performance shown takes into account the maximum deferred sales charge on Class C shares and applicable fees and expenses of the Fund, including management fees, 12b-1 fees and other expenses. The Fund’s performance also assumes the reinvestment of dividends and capital gains. Unlike the Fund, the Index is not subject to charges, fees and other expenses. Investors cannot invest directly in any index.
Average Annual Return [Table Text Block]
AVERAGE ANNUAL TOTAL RETURNS (AS OF 12/31/25 )
Class C Shares 1YR 5YR 10YR
with Maximum Deferred Sales Charge - 1.00% 2.54%
*
0.05% 1.68%
without Deferred Sales Charge 3.54% 0.05% 1.68%
Bloomberg Global Aggregate Index (Hedged) 4.86% 0.34% 2.39%
*
The maximum contingent deferred sales charge for Class C shares is 1.00% for shares redeemed within one year of the date purchased.
No Deduction of Taxes [Text Block] The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Updated Performance Information Location [Text Block] For more current information visit bny.com/investments/literaturecenter . 
Net Assets $ 4,494,000,000
Holdings Count | Holding 454
Advisory Fees Paid, Amount $ 14,010,450
Investment Company Portfolio Turnover 85.94%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (AS OF 12/31/25 )

Fund Size (Millions)

Number of Holdings
Total Advisory Fee Paid During
Period

Annual Portfolio Turnover
$4,494 454 $14,010,450 85.94%
Holdings [Text Block]
Portfolio Holdings (as of 12/31/25 )
Country Allocation (Based on Net Assets)
Graphical Representation - Top N Holdings Chart
Allocation of Holdings (Based on Net Assets)
Graphical Representation - Allocation 1 Chart
* Amount represents less than .1%.
C000081694 [Member]  
Shareholder Report [Line Items]  
Fund Name BNY Mellon Global Fixed Income Fund
Class Name Class A
Trading Symbol DHGAX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about BNY Mellon Global Fixed Income Fund (the “Fund”) for the period of January 1, 2025 to December 31, 2025.
Shareholder Report Annual or Semi-Annual annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at bny.com/investments/literaturecenter. You can also request this information by calling 1-800-373-9387 (inside the U.S. only) or by sending an e-mail request to info@bny.com.
Additional Information Phone Number 1-800-373-9387
Additional Information Email info@bny.com
Additional Information Website bny.com/investments/literaturecenter
Expenses [Text Block]
What were the Fund’s costs for the last year ?
(based on a hypothetical $10,000 investment)
Share Class Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment
Class A $88 0.86%
Expenses Paid, Amount $ 88
Expense Ratio, Percent 0.86%
Factors Affecting Performance [Text Block]
How did the Fund perform last year ?
  • For the 12-month period ended December 31, 2025, the Fund’s Class A shares returned 4.31%.
  • In comparison, the Bloomberg Global Aggregate Index (Hedged) (the “Index”) returned 4.86% for the same period.
What affected the Fund’s performance?
  • Global fixed income markets performed well, supported by tighter spreads and high running yields. Performance of risk-free rates was mixed, with most major yield curves steepening.
  • The Fund’s relative performance benefited primarily from active positioning for a steeper U.S. yield curve. Relative value in the inflation space and security selection were secondary drivers of performance.
  • Underweight exposure to credit beta detracted from relative returns, particularly in the second and third quarters. Japanese yield curve flatteners and active foreign-exchange positioning were secondary detractors.
Performance Past Does Not Indicate Future [Text] The Fund’s past performance is not a good predictor of the Fund’s future performance.
Line Graph [Table Text Block]
How did the Fund perform over the past 10 years?
The Fund’s past performance is not a good predictor of the Fund’s future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Cumulative Performance from January 1 , 2015 through December 31, 2025
Initial Investment of $10,000
Fund Performance - Growth of 10K Chart
The above graph compares a hypothetical $10,000 investment in the Fund’s Class A shares to a hypothetical investment of $10,000 made in the Bloomberg Global Aggregate Index (Hedged) on 12/31/2015. The performance shown takes into account the maximum initial sales charge on Class A shares and applicable fees and expenses of the Fund, including management fees and other expenses. The Fund’s performance also assumes the reinvestment of dividends and capital gains. Unlike the Fund, the Index is not subject to charges, fees and other expenses. Investors cannot invest directly in any index.
Average Annual Return [Table Text Block]
AVERAGE ANNUAL TOTAL RETURNS (AS OF 12/31/25 )
Class A Shares 1YR 5YR 10YR
with Maximum Sales Charge - 4.50% -0.40% -0.14% 1.97%
without Sales Charge 4.31% 0.79% 2.44%
Bloomberg Global Aggregate Index (Hedged) 4.86% 0.34% 2.39%
No Deduction of Taxes [Text Block] The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Updated Performance Information Location [Text Block] For more current information visit bny.com/investments/literaturecenter . 
Net Assets $ 4,494,000,000
Holdings Count | Holding 454
Advisory Fees Paid, Amount $ 14,010,450
Investment Company Portfolio Turnover 85.94%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (AS OF 12/31/25 )

Fund Size (Millions)

Number of Holdings
Total Advisory Fee Paid During
Period

Annual Portfolio Turnover
$4,494 454 $14,010,450 85.94%
Holdings [Text Block]
Portfolio Holdings (as of 12/31/25 )
Country Allocation (Based on Net Assets)
Graphical Representation - Top N Holdings Chart
Allocation of Holdings (Based on Net Assets)
Graphical Representation - Allocation 1 Chart
* Amount represents less than .1%.