v3.26.1
Shareholder Report
 6 Months Ended
Apr. 30, 2026
USD ($)
$ / shares
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name Putnam Global Income Trust
Entity Central Index Key 0000794614
Entity Investment Company Type N-1A
Document Period End Date Apr. 30, 2026
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Class A  
Shareholder Report [Line Items]  
Fund Name Putnam Global Income Trust
Class Name Class A
Trading Symbol PGGIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about Putnam Global Income Trust for the period November 1, 2025, to April 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) 225-1581.
Additional Information Phone Number (800) 225-1581
Additional Information Website https://www.franklintempleton.com/regulatory-fund-documents
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*,†
Class A
$44
0.88%
[1],[2]
Expenses Paid, Amount $ 44
Expense Ratio, Percent 0.88%
Net Assets $ 215,414,043
Holdings Count | $ / shares 715
Investment Company Portfolio Turnover 138.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of April 30, 2026)
Total Net Assets
$215,414,043
Total Number of Portfolio Holdings (excludes derivatives, except purchased options, if any)
715
Portfolio Turnover Rate
138%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (as of April 30, 2026)
Portfolio Composition* (% of Total Investments)
image
 [3]
Updated Prospectus Web Address https://www.franklintempleton.com/regulatory-fund-documents
Class C  
Shareholder Report [Line Items]  
Fund Name Putnam Global Income Trust
Class Name Class C
Trading Symbol PGGLX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about Putnam Global Income Trust for the period November 1, 2025, to April 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) 225-1581.
Additional Information Phone Number (800) 225-1581
Additional Information Website https://www.franklintempleton.com/regulatory-fund-documents
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*,†
Class C
$81
1.63%
[4],[5]
Expenses Paid, Amount $ 81
Expense Ratio, Percent 1.63%
Net Assets $ 215,414,043
Holdings Count | $ / shares 715
Investment Company Portfolio Turnover 138.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of April 30, 2026)
Total Net Assets
$215,414,043
Total Number of Portfolio Holdings (excludes derivatives, except purchased options, if any)
715
Portfolio Turnover Rate
138%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (as of April 30, 2026)
Portfolio Composition* (% of Total Investments)
image
 [6]
Updated Prospectus Web Address https://www.franklintempleton.com/regulatory-fund-documents
Class R  
Shareholder Report [Line Items]  
Fund Name Putnam Global Income Trust
Class Name Class R
Trading Symbol PGBRX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about Putnam Global Income Trust for the period November 1, 2025, to April 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) 225-1581.
Additional Information Phone Number (800) 225-1581
Additional Information Website https://www.franklintempleton.com/regulatory-fund-documents
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*,†
Class R
$56
1.13%
[7],[8]
Expenses Paid, Amount $ 56
Expense Ratio, Percent 1.13%
Net Assets $ 215,414,043
Holdings Count | $ / shares 715
Investment Company Portfolio Turnover 138.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of April 30, 2026)
Total Net Assets
$215,414,043
Total Number of Portfolio Holdings (excludes derivatives, except purchased options, if any)
715
Portfolio Turnover Rate
138%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (as of April 30, 2026)
Portfolio Composition* (% of Total Investments)
image
 [9]
Updated Prospectus Web Address https://www.franklintempleton.com/regulatory-fund-documents
Class R5  
Shareholder Report [Line Items]  
Fund Name Putnam Global Income Trust
Class Name Class R5
Trading Symbol PGGDX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about Putnam Global Income Trust for the period November 1, 2025, to April 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) 225-1581.
Additional Information Phone Number (800) 225-1581
Additional Information Website https://www.franklintempleton.com/regulatory-fund-documents
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*,†
Class R5
$26
0.53%
[10],[11]
Expenses Paid, Amount $ 26
Expense Ratio, Percent 0.53%
Net Assets $ 215,414,043
Holdings Count | $ / shares 715
Investment Company Portfolio Turnover 138.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of April 30, 2026)
Total Net Assets
$215,414,043
Total Number of Portfolio Holdings (excludes derivatives, except purchased options, if any)
715
Portfolio Turnover Rate
138%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (as of April 30, 2026)
Portfolio Composition* (% of Total Investments)
image
 [12]
Updated Prospectus Web Address https://www.franklintempleton.com/regulatory-fund-documents
Class R6  
Shareholder Report [Line Items]  
Fund Name Putnam Global Income Trust
Class Name Class R6
Trading Symbol PGGEX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about Putnam Global Income Trust for the period November 1, 2025, to April 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) 225-1581.
Additional Information Phone Number (800) 225-1581
Additional Information Website https://www.franklintempleton.com/regulatory-fund-documents
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*,†
Class R6
$24
0.48%
[13],[14]
Expenses Paid, Amount $ 24
Expense Ratio, Percent 0.48%
Net Assets $ 215,414,043
Holdings Count | $ / shares 715
Investment Company Portfolio Turnover 138.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of April 30, 2026)
Total Net Assets
$215,414,043
Total Number of Portfolio Holdings (excludes derivatives, except purchased options, if any)
715
Portfolio Turnover Rate
138%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (as of April 30, 2026)
Portfolio Composition* (% of Total Investments)
image
 [15]
Updated Prospectus Web Address https://www.franklintempleton.com/regulatory-fund-documents
Class Y  
Shareholder Report [Line Items]  
Fund Name Putnam Global Income Trust
Class Name Class Y
Trading Symbol PGGYX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about Putnam Global Income Trust for the period November 1, 2025, to April 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) 225-1581.
Additional Information Phone Number (800) 225-1581
Additional Information Website https://www.franklintempleton.com/regulatory-fund-documents
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*,†
Class Y
$31
0.63%
[16],[17]
Expenses Paid, Amount $ 31
Expense Ratio, Percent 0.63%
Net Assets $ 215,414,043
Holdings Count | $ / shares 715
Investment Company Portfolio Turnover 138.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of April 30, 2026)
Total Net Assets
$215,414,043
Total Number of Portfolio Holdings (excludes derivatives, except purchased options, if any)
715
Portfolio Turnover Rate
138%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (as of April 30, 2026)
Portfolio Composition* (% of Total Investments)
image
 [18]
Updated Prospectus Web Address https://www.franklintempleton.com/regulatory-fund-documents
[1]
* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.
[2]
† Annualized.
[3]
* Does not include derivatives, except purchased options, if any.  
[4]
* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.
[5]
† Annualized.
[6]
* Does not include derivatives, except purchased options, if any.  
[7]
* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.
[8]
† Annualized.
[9]
* Does not include derivatives, except purchased options, if any.  
[10]
* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.
[11]
† Annualized.
[12]
* Does not include derivatives, except purchased options, if any.  
[13]
* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.
[14]
† Annualized.
[15]
* Does not include derivatives, except purchased options, if any.  
[16]
* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.
[17]
† Annualized.
[18]
* Does not include derivatives, except purchased options, if any.