| Form N-CSR Cover | 12 Months Ended |
| Jul. 31, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | PUTNAM TAX FREE INCOME TRUST |
| Entity Central Index Key | 0000771951 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Jul. 31, 2024 |
| Shareholder Report | 12 Months Ended | |
| Jul. 31, 2024 USD ($) $ / shares | ||
| Shareholder Report [Line Items] | ||
| Document Type | N-CSR | |
| Amendment Flag | false | |
| Registrant Name | PUTNAM TAX FREE INCOME TRUST | |
| Entity Central Index Key | 0000771951 | |
| Entity Investment Company Type | N-1A | |
| Document Period End Date | Jul. 31, 2024 | |
| Class A | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Putnam Tax-Free High Yield Fund | |
| Class Name | Class A | |
| Trading Symbol | PTHAX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about Putnam Tax-Free High Yield Fund for the period August 1, 2023, to July 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| 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 . | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the reporting period. | |
| 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 YEAR? (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 $100 0.96% | |
| Expenses Paid, Amount | $ 100 | |
| Expense Ratio, Percent | 0.96% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR AND WHAT AFFECTED ITS PERFORMANCE? For the twelve months ended July 31, 2024, Class A shares of Putnam Tax-Free High Yield Fund returned 8.60%. The Fund compares its performance to the Bloomberg Municipal Bond Index, which returned 3.74% for the same period. PERFORMANCE HIGHLIGHTS Top contributors to performance: ↑ Long duration position as municipal bonds (munis) moved in sync with falling U.S. Treasury yields, specifically during the end of 2023 ↑ Focus on bonds at the longer end of the muni bond curve as longer-term munis outperformed their intermediate and short-term cohorts ↑ Security selection within non-rated bonds as spreads tightened across this space ↑ Bias towards the lower tiers of the investment-grade universe (bonds rated BBB) and the highest-rated portions of the high-yield universe as spreads tightened in these cohorts ↑ Security selection across a wide range of sectors, including nursing homes, hospitals, airports, and charter schools Top detractors from performance: ↓ Underweight exposure to bonds in Puerto Rico ↓ Security selection across private higher education and multi-family housing Use of derivatives and the impact on performance: The Fund utilized U.S. Treasury futures for yield curve positioning, which had a positive impact on performance. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not necessarily an indication of how the Fund will perform in the future. | |
| Line Graph [Table Text Block] | ||
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS (%) Period Ended July 31, 2024 1 Year 5 Year 10 Year Class A 8.60 2.10 3.60 Class A (with sales charge) 4.25 1.27 3.18 Bloomberg Municipal Bond Index 3.74 1.18 2.47 | |
| 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 current month-end performance, please call Franklin Templeton at (800) 225-1581 or visit https://www.franklintempleton.com/investments/options/mutual-funds . Important data provider notices and terms available at www.franklintempletondatasources.com. | |
| Net Assets | $ 688,773,603 | |
| Holdings Count | $ / shares | 409 | [1] |
| Advisory Fees Paid, Amount | $ 3,098,608 | |
| Investment Company Portfolio Turnover | 25% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (as of July 31, 2024) Total Net Assets $688,773,603 Total Number of Portfolio Holdings * 409 Total Management Fee Paid $3,098,608 Portfolio Turnover Rate 25% | [1] |
| Holdings [Text Block] | [2] | |
| Material Fund Change [Text Block] | HOW HAS THE FUND CHANGED? On May 31, 2023, Franklin Resources, Inc. (“Franklin Resources”) and Great-West Lifeco Inc., the parent company of Putnam U.S. Holdings I, LLC (“Putnam Holdings”), announced that they had entered into a definitive agreement for a subsidiary of Franklin Resources to acquire Putnam Holdings in a stock and cash transaction (the “Transaction”). The Transaction was completed on January 1, 2024. As part of the Transaction, your Fund’s then-current investment advisor, Putnam Investment Management, LLC (“Putnam Management”), a wholly-owned subsidiary of Putnam Holdings, and your Fund’s sub-advisor, Putnam Investments Limited (“PIL”), an indirect, wholly-owned subsidiary of Putnam Holdings, became indirect, wholly-owned subsidiaries of Franklin Resources. In connection with the Transaction, shareholders of your Fund approved a new management contract with Putnam Management and a new sub-advisory contract with PIL. The new contracts are identical to the previous contracts, except for the effective dates, initial terms, updates to fund names as necessary to reflect previous name changes, and certain non-substantive changes. Effective July 15, 2024, Putnam Management transferred its management contract for your Fund to Franklin Advisers, Inc. (“Franklin Advisers”), and Franklin Advisers replaced Putnam Management as the investment advisor to your Fund. In connection with the transfer, your Fund’s portfolio managers, along with supporting research analysts and certain other investment staff of Putnam Management, also became employees of Franklin Advisers. Putnam Management also transferred to Franklin Advisers its sub-management agreement with PIL in respect of your Fund. Franklin Advisers is an indirect, wholly-owned subsidiary of Franklin Resources. In addition, effective July 15, 2024, Franklin Advisers retained Putnam Management as a sub-advisor to your Fund pursuant to a new subadvisory agreement. This is a summary of certain changes to the Fund since August 1, 2023. For more complete information, you may review the Fund’s current prospectus and any applicable supplements at https://www.franklintempleton.com/regulatory-fund-documents or upon request at (800) 225-1581 or funddocuments putnam.com . | |
| Updated Prospectus Phone Number | (800) 225-1581 | |
| Updated Prospectus Email Address | funddocuments@putnam.com | |
| Updated Prospectus Web Address | https://www.franklintempleton.com/regulatory-fund-documents | |
| Class B | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Putnam Tax-Free High Yield Fund | |
| Class Name | Class B | |
| Trading Symbol | PTHYX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about Putnam Tax-Free High Yield Fund for the period August 1, 2023, to July 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| 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 . | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the reporting period. | |
| 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 YEAR? (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 B $162 1.56% | |
| Expenses Paid, Amount | $ 162 | |
| Expense Ratio, Percent | 1.56% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR AND WHAT AFFECTED ITS PERFORMANCE? For the twelve months ended July 31, 2024, Class B shares of Putnam Tax-Free High Yield Fund returned 7.93%. The Fund compares its performance to the Bloomberg Municipal Bond Index, which returned 3.74% for the same period. PERFORMANCE HIGHLIGHTS Top contributors to performance: ↑ Long duration position as municipal bonds (munis) moved in sync with falling U.S. Treasury yields, specifically during the end of 2023 ↑ Focus on bonds at the longer end of the muni bond curve as longer-term munis outperformed their intermediate and short-term cohorts ↑ Security selection within non-rated bonds as spreads tightened across this space ↑ Bias towards the lower tiers of the investment-grade universe (bonds rated BBB) and the highest-rated portions of the high-yield universe as spreads tightened in these cohorts ↑ Security selection across a wide range of sectors, including nursing homes, hospitals, airports, and charter schools Top detractors from performance: ↓ Underweight exposure to bonds in Puerto Rico ↓ Security selection across private higher education and multi-family housing Use of derivatives and the impact on performance: The Fund utilized U.S. Treasury futures for yield curve positioning, which had a positive impact on performance. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not necessarily an indication of how the Fund will perform in the future. | |
| Line Graph [Table Text Block] | ||
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS (%) Period Ended July 31, 2024 1 Year 5 Year 10 Year Class B 7.93 1.48 3.10 Class B (with sales charge) 2.93 1.14 3.10 Bloomberg Municipal Bond Index 3.74 1.18 2.47 | |
| 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 current month-end performance, please call Franklin Templeton at (800) 225-1581 or visit https://www.franklintempleton.com/investments/options/mutual-funds . Important data provider notices and terms available at www.franklintempletondatasources.com. | |
| Net Assets | $ 688,773,603 | |
| Holdings Count | $ / shares | 409 | [3] |
| Advisory Fees Paid, Amount | $ 3,098,608 | |
| Investment Company Portfolio Turnover | 25% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (as of July 31, 2024) Total Net Assets $688,773,603 Total Number of Portfolio Holdings * 409 Total Management Fee Paid $3,098,608 Portfolio Turnover Rate 25% | [3] |
| Holdings [Text Block] | [4] | |
| Material Fund Change [Text Block] | HOW HAS THE FUND CHANGED? On May 31, 2023, Franklin Resources, Inc. (“Franklin Resources”) and Great-West Lifeco Inc., the parent company of Putnam U.S. Holdings I, LLC (“Putnam Holdings”), announced that they had entered into a definitive agreement for a subsidiary of Franklin Resources to acquire Putnam Holdings in a stock and cash transaction (the “Transaction”). The Transaction was completed on January 1, 2024. As part of the Transaction, your Fund’s then-current investment advisor, Putnam Investment Management, LLC (“Putnam Management”), a wholly-owned subsidiary of Putnam Holdings, and your Fund’s sub-advisor, Putnam Investments Limited (“PIL”), an indirect, wholly-owned subsidiary of Putnam Holdings, became indirect, wholly-owned subsidiaries of Franklin Resources. In connection with the Transaction, shareholders of your Fund approved a new management contract with Putnam Management and a new sub-advisory contract with PIL. The new contracts are identical to the previous contracts, except for the effective dates, initial terms, updates to fund names as necessary to reflect previous name changes, and certain non-substantive changes. Effective July 15, 2024, Putnam Management transferred its management contract for your Fund to Franklin Advisers, Inc. (“Franklin Advisers”), and Franklin Advisers replaced Putnam Management as the investment advisor to your Fund. In connection with the transfer, your Fund’s portfolio managers, along with supporting research analysts and certain other investment staff of Putnam Management, also became employees of Franklin Advisers. Putnam Management also transferred to Franklin Advisers its sub-management agreement with PIL in respect of your Fund. Franklin Advisers is an indirect, wholly-owned subsidiary of Franklin Resources. In addition, effective July 15, 2024, Franklin Advisers retained Putnam Management as a sub-advisor to your Fund pursuant to a new subadvisory agreement. Effective September 5, 2024 (the “Conversion Date”), class B shares of the fund acquired prior to the Conversion Date will convert automatically to class A shares. This is a summary of certain changes to the Fund since August 1, 2023. For more complete information, you may review the Fund’s current prospectus and any applicable supplements at https://www.franklintempleton.com/regulatory-fund-documents or upon request at (800) 225-1581 or funddocuments putnam.com . | |
| Updated Prospectus Phone Number | (800) 225-1581 | |
| Updated Prospectus Email Address | funddocuments@putnam.com | |
| Updated Prospectus Web Address | https://www.franklintempleton.com/regulatory-fund-documents | |
| Class C | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Putnam Tax-Free High Yield Fund | |
| Class Name | Class C | |
| Trading Symbol | PTCCX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about Putnam Tax-Free High Yield Fund for the period August 1, 2023, to July 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| 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 . | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the reporting period. | |
| 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 YEAR? (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 $178 1.71% | |
| Expenses Paid, Amount | $ 178 | |
| Expense Ratio, Percent | 1.71% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR AND WHAT AFFECTED ITS PERFORMANCE? For the twelve months ended July 31, 2024, Class C shares of Putnam Tax-Free High Yield Fund returned 7.87%. The Fund compares its performance to the Bloomberg Municipal Bond Index, which returned 3.74% for the same period. PERFORMANCE HIGHLIGHTS Top contributors to performance: ↑ Long duration position as municipal bonds (munis) moved in sync with falling U.S. Treasury yields, specifically during the end of 2023 ↑ Focus on bonds at the longer end of the muni bond curve as longer-term munis outperformed their intermediate and short-term cohorts ↑ Security selection within non-rated bonds as spreads tightened across this space ↑ Bias towards the lower tiers of the investment-grade universe (bonds rated BBB) and the highest-rated portions of the high-yield universe as spreads tightened in these cohorts ↑ Security selection across a wide range of sectors, including nursing homes, hospitals, airports, and charter schools Top detractors from performance: ↓ Underweight exposure to bonds in Puerto Rico ↓ Security selection across private higher education and multi-family housing Use of derivatives and the impact on performance: The Fund utilized U.S. Treasury futures for yield curve positioning, which had a positive impact on performance. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not necessarily an indication of how the Fund will perform in the future. | |
| Line Graph [Table Text Block] | ||
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS (%) Period Ended July 31, 2024 1 Year 5 Year 10 Year Class C 7.87 1.35 2.98 Class C (with sales charge) 6.87 1.35 2.98 Bloomberg Municipal Bond Index 3.74 1.18 2.47 | |
| 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 current month-end performance, please call Franklin Templeton at (800) 225-1581 or visit https://www.franklintempleton.com/investments/options/mutual-funds . Important data provider notices and terms available at www.franklintempletondatasources.com. | |
| Net Assets | $ 688,773,603 | |
| Holdings Count | $ / shares | 409 | [5] |
| Advisory Fees Paid, Amount | $ 3,098,608 | |
| Investment Company Portfolio Turnover | 25% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (as of July 31, 2024) Total Net Assets $688,773,603 Total Number of Portfolio Holdings * 409 Total Management Fee Paid $3,098,608 Portfolio Turnover Rate 25% | [5] |
| Holdings [Text Block] | [6] | |
| Material Fund Change [Text Block] | HOW HAS THE FUND CHANGED? On May 31, 2023, Franklin Resources, Inc. (“Franklin Resources”) and Great-West Lifeco Inc., the parent company of Putnam U.S. Holdings I, LLC (“Putnam Holdings”), announced that they had entered into a definitive agreement for a subsidiary of Franklin Resources to acquire Putnam Holdings in a stock and cash transaction (the “Transaction”). The Transaction was completed on January 1, 2024. As part of the Transaction, your Fund’s then-current investment advisor, Putnam Investment Management, LLC (“Putnam Management”), a wholly-owned subsidiary of Putnam Holdings, and your Fund’s sub-advisor, Putnam Investments Limited (“PIL”), an indirect, wholly-owned subsidiary of Putnam Holdings, became indirect, wholly-owned subsidiaries of Franklin Resources. In connection with the Transaction, shareholders of your Fund approved a new management contract with Putnam Management and a new sub-advisory contract with PIL. The new contracts are identical to the previous contracts, except for the effective dates, initial terms, updates to fund names as necessary to reflect previous name changes, and certain non-substantive changes. Effective July 15, 2024, Putnam Management transferred its management contract for your Fund to Franklin Advisers, Inc. (“Franklin Advisers”), and Franklin Advisers replaced Putnam Management as the investment advisor to your Fund. In connection with the transfer, your Fund’s portfolio managers, along with supporting research analysts and certain other investment staff of Putnam Management, also became employees of Franklin Advisers. Putnam Management also transferred to Franklin Advisers its sub-management agreement with PIL in respect of your Fund. Franklin Advisers is an indirect, wholly-owned subsidiary of Franklin Resources. In addition, effective July 15, 2024, Franklin Advisers retained Putnam Management as a sub-advisor to your Fund pursuant to a new subadvisory agreement. This is a summary of certain changes to the Fund since August 1, 2023. For more complete information, you may review the Fund’s current prospectus and any applicable supplements at https://www.franklintempleton.com/regulatory-fund-documents or upon request at (800) 225-1581 or funddocuments putnam.com . | |
| Updated Prospectus Phone Number | (800) 225-1581 | |
| Updated Prospectus Email Address | funddocuments@putnam.com | |
| Updated Prospectus Web Address | https://www.franklintempleton.com/regulatory-fund-documents | |
| Class R6 | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Putnam Tax-Free High Yield Fund | |
| Class Name | Class R6 | |
| Trading Symbol | PTFRX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about Putnam Tax-Free High Yield Fund for the period August 1, 2023, to July 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| 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 . | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the reporting period. | |
| 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 YEAR? (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 $72 0.69% | |
| Expenses Paid, Amount | $ 72 | |
| Expense Ratio, Percent | 0.69% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR AND WHAT AFFECTED ITS PERFORMANCE? For the twelve months ended July 31, 2024, Class R6 shares of Putnam Tax-Free High Yield Fund returned 8.97%. The Fund compares its performance to the Bloomberg Municipal Bond Index, which returned 3.74% for the same period. PERFORMANCE HIGHLIGHTS Top contributors to performance: ↑ Long duration position as municipal bonds (munis) moved in sync with falling U.S. Treasury yields, specifically during the end of 2023 ↑ Focus on bonds at the longer end of the muni bond curve as longer-term munis outperformed their intermediate and short-term cohorts ↑ Security selection within non-rated bonds as spreads tightened across this space ↑ Bias towards the lower tiers of the investment-grade universe (bonds rated BBB) and the highest-rated portions of the high-yield universe as spreads tightened in these cohorts ↑ Security selection across a wide range of sectors, including nursing homes, hospitals, airports, and charter schools Top detractors from performance: ↓ Underweight exposure to bonds in Puerto Rico ↓ Security selection across private higher education and multi-family housing Use of derivatives and the impact on performance: The Fund utilized U.S. Treasury futures for yield curve positioning, which had a positive impact on performance. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not necessarily an indication of how the Fund will perform in the future. | |
| Line Graph [Table Text Block] | ||
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS (%) Period Ended July 31, 2024 1 Year 5 Year 10 Year Class R6 8.97 2.38 3.86 Bloomberg Municipal Bond Index 3.74 1.18 2.47 | |
| 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 current month-end performance, please call Franklin Templeton at (800) 225-1581 or visit https://www.franklintempleton.com/investments/options/mutual-funds . Important data provider notices and terms available at www.franklintempletondatasources.com. | |
| Net Assets | $ 688,773,603 | |
| Holdings Count | $ / shares | 409 | [7] |
| Advisory Fees Paid, Amount | $ 3,098,608 | |
| Investment Company Portfolio Turnover | 25% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (as of July 31, 2024) Total Net Assets $688,773,603 Total Number of Portfolio Holdings * 409 Total Management Fee Paid $3,098,608 Portfolio Turnover Rate 25% | [7] |
| Holdings [Text Block] | [8] | |
| Material Fund Change [Text Block] | HOW HAS THE FUND CHANGED? On May 31, 2023, Franklin Resources, Inc. (“Franklin Resources”) and Great-West Lifeco Inc., the parent company of Putnam U.S. Holdings I, LLC (“Putnam Holdings”), announced that they had entered into a definitive agreement for a subsidiary of Franklin Resources to acquire Putnam Holdings in a stock and cash transaction (the “Transaction”). The Transaction was completed on January 1, 2024. As part of the Transaction, your Fund’s then-current investment advisor, Putnam Investment Management, LLC (“Putnam Management”), a wholly-owned subsidiary of Putnam Holdings, and your Fund’s sub-advisor, Putnam Investments Limited (“PIL”), an indirect, wholly-owned subsidiary of Putnam Holdings, became indirect, wholly-owned subsidiaries of Franklin Resources. In connection with the Transaction, shareholders of your Fund approved a new management contract with Putnam Management and a new sub-advisory contract with PIL. The new contracts are identical to the previous contracts, except for the effective dates, initial terms, updates to fund names as necessary to reflect previous name changes, and certain non-substantive changes. Effective July 15, 2024, Putnam Management transferred its management contract for your Fund to Franklin Advisers, Inc. (“Franklin Advisers”), and Franklin Advisers replaced Putnam Management as the investment advisor to your Fund. In connection with the transfer, your Fund’s portfolio managers, along with supporting research analysts and certain other investment staff of Putnam Management, also became employees of Franklin Advisers. Putnam Management also transferred to Franklin Advisers its sub-management agreement with PIL in respect of your Fund. Franklin Advisers is an indirect, wholly-owned subsidiary of Franklin Resources. In addition, effective July 15, 2024, Franklin Advisers retained Putnam Management as a sub-advisor to your Fund pursuant to a new subadvisory agreement. This is a summary of certain changes to the Fund since August 1, 2023. For more complete information, you may review the Fund’s current prospectus and any applicable supplements at https://www.franklintempleton.com/regulatory-fund-documents or upon request at (800) 225-1581 or funddocuments putnam.com . | |
| Updated Prospectus Phone Number | (800) 225-1581 | |
| Updated Prospectus Email Address | funddocuments@putnam.com | |
| Updated Prospectus Web Address | https://www.franklintempleton.com/regulatory-fund-documents | |
| Class Y | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Putnam Tax-Free High Yield Fund | |
| Class Name | Class Y | |
| Trading Symbol | PTFYX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about Putnam Tax-Free High Yield Fund for the period August 1, 2023, to July 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| 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 . | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the reporting period. | |
| 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 YEAR? (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 $74 0.71% | |
| Expenses Paid, Amount | $ 74 | |
| Expense Ratio, Percent | 0.71% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR AND WHAT AFFECTED ITS PERFORMANCE? For the twelve months ended July 31, 2024, Class Y shares of Putnam Tax-Free High Yield Fund returned 8.85%. The Fund compares its performance to the Bloomberg Municipal Bond Index, which returned 3.74% for the same period. PERFORMANCE HIGHLIGHTS Top contributors to performance: ↑ Long duration position as municipal bonds (munis) moved in sync with falling U.S. Treasury yields, specifically during the end of 2023 ↑ Focus on bonds at the longer end of the muni bond curve as longer-term munis outperformed their intermediate and short-term cohorts ↑ Security selection within non-rated bonds as spreads tightened across this space ↑ Bias towards the lower tiers of the investment-grade universe (bonds rated BBB) and the highest-rated portions of the high-yield universe as spreads tightened in these cohorts ↑ Security selection across a wide range of sectors, including nursing homes, hospitals, airports, and charter schools Top detractors from performance: ↓ Underweight exposure to bonds in Puerto Rico ↓ Security selection across private higher education and multi-family housing Use of derivatives and the impact on performance: The Fund utilized U.S. Treasury futures for yield curve positioning, which had a positive impact on performance. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not necessarily an indication of how the Fund will perform in the future. | |
| Line Graph [Table Text Block] | ||
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS (%) Period Ended July 31, 2024 1 Year 5 Year 10 Year Class Y 8.85 2.36 3.85 Bloomberg Municipal Bond Index 3.74 1.18 2.47 | |
| 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 current month-end performance, please call Franklin Templeton at (800) 225-1581 or visit https://www.franklintempleton.com/investments/options/mutual-funds . Important data provider notices and terms available at www.franklintempletondatasources.com. | |
| Net Assets | $ 688,773,603 | |
| Holdings Count | $ / shares | 409 | [9] |
| Advisory Fees Paid, Amount | $ 3,098,608 | |
| Investment Company Portfolio Turnover | 25% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (as of July 31, 2024) Total Net Assets $688,773,603 Total Number of Portfolio Holdings * 409 Total Management Fee Paid $3,098,608 Portfolio Turnover Rate 25% | [9] |
| Holdings [Text Block] | [10] | |
| Material Fund Change [Text Block] | HOW HAS THE FUND CHANGED? On May 31, 2023, Franklin Resources, Inc. (“Franklin Resources”) and Great-West Lifeco Inc., the parent company of Putnam U.S. Holdings I, LLC (“Putnam Holdings”), announced that they had entered into a definitive agreement for a subsidiary of Franklin Resources to acquire Putnam Holdings in a stock and cash transaction (the “Transaction”). The Transaction was completed on January 1, 2024. As part of the Transaction, your Fund’s then-current investment advisor, Putnam Investment Management, LLC (“Putnam Management”), a wholly-owned subsidiary of Putnam Holdings, and your Fund’s sub-advisor, Putnam Investments Limited (“PIL”), an indirect, wholly-owned subsidiary of Putnam Holdings, became indirect, wholly-owned subsidiaries of Franklin Resources. In connection with the Transaction, shareholders of your Fund approved a new management contract with Putnam Management and a new sub-advisory contract with PIL. The new contracts are identical to the previous contracts, except for the effective dates, initial terms, updates to fund names as necessary to reflect previous name changes, and certain non-substantive changes. Effective July 15, 2024, Putnam Management transferred its management contract for your Fund to Franklin Advisers, Inc. (“Franklin Advisers”), and Franklin Advisers replaced Putnam Management as the investment advisor to your Fund. In connection with the transfer, your Fund’s portfolio managers, along with supporting research analysts and certain other investment staff of Putnam Management, also became employees of Franklin Advisers. Putnam Management also transferred to Franklin Advisers its sub-management agreement with PIL in respect of your Fund. Franklin Advisers is an indirect, wholly-owned subsidiary of Franklin Resources. In addition, effective July 15, 2024, Franklin Advisers retained Putnam Management as a sub-advisor to your Fund pursuant to a new subadvisory agreement. This is a summary of certain changes to the Fund since August 1, 2023. For more complete information, you may review the Fund’s current prospectus and any applicable supplements at https://www.franklintempleton.com/regulatory-fund-documents or upon request at (800) 225-1581 or funddocuments putnam.com . | |
| Updated Prospectus Phone Number | (800) 225-1581 | |
| Updated Prospectus Email Address | funddocuments@putnam.com | |
| Updated Prospectus Web Address | https://www.franklintempleton.com/regulatory-fund-documents | |
| [1] * Includes derivatives, if applicable. Cash and Equivalents, if any, represent the market value weights of cash, derivatives, short-term securities, and other unclassified assets in the portfolio. Holdings and allocations may vary over time. * Includes derivatives, if applicable. Cash and Equivalents, if any, represent the market value weights of cash, derivatives, short-term securities, and other unclassified assets in the portfolio. Holdings and allocations may vary over time. * Includes derivatives, if applicable. Cash and Equivalents, if any, represent the market value weights of cash, derivatives, short-term securities, and other unclassified assets in the portfolio. Holdings and allocations may vary over time. * Includes derivatives, if applicable. Cash and Equivalents, if any, represent the market value weights of cash, derivatives, short-term securities, and other unclassified assets in the portfolio. Holdings and allocations may vary over time. * Includes derivatives, if applicable. Cash and Equivalents, if any, represent the market value weights of cash, derivatives, short-term securities, and other unclassified assets in the portfolio. Holdings and allocations may vary over time. | ||
| Shareholder Report, Line Graph (Details) - USD ($) | 12 Months Ended | ||||||||||
| Jul. 31, 2024 | Jul. 31, 2023 | Jul. 31, 2022 | Jul. 31, 2021 | Jul. 31, 2020 | Jul. 31, 2019 | Jul. 31, 2018 | Jul. 31, 2017 | Jul. 31, 2016 | Jul. 31, 2015 | Jul. 31, 2014 | |
| Class A | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Class A (with sales charge) | ||||||||||
| Account Value | $ 13,670 | $ 12,588 | $ 12,633 | $ 13,899 | $ 12,682 | $ 12,318 | $ 11,514 | $ 11,092 | $ 11,075 | $ 10,126 | $ 9,600 |
| Class B | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Class B (with sales charge) | ||||||||||
| Account Value | $ 13,570 | 12,495 | 12,540 | 13,872 | 12,736 | 12,444 | 11,696 | 11,347 | 11,401 | 10,491 | 10,000 |
| Class C | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Class C (with sales charge) | ||||||||||
| Account Value | $ 13,409 | 12,348 | 12,392 | 13,737 | 12,621 | 12,351 | 11,636 | 11,296 | 11,367 | 10,475 | 10,000 |
| Class R6 | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Class R6 | ||||||||||
| Account Value | $ 14,607 | 13,405 | 13,425 | 14,736 | 13,403 | 12,986 | 12,103 | 11,638 | 11,593 | 10,579 | 10,000 |
| Class Y | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Class Y | ||||||||||
| Account Value | $ 14,585 | 13,400 | 13,423 | 14,723 | 13,403 | 12,979 | 12,107 | 11,638 | 11,593 | 10,579 | 10,000 |
| Bloomberg Municipal Bond Index [Member] | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Bloomberg Municipal Bond Index | ||||||||||
| Account Value | $ 12,762 | 12,301 | 12,188 | 13,095 | 12,678 | 12,033 | 11,214 | 11,104 | 11,075 | 10,356 | 10,000 |
| Bloomberg Municipal Bond Index [Member] | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Bloomberg Municipal Bond Index | ||||||||||
| Account Value | $ 12,762 | 12,301 | 12,188 | 13,095 | 12,678 | 12,033 | 11,214 | 11,104 | 11,075 | 10,356 | 10,000 |
| Bloomberg Municipal Bond Index [Member] | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Bloomberg Municipal Bond Index | ||||||||||
| Account Value | $ 12,762 | 12,301 | 12,188 | 13,095 | 12,678 | 12,033 | 11,214 | 11,104 | 11,075 | 10,356 | 10,000 |
| Bloomberg Municipal Bond Index [Member] | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Bloomberg Municipal Bond Index | ||||||||||
| Account Value | $ 12,762 | 12,301 | 12,188 | 13,095 | 12,678 | 12,033 | 11,214 | 11,104 | 11,075 | 10,356 | 10,000 |
| Bloomberg Municipal Bond Index [Member] | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Bloomberg Municipal Bond Index | ||||||||||
| Account Value | $ 12,762 | $ 12,301 | $ 12,188 | $ 13,095 | $ 12,678 | $ 12,033 | $ 11,214 | $ 11,104 | $ 11,075 | $ 10,356 | $ 10,000 |
| Shareholder Report, Average Annual Return (Details) | 12 Months Ended | 60 Months Ended | 120 Months Ended |
| Jul. 31, 2024 | Jul. 31, 2024 | Jul. 31, 2024 | |
| Class A | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | Class A (with sales charge) | ||
| Average Annual Return, Percent | 4.25% | 1.27% | 3.18% |
| Class B | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | Class B (with sales charge) | ||
| Average Annual Return, Percent | 2.93% | 1.14% | 3.10% |
| Class C | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | Class C (with sales charge) | ||
| Average Annual Return, Percent | 6.87% | 1.35% | 2.98% |
| Class R6 | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | Class R6 | ||
| Average Annual Return, Percent | 8.97% | 2.38% | 3.86% |
| Class Y | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | Class Y | ||
| Average Annual Return, Percent | 8.85% | 2.36% | 3.85% |
| Without Sales Load [Member] | Class A | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | Class A | ||
| Average Annual Return, Percent | 8.60% | 2.10% | 3.60% |
| Without Sales Load [Member] | Class B | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | Class B | ||
| Average Annual Return, Percent | 7.93% | 1.48% | 3.10% |
| Without Sales Load [Member] | Class C | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | Class C | ||
| Average Annual Return, Percent | 7.87% | 1.35% | 2.98% |
| Bloomberg Municipal Bond Index [Member] | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | Bloomberg Municipal Bond Index | ||
| Average Annual Return, Percent | 3.74% | 1.18% | 2.47% |
| Bloomberg Municipal Bond Index [Member] | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | Bloomberg Municipal Bond Index | ||
| Average Annual Return, Percent | 3.74% | 1.18% | 2.47% |
| Bloomberg Municipal Bond Index [Member] | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | Bloomberg Municipal Bond Index | ||
| Average Annual Return, Percent | 3.74% | 1.18% | 2.47% |
| Bloomberg Municipal Bond Index [Member] | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | Bloomberg Municipal Bond Index | ||
| Average Annual Return, Percent | 3.74% | 1.18% | 2.47% |
| Bloomberg Municipal Bond Index [Member] | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | Bloomberg Municipal Bond Index | ||
| Average Annual Return, Percent | 3.74% | 1.18% | 2.47% |
| Shareholder Report, Holdings (Details) | Jul. 31, 2024 |
| Class A | Education [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 25.90% |
| Class A | Health Care [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.10% |
| Class A | Land [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.80% |
| Class A | Housing [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.80% |
| Class A | Transportation [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.40% |
| Class A | State General Obligation [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.10% |
| Class A | Local General Obligation [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Class A | Other [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Class A | Tobacco [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Class A | Special Tax [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.40% |
| Class A | Utilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| Class A | Financials [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.80% |
| Class A | Prerefunded [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Class A | Industrials [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Class A | Cash and Equivalents [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| Class B | Education [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 25.90% |
| Class B | Health Care [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.10% |
| Class B | Land [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.80% |
| Class B | Housing [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.80% |
| Class B | Transportation [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.40% |
| Class B | State General Obligation [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.10% |
| Class B | Local General Obligation [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Class B | Other [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Class B | Tobacco [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Class B | Special Tax [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.40% |
| Class B | Utilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| Class B | Financials [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.80% |
| Class B | Prerefunded [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Class B | Industrials [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Class B | Cash and Equivalents [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| Class C | Education [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 25.90% |
| Class C | Health Care [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.10% |
| Class C | Land [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.80% |
| Class C | Housing [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.80% |
| Class C | Transportation [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.40% |
| Class C | State General Obligation [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.10% |
| Class C | Local General Obligation [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Class C | Other [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Class C | Tobacco [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Class C | Special Tax [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.40% |
| Class C | Utilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| Class C | Financials [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.80% |
| Class C | Prerefunded [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Class C | Industrials [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Class C | Cash and Equivalents [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| Class R6 | Education [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 25.90% |
| Class R6 | Health Care [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.10% |
| Class R6 | Land [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.80% |
| Class R6 | Housing [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.80% |
| Class R6 | Transportation [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.40% |
| Class R6 | State General Obligation [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.10% |
| Class R6 | Local General Obligation [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Class R6 | Other [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Class R6 | Tobacco [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Class R6 | Special Tax [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.40% |
| Class R6 | Utilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| Class R6 | Financials [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.80% |
| Class R6 | Prerefunded [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Class R6 | Industrials [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Class R6 | Cash and Equivalents [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| Class Y | Education [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 25.90% |
| Class Y | Health Care [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.10% |
| Class Y | Land [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.80% |
| Class Y | Housing [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.80% |
| Class Y | Transportation [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.40% |
| Class Y | State General Obligation [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.10% |
| Class Y | Local General Obligation [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Class Y | Other [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Class Y | Tobacco [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Class Y | Special Tax [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.40% |
| Class Y | Utilities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| Class Y | Financials [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.80% |
| Class Y | Prerefunded [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Class Y | Industrials [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Class Y | Cash and Equivalents [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
