| Form N-CSR Cover | 6 Months Ended |
| Oct. 31, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | Putnam Investment Funds |
| Entity Central Index Key | 0000932101 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Oct. 31, 2024 |
| Shareholder Report | 6 Months Ended | |
| Oct. 31, 2024 USD ($) $ / shares | ||
| Shareholder Report [Line Items] | ||
| Document Type | N-CSRS | |
| Amendment Flag | false | |
| Registrant Name | Putnam Investment Funds | |
| Entity Central Index Key | 0000932101 | |
| Entity Investment Company Type | N-1A | |
| Document Period End Date | Oct. 31, 2024 | |
| Class A | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Putnam Sustainable Future Fund | |
| Class Name | Class A | |
| Trading Symbol | PMVAX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about Putnam Sustainable Future Fund for the period May 1, 2024, to October 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | semi-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 . | |
| 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 $53 1.01% | [1] |
| Expenses Paid, Amount | $ 53 | |
| Expense Ratio, Percent | 1.01% | |
| Net Assets | $ 418,641,125 | |
| Holdings Count | $ / shares | 118 | [2] |
| Investment Company Portfolio Turnover | 29% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (as of October 31, 2024) Total Net Assets $418,641,125 Total Number of Portfolio Holdings * 118 Portfolio Turnover Rate 29% | [2] |
| Holdings [Text Block] | [3] | |
| Updated Prospectus Web Address | https://www.franklintempleton.com/regulatory-fund-documents | |
| Class C | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Putnam Sustainable Future Fund | |
| Class Name | Class C | |
| Trading Symbol | PMPCX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about Putnam Sustainable Future Fund for the period May 1, 2024, to October 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | semi-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 . | |
| 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 $92 1.76% | [4] |
| Expenses Paid, Amount | $ 92 | |
| Expense Ratio, Percent | 1.76% | |
| Net Assets | $ 418,641,125 | |
| Holdings Count | $ / shares | 118 | [5] |
| Investment Company Portfolio Turnover | 29% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (as of October 31, 2024) Total Net Assets $418,641,125 Total Number of Portfolio Holdings * 118 Portfolio Turnover Rate 29% | [5] |
| Holdings [Text Block] | [6] | |
| Updated Prospectus Web Address | https://www.franklintempleton.com/regulatory-fund-documents | |
| Class R | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Putnam Sustainable Future Fund | |
| Class Name | Class R | |
| Trading Symbol | PMVRX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about Putnam Sustainable Future Fund for the period May 1, 2024, to October 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | semi-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 . | |
| 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 $66 1.26% | [7] |
| Expenses Paid, Amount | $ 66 | |
| Expense Ratio, Percent | 1.26% | |
| Net Assets | $ 418,641,125 | |
| Holdings Count | $ / shares | 118 | [8] |
| Investment Company Portfolio Turnover | 29% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (as of October 31, 2024) Total Net Assets $418,641,125 Total Number of Portfolio Holdings * 118 Portfolio Turnover Rate 29% | [8] |
| Holdings [Text Block] | [9] | |
| Updated Prospectus Web Address | https://www.franklintempleton.com/regulatory-fund-documents | |
| Class R6 | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Putnam Sustainable Future Fund | |
| Class Name | Class R6 | |
| Trading Symbol | PNOTX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about Putnam Sustainable Future Fund for the period May 1, 2024, to October 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | semi-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 . | |
| 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 $35 0.66% | [10] |
| Expenses Paid, Amount | $ 35 | |
| Expense Ratio, Percent | 0.66% | |
| Net Assets | $ 418,641,125 | |
| Holdings Count | $ / shares | 118 | [11] |
| Investment Company Portfolio Turnover | 29% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (as of October 31, 2024) Total Net Assets $418,641,125 Total Number of Portfolio Holdings * 118 Portfolio Turnover Rate 29% | [11] |
| Holdings [Text Block] | [12] | |
| Updated Prospectus Web Address | https://www.franklintempleton.com/regulatory-fund-documents | |
| Class Y | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Putnam Sustainable Future Fund | |
| Class Name | Class Y | |
| Trading Symbol | PMVYX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about Putnam Sustainable Future Fund for the period May 1, 2024, to October 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | semi-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 . | |
| 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 $40 0.76% | [13] |
| Expenses Paid, Amount | $ 40 | |
| Expense Ratio, Percent | 0.76% | |
| Net Assets | $ 418,641,125 | |
| Holdings Count | $ / shares | 118 | [14] |
| Investment Company Portfolio Turnover | 29% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (as of October 31, 2024) Total Net Assets $418,641,125 Total Number of Portfolio Holdings * 118 Portfolio Turnover Rate 29% | [14] |
| Holdings [Text Block] | [15] | |
| Updated Prospectus Web Address | https://www.franklintempleton.com/regulatory-fund-documents | |
| [1] † Annualized. * 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. † Annualized. * 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. † Annualized. * 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. † Annualized. * 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. † Annualized. * 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. | ||
| Label | Element | Value |
| Class A | Information Technology [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 23.30% |
| Class A | Health Care [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 18.90% |
| Class A | Industrials [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 17.70% |
| Class A | Financials [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 9.90% |
| Class A | Consumer Discretionary [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 9.70% |
| Class A | Consumer Staples [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 5.20% |
| Class A | Materials [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 4.40% |
| Class A | Utilities [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 4.20% |
| Class A | Real Estate [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 2.10% |
| Class A | Communication Services [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 1.50% |
| Class A | Cash and Equivalents [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 3.10% |
| Label | Element | Value |
| Class C | Information Technology [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 23.30% |
| Class C | Health Care [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 18.90% |
| Class C | Industrials [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 17.70% |
| Class C | Financials [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 9.90% |
| Class C | Consumer Discretionary [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 9.70% |
| Class C | Consumer Staples [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 5.20% |
| Class C | Materials [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 4.40% |
| Class C | Utilities [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 4.20% |
| Class C | Real Estate [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 2.10% |
| Class C | Communication Services [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 1.50% |
| Class C | Cash and Equivalents [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 3.10% |
| Label | Element | Value |
| Class R | Information Technology [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 23.30% |
| Class R | Health Care [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 18.90% |
| Class R | Industrials [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 17.70% |
| Class R | Financials [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 9.90% |
| Class R | Consumer Discretionary [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 9.70% |
| Class R | Consumer Staples [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 5.20% |
| Class R | Materials [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 4.40% |
| Class R | Utilities [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 4.20% |
| Class R | Real Estate [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 2.10% |
| Class R | Communication Services [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 1.50% |
| Class R | Cash and Equivalents [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 3.10% |
| Label | Element | Value |
| Class R6 | Information Technology [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 23.30% |
| Class R6 | Health Care [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 18.90% |
| Class R6 | Industrials [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 17.70% |
| Class R6 | Financials [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 9.90% |
| Class R6 | Consumer Discretionary [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 9.70% |
| Class R6 | Consumer Staples [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 5.20% |
| Class R6 | Materials [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 4.40% |
| Class R6 | Utilities [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 4.20% |
| Class R6 | Real Estate [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 2.10% |
| Class R6 | Communication Services [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 1.50% |
| Class R6 | Cash and Equivalents [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 3.10% |
| Label | Element | Value |
| Class Y | Information Technology [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 23.30% |
| Class Y | Health Care [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 18.90% |
| Class Y | Industrials [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 17.70% |
| Class Y | Financials [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 9.90% |
| Class Y | Consumer Discretionary [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 9.70% |
| Class Y | Consumer Staples [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 5.20% |
| Class Y | Materials [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 4.40% |
| Class Y | Utilities [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 4.20% |
| Class Y | Real Estate [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 2.10% |
| Class Y | Communication Services [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 1.50% |
| Class Y | Cash and Equivalents [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 3.10% |
