| Form N-CSR Cover | 6 Months Ended |
| Aug. 31, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | JPMorgan Trust IV |
| Entity Central Index Key | 0001659326 |
| Document Period End Date | Aug. 31, 2024 |
| Shareholder Report | 6 Months Ended | |
| Aug. 31, 2024 USD ($) Holding | ||
| Shareholder Report [Line Items] | ||
| Document Type | N-CSRS | |
| Amendment Flag | false | |
| Registrant Name | JPMorgan Trust IV | |
| Entity Central Index Key | 0001659326 | |
| Document Period End Date | Aug. 31, 2024 | |
| C000204674 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | JPMorgan Securities Lending Money Market Fund | |
| Class Name | Agency SL Shares | |
| Trading Symbol | VSLXX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the JPMorgan Securities Lending Money Market Fund for the period March 1, 2024 to August 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 www.jpmorganfunds.com/funddocuments. You can also request this information by contacting us at 1-800-766-7722 or by sending an e-mail request to global_liquidity_funds_services_us@jpmorganfunds.com or by asking any financial intermediary that offers shares of the Fund. | |
| Additional Information Phone Number | 1-800-766-7722 | |
| Additional Information Email | global_liquidity_funds_services_us@jpmorganfunds.com | |
| Additional Information Website | www.jpmorganfunds.com/funddocuments | |
| Expenses [Text Block] | What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment) Fund (Class) Costs of a Costs paid as a percentage * JPMorgan Securities Lending Money Market Fund $ 0.06 % * This charge is annualized. | |
| Expenses Paid, Amount | $ 3 | |
| Expense Ratio, Percent | 0.06% | [1] |
| Net Assets | $ 653,156,000 | |
| Holdings Count | Holding | 43 | |
| Additional Fund Statistics [Text Block] | Fund net assets (000's) $ Total number of portfolio holdings $ | |
| Holdings [Text Block] | EFFECTIVE MATURITY 2–7 calendar days 82.4 31–60 calendar days 6.1 61–90 calendar days 3.0 91–180 calendar days 8.5 | |
| C000166084 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | JPMorgan Ultra-Short Municipal Fund | |
| Class Name | Class A Shares | |
| Trading Symbol | USMSX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the JPMorgan Ultra-Short Municipal Fund for the period March 1, 2024 to August 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 www.jpmorganfunds.com/funddocuments. You can also request this information by contacting us at 1-800-480-4111 or by sending an e-mail request to Funds.Website.Support@jpmorganfunds.com or by asking any financial intermediary that offers shares of the Fund. | |
| Additional Information Phone Number | 1-800-480-4111 | |
| Additional Information Email | Funds.Website.Support@jpmorganfunds.com | |
| Additional Information Website | www.jpmorganfunds.com/funddocuments | |
| Expenses [Text Block] | What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment) Fund (Class) Costs of a Costs paid as a percentage * JPMorgan Ultra-Short Municipal Fund $ 0.44 % * This charge is annualized. | |
| Expenses Paid, Amount | $ 22 | |
| Expense Ratio, Percent | 0.44% | [2] |
| Net Assets | $ 1,920,634,000 | |
| Holdings Count | Holding | 1,684 | |
| Investment Company Portfolio Turnover | 41% | |
| Additional Fund Statistics [Text Block] | Fund net assets (000's) $ Total number of portfolio holdings $ Portfolio turnover rate $ % | |
| Holdings [Text Block] | CREDIT QUALITY ALLOCATIONS (a) Amount rounds to less than 0.1%. | |
| C000166085 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | JPMorgan Ultra-Short Municipal Fund | |
| Class Name | Class I Shares | |
| Trading Symbol | USMTX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the JPMorgan Ultra-Short Municipal Fund for the period March 1, 2024 to August 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 www.jpmorganfunds.com/funddocuments. You can also request this information by contacting us at 1-800-480-4111 or by sending an e-mail request to Funds.Website.Support@jpmorganfunds.com or by asking any financial intermediary that offers shares of the Fund. | |
| Additional Information Phone Number | 1-800-480-4111 | |
| Additional Information Email | Funds.Website.Support@jpmorganfunds.com | |
| Additional Information Website | www.jpmorganfunds.com/funddocuments | |
| Expenses [Text Block] | What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment) Fund (Class) Costs of a Costs paid as a percentage * JPMorgan Ultra-Short Municipal Fund $ 0.24 % * This charge is annualized. | |
| Expenses Paid, Amount | $ 12 | |
| Expense Ratio, Percent | 0.24% | [3] |
| Net Assets | $ 1,920,634,000 | |
| Holdings Count | Holding | 1,684 | |
| Investment Company Portfolio Turnover | 41% | |
| Additional Fund Statistics [Text Block] | Fund net assets (000's) $ Total number of portfolio holdings $ Portfolio turnover rate $ % | |
| Holdings [Text Block] | CREDIT QUALITY ALLOCATIONS (a) Amount rounds to less than 0.1%. | |
| C000198351 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | JPMorgan Institutional Tax Free Money Market Fund | |
| Class Name | Agency Shares | |
| Trading Symbol | JOAXX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the JPMorgan Institutional Tax Free Money Market Fund for the period March 1, 2024 to August 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 www.jpmorganfunds.com/funddocuments. You can also request this information by contacting us at 1-800-766-7722 or by sending an e-mail request to global_liquidity_funds_services_us@jpmorganfunds.com or by asking any financial intermediary that offers shares of the Fund. | |
| Additional Information Phone Number | 1-800-766-7722 | |
| Additional Information Email | global_liquidity_funds_services_us@jpmorganfunds.com | |
| Additional Information Website | www.jpmorganfunds.com/funddocuments | |
| Expenses [Text Block] | What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment) Fund (Class) Costs of a Costs paid as a percentage * JPMorgan Institutional Tax Free Money Market Fund $ 0.26 % * This charge is annualized. | |
| Expenses Paid, Amount | $ 13 | |
| Expense Ratio, Percent | 0.26% | [4] |
| Net Assets | $ 1,960,939,000 | |
| Holdings Count | Holding | 263 | |
| Additional Fund Statistics [Text Block] | Fund net assets (000's) $ Total number of portfolio holdings $ | |
| Holdings [Text Block] | EFFECTIVE MATURITY 2–7 calendar days 49.0 8–30 calendar days 51.0 | |
| C000198352 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | JPMorgan Institutional Tax Free Money Market Fund | |
| Class Name | Capital Shares | |
| Trading Symbol | JOCXX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the JPMorgan Institutional Tax Free Money Market Fund for the period March 1, 2024 to August 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 www.jpmorganfunds.com/funddocuments. You can also request this information by contacting us at 1-800-766-7722 or by sending an e-mail request to global_liquidity_funds_services_us@jpmorganfunds.com or by asking any financial intermediary that offers shares of the Fund. | |
| Additional Information Phone Number | 1-800-766-7722 | |
| Additional Information Email | global_liquidity_funds_services_us@jpmorganfunds.com | |
| Additional Information Website | www.jpmorganfunds.com/funddocuments | |
| Expenses [Text Block] | What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment) Fund (Class) Costs of a Costs paid as a percentage * JPMorgan Institutional Tax Free Money Market Fund $ 0.18 % * This charge is annualized. | |
| Expenses Paid, Amount | $ 9 | |
| Expense Ratio, Percent | 0.18% | [5] |
| Net Assets | $ 1,960,939,000 | |
| Holdings Count | Holding | 263 | |
| Additional Fund Statistics [Text Block] | Fund net assets (000's) $ Total number of portfolio holdings $ | |
| Holdings [Text Block] | EFFECTIVE MATURITY 2–7 calendar days 49.0 8–30 calendar days 51.0 | |
| C000198353 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | JPMorgan Institutional Tax Free Money Market Fund | |
| Class Name | IM Shares | |
| Trading Symbol | JOIXX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the JPMorgan Institutional Tax Free Money Market Fund for the period March 1, 2024 to August 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 www.jpmorganfunds.com/jpmfpages/imshares. You can also request this information by contacting us at 1-800-766-7722 or by sending an e-mail request to global_liquidity_funds_services_us@jpmorganfunds.com or by asking any financial intermediary that offers shares of the Fund. | |
| Additional Information Phone Number | 1-800-766-7722 | |
| Additional Information Email | global_liquidity_funds_services_us@jpmorganfunds.com | |
| Additional Information Website | www.jpmorganfunds.com/jpmfpages/imshares | |
| Expenses [Text Block] | What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment) Fund (Class) Costs of a Costs paid as a percentage * JPMorgan Institutional Tax Free Money Market Fund $ 0.14 % * This charge is annualized. | |
| Expenses Paid, Amount | $ 7 | |
| Expense Ratio, Percent | 0.14% | [6] |
| Net Assets | $ 1,960,939,000 | |
| Holdings Count | Holding | 263 | |
| Additional Fund Statistics [Text Block] | Fund net assets (000's) $ Total number of portfolio holdings $ | |
| Holdings [Text Block] | EFFECTIVE MATURITY 2–7 calendar days 49.0 8–30 calendar days 51.0 | |
| C000198354 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | JPMorgan Institutional Tax Free Money Market Fund | |
| Class Name | Institutional Class Shares | |
| Trading Symbol | JOFXX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the JPMorgan Institutional Tax Free Money Market Fund for the period March 1, 2024 to August 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 www.jpmorganfunds.com/funddocuments. You can also request this information by contacting us at 1-800-766-7722 or by sending an e-mail request to global_liquidity_funds_services_us@jpmorganfunds.com or by asking any financial intermediary that offers shares of the Fund. | |
| Additional Information Phone Number | 1-800-766-7722 | |
| Additional Information Email | global_liquidity_funds_services_us@jpmorganfunds.com | |
| Additional Information Website | www.jpmorganfunds.com/funddocuments | |
| Expenses [Text Block] | What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment) Fund (Class) Costs of a Costs paid as a percentage * JPMorgan Institutional Tax Free Money Market Fund $ 0.21 % * This charge is annualized. | |
| Expenses Paid, Amount | $ 11 | |
| Expense Ratio, Percent | 0.21% | [7] |
| Net Assets | $ 1,960,939,000 | |
| Holdings Count | Holding | 263 | |
| Additional Fund Statistics [Text Block] | Fund net assets (000's) $ Total number of portfolio holdings $ | |
| Holdings [Text Block] | EFFECTIVE MATURITY 2–7 calendar days 49.0 8–30 calendar days 51.0 | |
| [1]This charge is annualized.[2]This charge is annualized.[3]This charge is annualized.[4]This charge is annualized.[5]This charge is annualized.[6]This charge is annualized.[7]This charge is annualized. | ||
| Shareholder Report, Holdings (Details) | Aug. 31, 2024 | |
| C000204674 [Member] | Two To 7 calendar days [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 82.40% | |
| C000204674 [Member] | Thirty One To 60 calendar days [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 6.10% | |
| C000204674 [Member] | Sixty One To 90 calendar days [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3% | |
| C000204674 [Member] | Ninety One To 180 calendar days [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 8.50% | |
| C000166084 [Member] | A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 17% | |
| C000166084 [Member] | AA [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 27.90% | |
| C000166084 [Member] | AAA [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 38.30% | |
| C000166084 [Member] | BB [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0% | [1] |
| C000166084 [Member] | BBB [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.10% | |
| C000166084 [Member] | NR [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 12.70% | |
| C000166085 [Member] | A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 17% | |
| C000166085 [Member] | AA [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 27.90% | |
| C000166085 [Member] | AAA [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 38.30% | |
| C000166085 [Member] | BB [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0% | [2] |
| C000166085 [Member] | BBB [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.10% | |
| C000166085 [Member] | NR [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 12.70% | |
| C000198351 [Member] | Two To 7 calendar days [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 49% | |
| C000198351 [Member] | Eight To 30 calendar days [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 51% | |
| C000198352 [Member] | Two To 7 calendar days [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 49% | |
| C000198352 [Member] | Eight To 30 calendar days [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 51% | |
| C000198353 [Member] | Two To 7 calendar days [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 49% | |
| C000198353 [Member] | Eight To 30 calendar days [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 51% | |
| C000198354 [Member] | Two To 7 calendar days [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 49% | |
| C000198354 [Member] | Eight To 30 calendar days [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 51% | |
| [1]Amount rounds to less than 0.1%.[2]Amount rounds to less than 0.1%. | ||
