| Form N-CSR Cover | 12 Months Ended |
| Sep. 30, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | Northern Lights Fund Trust III |
| Entity Central Index Key | 0001537140 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Sep. 30, 2024 |
| Shareholder Report | 12 Months Ended |
| Sep. 30, 2024 USD ($) Holding | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | Northern Lights Fund Trust III |
| Entity Central Index Key | 0001537140 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Sep. 30, 2024 |
| C000121227 | |
| Shareholder Report [Line Items] | |
| Fund Name | Persimmon Long/Short Fund |
| Class Name | Class I |
| Trading Symbol | LSEIX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about Persimmon Long/Short Fund for the period of October 1, 2023 to September 30, 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.persimmonfunds.com/documents |
| Additional Information Phone Number | 1-855-233-8300 |
| Additional Information Website | https://www.persimmonfunds.com/documents |
| Expenses [Text Block] | What were the Fund’s 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 I $100 1.92% |
| Expenses Paid, Amount | $ 100 |
| Expense Ratio, Percent | 1.92% |
| Performance Past Does Not Indicate Future [Text] | The Fund's past performance is not a good predictor of how the Fund will perform in the future. |
| Average Annual Return [Table Text Block] | Average Annual Total Returns 1 Year 5 Years 10 Years Persimmon Long/Short Fund Class I 30.14% 9.26% 5.43% HFRX Equity Hedge Index 11.35% 6.01% 3.49% S&P 500 ® 36.35% 15.98% 13.38% The Fund's past performance is not a good predictor of how the Fund will perform in the future. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares. |
| 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. |
| Material Change Date | Sep. 30, 2024 |
| AssetsNet | $ 41,927,487 |
| Holdings Count | Holding | 380 |
| Advisory Fees Paid, Amount | $ 485,368 |
| InvestmentCompanyPortfolioTurnover | 449% |
| Additional Fund Statistics [Text Block] | Fund Statistics Net Assets $41,927,487 Number of Portfolio Holdings 380 Advisory Fee $485,368 Portfolio Turnover 449% |
| Holdings [Text Block] | Asset Weighting (% of total investments) Value Value Common Stocks 96.5% Money Market Funds 2.1% Reit 1.4% Special Case Securities 0.0% |
| Shareholder Report, Line Graph (Details) - USD ($) | 12 Months Ended | ||||||||||
| Sep. 30, 2014 | Sep. 30, 2024 | Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2015 | |
| C000121227 | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Persimmon Long/Short Fund Class I | ||||||||||
| Account Value | $ 10,000 | $ 16,963 | $ 13,034 | $ 12,126 | $ 12,947 | $ 11,491 | $ 10,895 | $ 11,680 | $ 11,031 | $ 10,224 | $ 10,226 |
| S&P 500 Index | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | ®</sup> Index" id="sjs-B9">S&P 500<sup style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 700; grid-area: auto; line-height: 0px; margin: 0px; overflow: visible; position: relative; text-align: center;">®</sup> Index | ||||||||||
| Account Value | $ 10,000 | 35,098 | 25,741 | 21,165 | 25,040 | 19,260 | 16,727 | 16,044 | 13,607 | 11,472 | 9,939 |
| HFRX Equity Hedge Index | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | HFRX Equity Hedge Index | ||||||||||
| Account Value | $ 10,000 | $ 14,095 | $ 12,658 | $ 12,064 | $ 12,344 | $ 10,484 | $ 10,526 | $ 10,675 | $ 10,487 | $ 9,718 | $ 9,705 |
| Shareholder Report, Average Annual Return (Details) | 12 Months Ended | 60 Months Ended | 120 Months Ended | |
| Sep. 30, 2024 | Sep. 30, 2014 | Sep. 30, 2024 | Sep. 30, 2024 | |
| C000121227 | ||||
| Average Annual Return [Line Items] | ||||
| Line Graph and Table Measure Name | Persimmon Long/Short Fund Class I | |||
| Without Sales Load [Member] | C000121227 | ||||
| Average Annual Return [Line Items] | ||||
| Average Annual Return, Percent | 30.14% | 9.26% | 5.43% | |
| S&P 500 Index | ||||
| Average Annual Return [Line Items] | ||||
| Line Graph and Table Measure Name | ®</sup> Index" id="sjs-C11">S&P 500<sup style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 700; grid-area: auto; line-height: 0px; margin: 0px; overflow: visible; position: relative; text-align: center;">®</sup> Index | |||
| Average Annual Return, Percent | 36.35% | 15.98% | 13.38% | |
| HFRX Equity Hedge Index | ||||
| Average Annual Return [Line Items] | ||||
| Line Graph and Table Measure Name | HFRX Equity Hedge Index | |||
| Average Annual Return, Percent | 11.35% | 6.01% | 3.49% | |
| Shareholder Report, Holdings (Details) - C000121227 | Sep. 30, 2024 |
| 037833100 | Apple, Inc. | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.20% |
| 594918104 | Microsoft Corporation | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.60% |
| 67066G104 | NVIDIA Corporation | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.10% |
| 023135106 | Amazon.com, Inc. | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| 084670702 | Berkshire Hathaway, Inc., Class B | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| 02079K305 | Alphabet, Inc., Class A | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| 31846V336 | First American Government Obligations Fund | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.10% |
| 02079K107 | Alphabet, Inc., Class C | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2% |
| 11135F101 | Broadcom, Inc. | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.70% |
| 532457108 | Eli Lilly & Company | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.60% |
| Real Estate | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.50% |
| Money Market Funds | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.10% |
| Materials | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| Utilities | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| Energy | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| Consumer Staples | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.10% |
| Communications | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.40% |
| Industrials | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.90% |
| Consumer Discretionary | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.20% |
| Financials | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.20% |
| Health Care | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.30% |
| Technology | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 35.40% |
| InvestmentType_Common Stocks | |
| Holdings [Line Items] | |
| Percent of Total Investments | 96.50% |
| InvestmentType_Money Market Funds | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| InvestmentType_Reit | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.40% |
| InvestmentType_Special Case Securities | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0% |
