Shareholder Report, Line Graph (Details) - USD ($) |
6 Months Ended | 12 Months Ended | 24 Months Ended | 36 Months Ended | 48 Months Ended | 60 Months Ended | 72 Months Ended | 84 Months Ended | 96 Months Ended | 108 Months Ended | 120 Months Ended | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Jun. 30, 2016 |
Jun. 30, 2026 |
Jun. 30, 2017 |
Jun. 30, 2018 |
Jun. 30, 2019 |
Jun. 30, 2020 |
Jun. 30, 2021 |
Jun. 30, 2022 |
Jun. 30, 2023 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2026 |
|
| C000025443 | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Longleaf Partners Fund | |||||||||||
| Accumulated Value | $ 10,000 | $ 12,235 | $ 13,178 | $ 11,668 | $ 10,354 | $ 16,817 | $ 14,144 | $ 15,174 | $ 16,068 | $ 17,491 | $ 17,880 | |
| C000117771 | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Longleaf Partners Global Fund | |||||||||||
| Accumulated Value | 10,000 | 14,289 | 15,058 | 14,288 | 12,879 | 18,103 | 13,734 | 15,363 | 16,380 | 18,957 | 20,725 | |
| C000025444 | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Longleaf Partners Small-Cap Fund | |||||||||||
| Accumulated Value | 10,000 | 11,478 | 12,840 | 12,177 | 9,669 | 15,812 | 13,120 | 13,472 | 15,322 | 17,122 | 16,763 | |
| S&P 500 Index TR | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | S&P 500<sup style="inset: 1.5px 0px 4px; 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; text-align-last: auto; white-space-collapse: preserve-breaks;">®</sup> Index | |||||||||||
| Accumulated Value | 10,000 | 11,790 | 13,484 | 14,889 | 16,006 | 22,536 | 20,144 | 24,091 | 30,006 | 34,556 | 42,271 | |
| MSCI WORLD INDEX Net (USD) | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | MSCI World Index | |||||||||||
| Accumulated Value | 10,000 | 11,820 | 13,130 | 13,961 | 14,358 | 19,964 | 17,102 | 20,267 | 24,360 | 28,320 | 34,363 | |
| Russell 2000 Total Return | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Russell 2000<sup style="inset: 1.5px 0px 4px; 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; text-align-last: auto; white-space-collapse: preserve-breaks;">®</sup> Index | |||||||||||
| Accumulated Value | 10,000 | 12,460 | 14,649 | 14,164 | 13,226 | 21,429 | 16,029 | 18,002 | 19,812 | 21,334 | 30,034 | |
| Russell 1000 Value Total Return | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Russell 1000<sup style="inset: 1.5px 0px 4px; 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; text-align-last: auto; white-space-collapse: preserve-breaks;">®</sup> Value Index | |||||||||||
| Accumulated Value | 10,000 | 11,553 | 12,335 | 13,379 | 12,197 | 17,525 | 16,330 | 18,214 | 20,592 | 23,414 | 29,757 | |
| FTSE Developed Index | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | FTSE Developed Index | |||||||||||
| Accumulated Value | 10,000 | 11,870 | 13,179 | 13,933 | 14,326 | 19,949 | 16,981 | 20,085 | 24,061 | 28,009 | 34,655 | |
| MSCI World Value Index | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | MSCI World Value Index | |||||||||||
| Accumulated Value | 10,000 | 11,868 | 12,528 | 13,059 | 11,581 | 15,971 | 14,912 | 16,500 | 18,793 | 21,788 | 26,328 | |
| Russell 2000 Value Total Return | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Russell 2000<sup style="inset: 1.5px 0px 4px; 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; text-align-last: auto; white-space-collapse: preserve-breaks;">®</sup> Value Index | |||||||||||
| Accumulated Value | 10,000 | 12,486 | 14,121 | 13,241 | 10,927 | 18,934 | 15,851 | 16,803 | 18,634 | 19,666 | 28,123 | |
| Russell 3000 Total Return Index | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Russell 3000<sup style="inset: 1.5px 0px 4px; 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; text-align-last: auto; white-space-collapse: preserve-breaks;">®</sup> Index | |||||||||||
| Accumulated Value | $ 10,000 | $ 11,851 | $ 13,602 | $ 14,824 | $ 15,792 | $ 22,767 | $ 19,610 | $ 23,327 | $ 28,721 | $ 33,114 | $ 40,667 |