| Line Item | Dec 31, 2025 | Dec 31, 2024 | Dec 31, 2023 | Dec 31, 2022 | Dec 31, 2021 | Dec 31, 2020 | Dec 31, 2019 | Dec 31, 2018 |
|---|---|---|---|---|---|---|---|---|
| EXPENSES | ||||||||
| Exploration and evaluation expenditures | ||||||||
| General and administrative | ||||||||
| Share based compensation | ||||||||
| Share of (loss)/gain of Cauchari-Olaroz Project | ||||||||
| Share of loss of Arena Minerals | ||||||||
| Share of loss of Sal de la Puna Project | ||||||||
| Total expenses | ||||||||
| OTHER ITEMS | ||||||||
| Transaction costs | ||||||||
| (Loss)/gain on financial instruments measured at fair value | ||||||||
| Finance and other costs | ||||||||
| Foreign exchange (loss)/gain | ||||||||
| Finance and other income | ||||||||
| Other Income Expense | ||||||||
| (LOSS)/INCOME FROM CONTINUING OPERATIONS BEFORE TAXES | ||||||||
| Current tax expense | ||||||||
| Deferred tax (expense)/recovery | ||||||||
| (LOSS)/INCOME FROM CONTINUING OPERATIONS | ||||||||
| INCOME FROM DISCONTINUED OPERATIONS | ||||||||
| NET (LOSS)/INCOME | ||||||||
| ATTRIBUTABLE TO: | ||||||||
| Equity holders of Lithium Argentina | ||||||||
| Non-controlling interest | ||||||||
| TOTAL COMPREHENSIVE (LOSS)/INCOME | ||||||||
| Basic earnings per share [abstract] | ||||||||
| (Loss)/income continuing per share - basic | ||||||||
| Income discontinued per share - basic | ||||||||
| (Loss)/income per share - basic | ||||||||
| Diluted earnings per share [abstract] | ||||||||
| (Loss)/income continuing per share - diluted | ||||||||
| Income discontinued per share - diluted | ||||||||
| (Loss)/income per share - diluted |