v3.26.1
Property and Equipment, Net - Schedule of Depreciation Expense (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Property, Plant, and Equipment [Line Items]        
Total depreciation expense $ 7.5 $ 4.2 $ 13.4 $ 7.9
Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization        
Property, Plant, and Equipment [Line Items]        
Total depreciation expense 0.4 0.0 0.8 0.0
Location, Statement of Income, Balance [Axis]: us-gaap:ResearchAndDevelopmentExpense        
Property, Plant, and Equipment [Line Items]        
Total depreciation expense 6.8 4.1 12.2 7.7
Location, Statement of Income, Balance [Axis]: achr:GeneralAndAdministrativeExpenseCredit        
Property, Plant, and Equipment [Line Items]        
Total depreciation expense $ 0.3 $ 0.1 $ 0.4 $ 0.2