v3.26.3
Software Development, Property and Equipment and Long-Lived Assets - Summary of Depreciation and Amortization Expense (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Property Plant And Equipment [Line Items]        
Depreciation and amortization expense $ 5,311 $ 4,107 $ 14,471 $ 11,063
Location, Statement of Income, Balance [Axis]: us-gaap:CostOfRevenue        
Property Plant And Equipment [Line Items]        
Depreciation and amortization expense 179 184 538 550
Location, Statement of Income, Balance [Axis]: us-gaap:GeneralAndAdministrativeExpense        
Property Plant And Equipment [Line Items]        
Depreciation and amortization expense 62 155 522 539
Location, Statement of Income, Balance [Axis]: us-gaap:ResearchAndDevelopmentExpense        
Property Plant And Equipment [Line Items]        
Depreciation and amortization expense 4,980 3,693 13,213 9,770
Location, Statement of Income, Balance [Axis]: us-gaap:SellingAndMarketingExpense        
Property Plant And Equipment [Line Items]        
Depreciation and amortization expense 14 29 53 75
Location, Statement of Income, Balance [Axis]: xmtr:OperationsAndSupportExpense        
Property Plant And Equipment [Line Items]        
Depreciation and amortization expense $ 76 $ 46 $ 145 $ 129