Stock-based Compensation - Schedule of Classification of Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 59,382	$ 54,032	$ 185,848	$ 161,395
Location, Statement of Income, Balance [Axis]: us-gaap:GeneralAndAdministrativeExpense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	22,593	15,894	66,624	49,678
Location, Statement of Income, Balance [Axis]: us-gaap:ResearchAndDevelopmentExpense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	15,043	17,788	49,115	48,334
Location, Statement of Income, Balance [Axis]: us-gaap:SellingAndMarketingExpense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	16,143	15,059	51,373	46,672
License \| Location, Statement of Income, Balance [Axis]: ptc:CostOfLicenseRevenue
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	61	176	267	282
Support and cloud services \| Location, Statement of Income, Balance [Axis]: ptc:CostOfSupportAndCloudServicesRevenue
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	4,086	4,122	13,548	12,092
Professional services \| Location, Statement of Income, Balance [Axis]: ptc:CostOfProfessionalServicesRevenue
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 1,456	$ 993	$ 4,921	$ 4,337