Basis of Presentation	6 Months Ended
Basis of Presentation	Mar. 28, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation General The accompanying unaudited condensed consolidated financial statements include the accounts of PTC Inc. and its wholly owned subsidiaries and have been prepared by management in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP) and in accordance with the rules and regulations of the Securities and Exchange Commission regarding interim financial reporting. Accordingly, they do not include all the information and footnotes required by generally accepted accounting principles for complete financial statements. While we believe that the disclosures presented are adequate in order to make the information not misleading, these unaudited quarterly financial statements should be read in conjunction with our annual consolidated financial statements and related notes included in our Annual Report on Form 10-K for the fiscal year ended September 30, 2019. In the opinion of management, the accompanying unaudited condensed consolidated financial statements contain all adjustments, consisting only of those of a normal recurring nature, necessary for a fair statement of our financial position, results of operations and cash flows at the dates and for the periods indicated. The September 30, 2019 Consolidated Balance Sheet included herein is derived from our audited consolidated financial statements. Unless otherwise indicated, all references to a year mean our fiscal year, which ends on September 30. Our fiscal quarters end on a Saturday following a thirteen-week calendar and may result in different quarter end dates year to year. The second quarter of 2020 ended on March 28, 2020 and the second quarter of 2019 ended on March 30, 2019. The results of operations for the six months ended March 28, 2020 are not necessarily indicative of the results expected for the remainder of the fiscal year. We adjusted the $3.0 million hedge gain in the Consolidated Statement of Comprehensive Income (Loss) for the three months ended March 30, 2019 that was incorrectly reflected as a loss. Risks and Uncertainties - COVID-19 Pandemic In December 2019, a novel strain of coronavirus, now referred to as COVID-19, surfaced. The virus has spread to over 100 countries, including the United States, and has been declared a pandemic by the World Health Organization. The COVID-19 pandemic has significantly impacted global economic activity and has created future macroeconomic uncertainty. We assessed certain accounting matters that generally require consideration of forecasted financial information in context with the information reasonably available to us and the unknown future impacts COVID-19 as of March 28, 2020 and through the date of this report. The accounting matters assessed included, but were not limited to, our allowance for doubtful accounts, stock-based compensation, the carrying value of our goodwill and other long-lived assets, financial assets, valuation allowances for tax assets and revenue recognition. While there was not a material impact to our consolidated financial statements as of and for the quarter ended March 28, 2020, resulting from our assessments, our future assessment of our current expectations at that time of the magnitude and duration of COVID-19, as well as other factors, could result in material impacts to our consolidated financial statements in future reporting periods. Recent Accounting Pronouncements Recently Adopted Accounting Pronouncements Leases In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update (ASU) 2016-02, Leases (Topic 842) (ASC 842), which replaced the existing guidance in ASC 840, Leases. The updated standard aims to increase transparency and comparability among organizations by requiring lessees to recognize lease assets and lease liabilities on the balance sheet and to disclose important information about leasing arrangements. We adopted ASC 842 effective October 1, 2019 (the effective date). ASC 842 requires a modified retrospective transition method that could either be applied at the earliest comparative period in the financial statements or in the period of adoption. We elected to use the period of adoption (October 1, 2019) transition method and therefore did not recast prior periods. Since we adopted the new standard using the period of adoption transition method, we are not required to present 2020 comparative disclosures under ASC 842. However, we are required to present the required annual disclosures under the previous U.S. GAAP lease accounting standard (ASC 840). We elected the package of practical expedients as permitted under the transition guidance, which allowed us: (1) to carry forward the historical lease classification; (2) not to reassess whether expired or existing contracts are or contain leases; and, (3) not to reassess the treatment of initial direct costs for existing leases. In addition, we elected an accounting policy to not recognize leases with an initial term of one year or less on the balance sheet. Upon the adoption of this standard on October 1, 2019, we recognized an operating lease liability of $224.0 million, representing the present value of the minimum lease payments remaining as of the adoption date, and a right-of-use asset in the amount of $167.9 million. The right-of-use asset reflects adjustments for derecognition of deferred leasing incentives. We also recorded a $1.6 million decrease to retained earnings as a result of the change in scheduling of reversal of temporary tax differences due to the adoption of ASC 842. Pending Accounting Pronouncements Goodwill and Other—Internal-Use Software In August 2018, the FASB issued Accounting Standards Update (ASU) 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract, which aligns the requirements for capitalizing implementation costs in cloud computing arrangements with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The new standard will be effective for us in the first quarter of 2021. Entities can choose to adopt the new guidance prospectively or retrospectively. We plan to adopt this standard using the prospective adoption approach. We are currently evaluating the effects of this pronouncement on our consolidated financial statements. Fair Value Measurement In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement, which eliminates, modifies and adds disclosure requirements for fair value measurements. The new standard will be effective for us in the first quarter of 2021. We do not expect this ASU to have a material impact on our consolidated financial statements. Financial Instruments—Credit Losses In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, along with subsequent amendments, which replace the incurred loss impairment methodology in current U.S. GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information when recording credit loss estimates. The new standard will be effective for us in the first quarter of 2021. We are currently evaluating the impact the standard will have on our consolidated financial statements, but at this time we do not expect it to be significant.