Stockholders' Equity	12 Months Ended
Sep. 30, 2018
Stockholders' Equity Note [Abstract]
Stockholders' Equity	Stockholders’ Equity Preferred Stock We may issue up to 5.0 million shares of our preferred stock in one or more series. 0.5 million of these shares are designated as Series A Junior Participating Preferred Stock. Our Board of Directors is authorized to fix the rights and terms for any series of preferred stock without additional shareholder approval. Common Stock Our Articles of Organization authorize us to issue up to 500 million shares of our common stock. As part of a strategic alliance, in the fourth quarter of 2018, Rockwell Automation made a $1 billion equity investment in PTC, by acquiring 10,582,010 shares at a price of $94.50 per share. Our Board of Directors has authorized us to repurchase up to $1,500 million of our common stock for the October 1, 2017 through September 30, 2020 period. We intend to use cash from operations and borrowings under our credit facility to make such repurchases. All shares of our common stock repurchased are automatically restored to the status of authorized and unissued. In 2018, we repurchased 9.4 million shares. The repurchases were made under two accelerated repurchase (ASR) agreements. We completed the $100 million ASR repurchase in the third quarter of 2018. We entered into a $1,000 million ASR in July 2018. Shares valued at $800 million in the aggregate were delivered to us upon entry into the ASR. The remaining $200 million represents the amount held back by the bank counterparty pending final settlement of the ASR, which is expected to occur in the second or third quarter of 2019. Upon settlement of the ASR, the total shares repurchased by us will equal $1,000 million divided by the average daily volume weighted-average price of our common stock during the term of the ASR program less a fixed per share discount. We used the $1 billion in proceeds from the Rockwell Automation investment in PTC and $100 million of cash from operations to make the repurchases. In 2017, we repurchased 0.9 million shares at cost of $51.0 million. In 2016, we did not repurchase any shares due to our transition to a subscription business model and the near-term impact on free cash flow and EBITDA.

Stockholders’ Equity

Preferred Stock

We may issue up to 5.0 million shares of our preferred stock in one or more series. 0.5 million of these shares are designated as Series A Junior Participating Preferred Stock. Our Board of Directors is authorized to fix the rights and terms for any series of preferred stock without additional shareholder approval.

Common Stock

Our Articles of Organization authorize us to issue up to 500 million shares of our common stock. As part of a strategic alliance, in the fourth quarter of 2018, Rockwell Automation made a $1 billion equity investment in PTC, by acquiring 10,582,010 shares at a price of $94.50 per share.

Our Board of Directors has authorized us to repurchase up to $1,500 million of our common stock for the October 1, 2017 through September 30, 2020 period.

We intend to use cash from operations and borrowings under our credit facility to make such repurchases. All shares of our common stock repurchased are automatically restored to the status of authorized and unissued.

In 2018, we repurchased 9.4 million shares. The repurchases were made under two accelerated repurchase (ASR) agreements. We completed the $100 million ASR repurchase in the third quarter of 2018. We entered into a $1,000 million ASR in July 2018. Shares valued at $800 million in the aggregate were delivered to us upon entry into the ASR. The remaining $200 million represents the amount held back by the bank counterparty pending final settlement of the ASR, which is expected to occur in the second or third quarter of 2019. Upon settlement of the ASR, the total shares repurchased by us will equal $1,000 million divided by the average daily volume weighted-average price of our common stock during the term of the ASR program less a fixed per share discount. We used the $1 billion in proceeds from the Rockwell Automation investment in PTC and $100 million of cash from operations to make the repurchases.

In 2017, we repurchased 0.9 million shares at cost of $51.0 million. In 2016, we did not repurchase any shares due to our transition to a subscription business model and the near-term impact on free cash flow and EBITDA.