Business Combinations	12 Months Ended
Sep. 28, 2018
Business Combinations [Abstract]
Business Combinations	BUSINESS COMBINATIONS Sirtex On January 30, 2018, the Company signed an agreement to acquire Sirtex Medical Limited ("Sirtex"), an Australian company that was listed on the Australian Securities Exchange, for A$28 per share or approximately A$1.6 billion. On May 4, 2018, Sirtex received an unsolicited non-binding, indicative and conditional proposal from CDH Investments ("CDH"), a China-based alternative asset manager, for the acquisition of all of the issued shares in Sirtex for A$33.60 per share. On June 14, 2018, the Company received notification from Sirtex that it had accepted the proposal from CDH. Consequently, Sirtex terminated its agreement with the Company and the Company received a net $9.0 million breakup fee from Sirtex. Business Combinations in Fiscal Year 2018 During fiscal year 2018, the Company acquired four companies, including two privately-held software companies, a distributor of radiotherapy equipment, and a manufacturer of a surface-guided radiation therapy positioning and motion management system, for an aggregate purchase price of $109.0 million. The purchase price of all four acquisitions primarily consisted of $72.1 million in goodwill and $49.9 million in finite-lived intangible assets. The Company has integrated these four acquisitions into its Oncology Systems reporting unit. Business Combinations in Fiscal Year 2017 The Company did not have any business combinations in fiscal year 2017. Business Combination in Fiscal Year 2016 During fiscal year 2016, the Company purchased a privately-held distributor of radiotherapy equipment for an aggregate purchase price of $35.2 million. The purchase price primarily consisted of $24.9 million in finite-lived intangible assets and $11.4 million in goodwill. The Company integrated the acquired business into its Oncology Systems reporting unit. Other information The excess of purchase price over the fair value amounts assigned to the assets acquired and liabilities assumed represents the goodwill amount resulting from the completed acquisitions above. The Company believes the factors that contributed to goodwill include synergies that are specific to the Company's completed acquisitions and not available to market participants and the acquisition of a talented workforce. Of the goodwill acquired in fiscal year 2018, $14.0 million is deductible for income tax purposes. In fiscal year 2016, the goodwill acquired was not deductible for income tax purposes. The fair value of assets acquired and liabilities assumed has been determined on a preliminary basis for acquisitions completed in fiscal year 2018, and the Company will finalize these amounts as it obtains the information necessary to complete the measurement process. Any changes resulting from facts and circumstances that existed as of the date of the acquisitions may result in adjustments to the amounts of goodwill, intangible assets and deferred revenue balances recorded. The Company expects to finalize these amounts no later than one year from the date of each acquisition. Management applied significant judgment in determining the fair value of intangible assets, which involved the use of significant estimates and assumptions with respect to the revenue growth rates, the economic lives, and the discount rate. The consolidated financial statements include the operating results from the date of acquisition. The impact of the completed acquisitions to the periods presented was not material. Pro forma results of operations for the completed acquisitions have not been presented because the effects of the acquisitions, individually and in the aggregate, were not material to the Company's consolidated financial statements. During fiscal years 2018, 2017 and 2016, the Company incurred acquisition-related expenses of $36.4 million, $1.9 million and $3.1 million, respectively. In 2018, acquisition-related expenses included a $29.7 million loss related to hedging the anticipated Australian dollar purchase price for Sirtex, $15.7 million acquisitions costs, partially offset by a $9.0 million breakup fee received from Sirtex in connection with the termination of the acquisition. See Note 9, "Derivative Instruments and Hedging Activities" for more information on the hedging losses.

BUSINESS COMBINATIONS

Sirtex

On January 30, 2018, the Company signed an agreement to acquire Sirtex Medical Limited ("Sirtex"), an Australian company that was listed on the Australian Securities Exchange, for A$28 per share or approximately A$1.6 billion. On May 4, 2018, Sirtex received an unsolicited non-binding, indicative and conditional proposal from CDH Investments ("CDH"), a China-based alternative asset manager, for the acquisition of all of the issued shares in Sirtex for A$33.60 per share. On June 14, 2018, the Company received notification from Sirtex that it had accepted the proposal from CDH. Consequently, Sirtex terminated its agreement with the Company and the Company received a net $9.0 million breakup fee from Sirtex.

Business Combinations in Fiscal Year 2018

During fiscal year 2018, the Company acquired four companies, including two privately-held software companies, a distributor of radiotherapy equipment, and a manufacturer of a surface-guided radiation therapy positioning and motion management system, for an aggregate purchase price of $109.0 million. The purchase price of all four acquisitions primarily consisted of $72.1 million in goodwill and $49.9 million in finite-lived intangible assets. The Company has integrated these four acquisitions into its Oncology Systems reporting unit.

Business Combinations in Fiscal Year 2017

The Company did not have any business combinations in fiscal year 2017.

Business Combination in Fiscal Year 2016

During fiscal year 2016, the Company purchased a privately-held distributor of radiotherapy equipment for an aggregate purchase price of $35.2 million. The purchase price primarily consisted of $24.9 million in finite-lived intangible assets and $11.4 million in goodwill. The Company integrated the acquired business into its Oncology Systems reporting unit.

Other information

The excess of purchase price over the fair value amounts assigned to the assets acquired and liabilities assumed represents the goodwill amount resulting from the completed acquisitions above. The Company believes the factors that contributed to goodwill include synergies that are specific to the Company's completed acquisitions and not available to market participants and the acquisition of a talented workforce. Of the goodwill acquired in fiscal year 2018, $14.0 million is deductible for income tax purposes. In fiscal year 2016, the goodwill acquired was not deductible for income tax purposes.

The fair value of assets acquired and liabilities assumed has been determined on a preliminary basis for acquisitions completed in fiscal year 2018, and the Company will finalize these amounts as it obtains the information necessary to complete the measurement process. Any changes resulting from facts and circumstances that existed as of the date of the acquisitions may result in adjustments to the amounts of goodwill, intangible assets and deferred revenue balances recorded. The Company expects to finalize these amounts no later than one year from the date of each acquisition.

Management applied significant judgment in determining the fair value of intangible assets, which involved the use of significant estimates and assumptions with respect to the revenue growth rates, the economic lives, and the discount rate.

The consolidated financial statements include the operating results from the date of acquisition. The impact of the completed acquisitions to the periods presented was not material. Pro forma results of operations for the completed acquisitions have not been presented because the effects of the acquisitions, individually and in the aggregate, were not material to the Company's consolidated financial statements.

During fiscal years 2018, 2017 and 2016, the Company incurred acquisition-related expenses of $36.4 million, $1.9 million and $3.1 million, respectively. In 2018, acquisition-related expenses included a $29.7 million loss related to hedging the anticipated Australian dollar purchase price for Sirtex, $15.7 million acquisitions costs, partially offset by a $9.0 million breakup fee received from Sirtex in connection with the termination of the acquisition. See Note 9, "Derivative Instruments and Hedging Activities" for more information on the hedging losses.