Business Combinations Acquisitions (Details) - USD ($)								3 Months Ended						9 Months Ended
	Jul. 21, 2020	May 18, 2020	Jan. 10, 2020	Sep. 03, 2019	Aug. 02, 2019	Apr. 01, 2019	Oct. 01, 2018	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2020	Jun. 30, 2019
Business Acquisition, Contingent Consideration [Line Items]
Payments to Acquire Businesses, Gross							$ 17,100,000							$ (20,600,000)	$ (175,800,000)
Goodwill								$ 1,816,900,000			$ 1,800,900,000			1,816,900,000
Prepaid Royalties										$ 22,000,000.0
Special charges								9,500,000				$ 6,200,000		26,100,000	17,700,000
Gain (Loss) on Disposition of Other Assets								3.9			$ 15,900,000			4.2
Business Exit Costs					$ 4.0
BreatheAcquisition [Member]
Business Acquisition, Contingent Consideration [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables				$ 300,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory				6,300,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other				100,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment				2,100,000
Goodwill				60,200,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financial Assets				200,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable				(500,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other				(1,600,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities				(800,000)
Payments to Acquire Businesses, Net of Cash Acquired				127,600,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities				900,000
Voalte [Member]
Business Acquisition, Contingent Consideration [Line Items]
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability									$ 8.4					8.4
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High						$ 15,000,000.0
Payments to Acquire Businesses, Gross						175,800,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables						5,800,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory						100,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other						2,700,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment						200,000
Goodwill						98,500,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable						(1,700,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Deferred Revenue						(10,700,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other						(4,300,000)
Business Combination, Contingent Consideration, Liability						5,200,000
Payments to Acquire Businesses, Net of Cash Acquired						181,000,000.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities						(9,800,000)
Excel [Member]
Business Acquisition, Contingent Consideration [Line Items]
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability			$ 1,600,000					500,000						700,000
Contingent Consideration Classified as Equity, Fair Value Disclosure			4,500,000
Business Combination, Integration Related Costs								600,000						1.4
Excel Medical
Business Acquisition, Contingent Consideration [Line Items]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High			15,000,000.0
Payments to Acquire Businesses, Gross			13,100,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables			600,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory			900,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other			100,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment			100,000
Goodwill			9,800,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other			(2,700,000)
Business Combination, Contingent Consideration, Liability			6,100,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities			(500,000)
Payments to Acquire Businesses, Net of Cash Acquired			19,200,000
Breathe [Member]
Business Acquisition, Contingent Consideration [Line Items]
Business Combination, Integration Related Costs								0.5						2.0
Special charges								$ 0.4						$ 2.7
Connecta [Member]
Business Acquisition, Contingent Consideration [Line Items]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High		$ 4,000,000.0
Payments to Acquire Businesses, Gross		7,500,000
Goodwill		4,800,000
Business Combination, Contingent Consideration, Liability		200,000
Payments to Acquire Businesses, Net of Cash Acquired		7,700,000
Business Combination, Integration Related Costs															$ 300,000
Business Combination, Contingent Consideration Arrangements, milestone achievement, years								3 years 6 months
Noncompete Agreements [Member] | Voalte [Member]
Business Acquisition, Contingent Consideration [Line Items]
Intangible Assets						2,700,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life											5 years
Trade Names [Member] | BreatheAcquisition [Member]
Business Acquisition, Contingent Consideration [Line Items]
Intangible Assets				4,000,000.0
Trade Names [Member] | Voalte [Member]
Business Acquisition, Contingent Consideration [Line Items]
Intangible Assets						13,500,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life											10 years
Trade Names [Member] | Breathe [Member]
Business Acquisition, Contingent Consideration [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life													2 years
Customer Relationships [Member] | Voalte [Member]
Business Acquisition, Contingent Consideration [Line Items]
Intangible Assets						29,000,000.0
Customer Relationships [Member] | Breathe [Member]
Business Acquisition, Contingent Consideration [Line Items]
Intangible Assets				400,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life										8 years
Developed Technology Rights [Member] | BreatheAcquisition [Member]
Business Acquisition, Contingent Consideration [Line Items]
Intangible Assets				$ 56,000,000.0
Developed Technology Rights [Member] | Voalte [Member]
Business Acquisition, Contingent Consideration [Line Items]
Intangible Assets						$ 55,000,000.0
Developed Technology Rights [Member] | Excel Medical
Business Acquisition, Contingent Consideration [Line Items]
Intangible Assets			$ 10,900,000
Developed Technology Rights [Member] | Connecta [Member]
Business Acquisition, Contingent Consideration [Line Items]
Intangible Assets		$ 2,900,000
Technology-Based Intangible Assets [Member] | Voalte [Member]
Business Acquisition, Contingent Consideration [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life											8 years
Technology-Based Intangible Assets [Member] | Excel [Member]
Business Acquisition, Contingent Consideration [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life								5 years
Technology-Based Intangible Assets [Member] | Breathe [Member]
Business Acquisition, Contingent Consideration [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life										11 years
Technology-Based Intangible Assets [Member] | Connecta [Member]
Business Acquisition, Contingent Consideration [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		10 years
Customer-Related Intangible Assets | Voalte [Member]
Business Acquisition, Contingent Consideration [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life											10 years
Videomed [Member] | Videomed [Member]
Business Acquisition, Contingent Consideration [Line Items]
Payments to Acquire Businesses, Gross	$ 9,400,000
Business Combination, Contingent Consideration, Liability	$ 3,700,000