Acquisitions - Narrative (Details) $ / shares in Units, $ in Millions			3 Months Ended			6 Months Ended		12 Months Ended
	Jul. 02, 2024 USD ($)	Sep. 26, 2023 USD ($) ft² $ / shares	Sep. 30, 2024 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Business Acquisition [Line Items]
Selling, general and administrative				$ 553.8	$ 548.0	$ 1,135.3	$ 1,153.0
Goodwill				6,227.4		6,227.4		$ 6,219.2
Net income				(583.6)	(593.3)	(977.0)	(980.9)
Cost of sales, excluding amortization and impairment of acquired intangible assets				546.0	$ 592.7	1,088.2	$ 1,255.5
Forecast
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross, Outstanding Equity Awards			$ 983.9
Reata Pharmaceuticals, Inc
Business Acquisition [Line Items]
Price per share | $ / shares		$ 172.50
Consideration transferred		$ 7,193.4
Total transaction value		6,602.9
Selling, general and administrative		196.4
Research and development expense asset acquired		197.0
Operating expenses		393.4
Inventory		1,300.0		1,259.0		1,259.0
Operating lease liabilities		151.8		151.8		151.8
Operating lease assets		$ 121.2		121.2		121.2
Lease term		16 years
Operating Lease Area | ft²		327,400
Lessee, Operating Lease, Remaining Lease Term		15 years
Fair Value Indefinite Lived Intangible Assets Discount Rate		14.30%
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory Amortization Period		3 years
Goodwill		$ 473.5		473.5		473.5
Business Combination, Consideration Transferred, Equity Compensation Pre-acquisition Services		590.5
Reata Pharmaceuticals, Inc | Fair Value Adjustment to Inventory
Business Acquisition [Line Items]
Net income				90.1		134.2
Reata Pharmaceuticals, Inc | Clinical Inventory | Fair Value Adjustment to Inventory
Business Acquisition [Line Items]
Cost of sales, excluding amortization and impairment of acquired intangible assets				46.0
Reata Pharmaceuticals, Inc | Secured Debt | The Credit Facility | Line of Credit
Business Acquisition [Line Items]
Long-term debt, gross		1,000.0
Reata Pharmaceuticals, Inc | Selling, general and administrative
Business Acquisition [Line Items]
Business Combination, Separately Recognized Transactions, Additional Disclosures, Acquisition Cost Expensed								$ 28.4
Reata Pharmaceuticals, Inc | Completed technology for SKYCLARYS (U.S.)
Business Acquisition [Line Items]
Intangible assets:		4,200.0		4,200.0		4,200.0
Reata Pharmaceuticals, Inc | In-process research and development
Business Acquisition [Line Items]
Intangible assets:		2,300.0		2,300.0		2,300.0
Reata Pharmaceuticals, Inc | Priority review voucher
Business Acquisition [Line Items]
Intangible assets:		100.0		100.0		100.0
Reata Pharmaceuticals, Inc | Other clinical programs
Business Acquisition [Line Items]
Intangible assets:		$ 40.0		$ 40.0		$ 40.0
Human Immunology Biosciences | Subsequent Event
Business Acquisition [Line Items]
Consideration transferred	$ 1,150.0
Contingent consideration obligations	$ 650.0