Fair Value Measurements - Cash and Cash Equivalents (Details) $ in Millions	6 Months Ended
	Mar. 30, 2024 USD ($)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cost	$ 2,179.9
Unrealized Gains	0.1
Unrealized Losses	0.0
Fair Value	2,180.0
Cash and Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	2,180.0
Cash
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cost	1,371.9
Unrealized Gains	0.0
Unrealized Losses	0.0
Fair Value	1,371.9
Cash | Cash and Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	1,371.9
Money Market Funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cost	410.2
Unrealized Gains	0.0
Unrealized Losses	0.0
Fair Value	410.2
Money Market Funds | Cash and Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	410.2
US Treasury Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cost	348.0
Unrealized Gains	0.1
Unrealized Losses	0.0
Fair Value	348.1
US Treasury Securities | Cash and Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	348.1
Commercial Paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cost	49.8
Unrealized Gains	0.0
Unrealized Losses	0.0
Fair Value	49.8
Commercial Paper | Cash and Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	$ 49.8