Fair Value (Tables)

9 Months Ended

Jun. 28, 2019

Fair Value Disclosures [Abstract]

Schedule of Fair Value Assets and Liabilities Measured on Recurring Basis

Assets and liabilities recorded at fair value on a recurring basis consisted of the following (in millions):         

	As of June 28, 2019								As of September 28, 2018
			Fair Value Measurements								Fair Value Measurements
	Total		Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3
Assets
Cash and cash equivalents*	$	742.8	$	696.4	$	46.4	$	—	$	733.3	$	683.7	$	49.6	$	—
U.S. Treasury and government securities	54.4		20.3		34.1		—		65.0		15.0		50.0		—
Corporate bonds and notes	94.4		—		94.4		—		216.0		—		216.0		—
Municipal bonds	77.2		—		77.2		—		2.8		—		2.8		—
Other government securities	1.3		—		1.3		—		33.1		—		33.1		—
Total	$	970.1	$	716.7	$	253.4	$	—	$	1,050.2	$	698.7	$	351.5	$	—
Liabilities
Contingent consideration	$	—	$	—	$	—	$	—	$	3.1	$	—	$	—	$	3.1
Total	$	—	$	—	$	—	$	—	$	3.1	$	—	$	—	$	3.1

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation

The following table summarizes changes to the fair value of the Level 3 liabilities during the three and nine months ended June 28, 2019 (in millions):

	Contingent consideration
Balance as of September 28, 2018	$	3.1
Decreases to contingent consideration included in earnings	(3.1		)
Balance as of June 28, 2019	$	—