Fair Value (Tables)

3 Months Ended

Dec. 29, 2017

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 December 29, 2017								As of September 29, 2017
			Fair Value Measurements								Fair Value Measurements
	Total		Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3
Assets
Money market funds	$	629.2	$	629.2	$	—	$	—	$	592.6	$	592.6	$	—	$	—
Total	$	629.2	$	629.2	$	—	$	—	$	592.6	$	592.6	$	—	$	—
Liabilities
Contingent consideration liability recorded for business combinations	$	11.9	$	—	$	—	$	11.9	$	11.9	$	—	$	—	$	11.9
Total	$	11.9	$	—	$	—	$	11.9	$	11.9	$	—	$	—	$	11.9