Taxes on Earnings - Schedule of Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Millions	Sep. 28, 2018	Sep. 29, 2017
Income Tax Disclosure [Abstract]
Deferred revenues	$ 13.2	$ 40.8
Deferred compensation	34.6	45.0
Product warranty	7.5	9.6
Inventory adjustments	7.6	11.1
Share-based compensation	13.7	17.8
Environmental reserve	2.2	3.9
Accruals and reserves	12.1	20.1
Net operating loss carryforwards	132.0	124.4
Other	24.2	29.7
Total deferred tax assets, gross	247.1	302.4
Valuation allowance	(101.6)	(105.8)
Total deferred tax assets	145.5	196.6
Tax-deductible goodwill	(31.6)	(27.7)
Property, plant and equipment	(9.4)	(13.6)
Unremitted earnings of foreign subsidiaries	(20.4)	(16.2)
Other	(13.3)	(8.9)
Total deferred tax liabilities	(74.7)	(66.4)
Deferred tax assets	102.2	147.3
Deferred tax liabilities (included in other long-term liabilities)	(31.4)	(17.1)
Net deferred tax assets	$ 70.8	$ 130.2