Taxes on Earnings - Schedule of Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Millions	Sep. 29, 2017	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Deferred revenues	$ 29.6	$ 29.5
Deferred compensation	45.0	36.5
Product warranty	9.6	9.7
Inventory adjustments	11.1	8.7
Share-based compensation	17.8	22.3
Environmental reserve	3.9	3.6
Accruals and reserves	20.1	13.6
Net operating loss carryforwards	124.4	106.4
Other	29.7	37.1
Total deferred tax assets, gross	291.2	267.4
Valuation allowance	(105.8)	(79.6)
Total deferred tax assets	185.4	187.8
Tax-deductible goodwill	(27.7)	(23.2)
Property, plant and equipment	(13.6)	(14.4)
Unremitted earnings of foreign subsidiaries	(16.2)	(20.2)
Other	(8.9)	(17.7)
Total deferred tax liabilities	(66.4)	(75.5)
Net deferred tax assets	119.0	112.3
Deferred tax assets	138.8	136.8
Deferred tax liabilities (included in other long-term liabilities)	$ (19.8)	$ (24.5)