Other Balance Sheet Information - Property, Plant and Equipment (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Jun. 26, 2021	Dec. 26, 2020	Sep. 26, 2020	Jun. 26, 2021
Balance Sheet Related Disclosures [Abstract]
Equipment	$ 541.5		$ 460.7	$ 541.5
Equipment under customer usage agreements	446.0		456.8	446.0
Building and improvements	187.9		167.3	187.9
Leasehold improvements	48.0		44.3	48.0
Land	41.4		40.7	41.4
Furniture and fixtures	16.9		16.1	16.9
Finance Lease, Right-of-Use Asset, after Accumulated Amortization	8.5		0.0	8.5
Property, plant and equipment, gross	1,290.2		1,185.9	1,290.2
Less – accumulated depreciation and amortization	(739.1)		(694.4)	(739.1)
Property, plant and equipment, net	551.1		491.5	551.1
Department of defense funds received	$ 8.3			$ 19.4
Grants received from Department of defense		$ 119.3	$ 7.6

Department of defense funds received

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Gross amount at the balance sheet date of long-lived, depreciable asset that are equipment placed at customer locations for which title is not transferred to the Company's customers.

+ References

No definition available.

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Grants received from Department of defense

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Gross amount as of the balance sheet date of long-lived, depreciable assets that include manufacturing and other equipment with finite lives used to produce goods and services, and computer equipment and software.

+ References

No definition available.

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Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation of building structures held for productive use including addition, improvement, or renovation to the structure, including, but not limited to, interior masonry, interior flooring, electrical, and plumbing.

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Amount, after accumulated amortization, of right-of-use asset from finance lease.

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Amount before accumulated depreciation of equipment commonly used in offices and stores that have no permanent connection to the structure of a building or utilities. Examples include, but are not limited to, desks, chairs, tables, and bookcases.

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Amount before accumulated depletion of real estate held for productive use, excluding land held for sale.

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Amount before accumulated depreciation of additions or improvements to assets held under a lease arrangement.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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