Debt (Narrative) (Detail) € in Millions, $ in Millions	Sep. 27, 2019 USD ($) loan	Sep. 27, 2019 EUR (€) loan	May 15, 2018 USD ($)
Uncommitted Revolving Credit Facilities $75 million [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 75.0
Number Of Revolving Loan Facilities | loan	2	2
Uncommitted Revolving Credit Facilities 100 million euros [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity | €		€ 100.0
Number Of Revolving Loan Facilities | loan	1	1
JPMorgan Chase Bank, N.A. [Member] | Revolving Credit Facility | Unsecured Debt [Member] | 2018 Credit Facility
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity			$ 1,750.0
JPMorgan Chase Bank, N.A. [Member] | Revolving Credit Facility, due May 2023 [Member] | Unsecured Debt [Member] | 2018 Credit Facility
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity			1,250.0
JPMorgan Chase Bank, N.A. [Member] | Delayed Draw Term Loan [Member] | Unsecured Debt [Member] | 2018 Credit Facility
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity			500.0
JPMorgan Chase Bank, N.A. [Member] | Additional Loan Facility [Member] | Unsecured Debt [Member] | 2018 Credit Facility
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity			$ 500.0