Debt - 3.375% Senior Unsecured Notes Due 2028 - Additional Information (Detail) - 3.375% Senior Unsecured Notes due 2030 [Member] - GBP (£)			6 Months Ended
	Mar. 26, 2021	Mar. 24, 2021	Jun. 30, 2022		Dec. 31, 2021	[1]
Debt Instrument [Line Items]
Senior unsecured notes face amount		£ 350,000,000
Percentage of par value on senior notes		99.448%
Senior unsecured notes, payable term			interest on the notes is payable annually on April 24 of each year, commencing on April 24, 2022.
Debt instrument maturity date	Apr. 24, 2030	Apr. 24, 2030
Senior unsecured notes, interest rate	3.375%	3.375%	3.375%	[1]	3.375%

[1] Non-U.S. dollar denominated debt reflects the exchange rate at June 30, 2022 and December 31, 2021.