Debt - Summary of Debt (Parenthetical) (Detail) $ in Thousands, £ in Millions		Sep. 30, 2021 USD ($)		Sep. 30, 2021 GBP (£)		Mar. 24, 2021	Dec. 31, 2020 USD ($)		Dec. 31, 2020 GBP (£)
Debt Instrument [Line Items]
Debt		$ 10,656,337					$ 8,934,187
GBP-denominated Borrowings [Member]
Debt Instrument [Line Items]
Debt | £				£ 182					£ 121
4.000% Senior Unsecured Notes Due 2022 [Member]
Debt Instrument [Line Items]
Senior unsecured notes, interest rate	[1]	4.00%		4.00%			4.00%		4.00%
Debt	[1]	$ 579,000					$ 610,800
2.550% Senior Unsecured Notes due 2023 [Member]
Debt Instrument [Line Items]
Senior unsecured notes, interest rate	[1]	2.55%		2.55%			2.55%		2.55%
Debt	[1]	$ 538,960					$ 546,800
3.325% Senior Unsecured Notes Due 2025 [Member]
Debt Instrument [Line Items]
Senior unsecured notes, interest rate	[1]	3.325%		3.325%			3.325%		3.325%
Debt	[1]	$ 579,000					$ 610,800
2.500% Senior Unsecured Notes due 2026 [Member]
Debt Instrument [Line Items]
Senior unsecured notes, interest rate		2.50%	[1]	2.50%	[1]	2.50%	2.50%	[1]	2.50%	[1]
Debt	[1]	$ 673,700
5.250% Senior Unsecured Notes Due 2026 [Member]
Debt Instrument [Line Items]
Senior unsecured notes, interest rate		5.25%		5.25%			5.25%		5.25%
Debt		$ 500,000					$ 500,000
5.000% Senior Unsecured Notes Due 2027 [Member]
Debt Instrument [Line Items]
Senior unsecured notes, interest rate		5.00%		5.00%			5.00%		5.00%
Debt		$ 1,400,000					$ 1,400,000
3.692% Senior Unsecured Notes due 2028 [Member]
Debt Instrument [Line Items]
Senior unsecured notes, interest rate	[1]	3.692%		3.692%			3.692%		3.692%
Debt	[1]	$ 808,440					$ 820,200
4.625% Senior Unsecured Notes Due 2029 [Member]
Debt Instrument [Line Items]
Senior unsecured notes, interest rate		4.625%		4.625%			4.625%		4.625%
Debt		$ 900,000					$ 900,000
3.375% Senior Unsecured Notes due 2030 [Member]
Debt Instrument [Line Items]
Senior unsecured notes, interest rate		3.375%	[1]	3.375%	[1]	3.375%	3.375%	[1]	3.375%	[1]
Debt	[1]	$ 471,590
3.500% Senior Unsecured Notes due 2031 [Member]
Debt Instrument [Line Items]
Senior unsecured notes, interest rate		3.50%		3.50%			3.50%		3.50%
Debt		$ 1,300,000					$ 1,300,000

[1] Non-U.S. dollar denominated debt reflects the exchange rate at September 30, 2021 and December 31, 2020.