Debt - Summary of Issuances and Redemptions of Senior Notes (Detail) € in Thousands, ¥ in Thousands, £ in Thousands, $ in Thousands	1 Months Ended	9 Months Ended
	Jan. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2020 JPY (¥)	Sep. 30, 2020 EUR (€)	Sep. 30, 2020 GBP (£)	Jan. 31, 2020 EUR (€)
February 2022 – 2035 Senior Notes [Member] | EUR
Debt Instrument [Line Items]
Aggregate Principal		$ 1,485,405		€ 1,350,000
Maturity Dates		2022-02
Maturity Dates		2035-02
February 2022 – 2035 Senior Notes [Member] | EUR | Weighted Average [Member]
Debt Instrument [Line Items]
Stated Interest Rate		0.60%	0.60%	0.60%	0.60%
April 2027 – 2050 Senior Notes [Member] | USD
Debt Instrument [Line Items]
Aggregate Principal		$ 2,200,000
Maturity Dates		2027-04
Maturity Dates		2050-04
April 2027 – 2050 Senior Notes [Member] | USD | Weighted Average [Member]
Debt Instrument [Line Items]
Stated Interest Rate		2.40%	2.40%	2.40%	2.40%
February 2035 Senior Notes [Member] | GBP
Debt Instrument [Line Items]
Aggregate Principal		$ 322,490			£ 250,000
Maturity Dates		2035-02
February 2035 Senior Notes [Member] | GBP | Weighted Average [Member]
Debt Instrument [Line Items]
Stated Interest Rate		1.90%	1.90%	1.90%	1.90%
June 2027 – 2050 Senior Notes [Member] | JPY
Debt Instrument [Line Items]
Aggregate Principal		$ 386,314			£ 41,200,000
Maturity Dates		2027-06
Maturity Dates		2050-06
June 2027 – 2050 Senior Notes [Member] | JPY | Weighted Average [Member]
Debt Instrument [Line Items]
Stated Interest Rate		1.00%	1.00%	1.00%	1.00%
October 2030 – 2050 Senior Notes [Member] | USD
Debt Instrument [Line Items]
Aggregate Principal		$ 1,250,000
Maturity Dates		2030-10
Maturity Dates		2050-10
October 2030 – 2050 Senior Notes [Member] | USD | Weighted Average [Member]
Debt Instrument [Line Items]
Stated Interest Rate		1.60%	1.60%	1.60%	1.60%
September 2032 – 2040 Senior Notes [Member] | JPY
Debt Instrument [Line Items]
Aggregate Principal		$ 186,835	¥ 19,700,000
Maturity Dates		2032-09
Maturity Dates		2040-09
September 2032 – 2040 Senior Notes [Member] | JPY | Weighted Average [Member]
Debt Instrument [Line Items]
Stated Interest Rate		1.00%	1.00%	1.00%	1.00%
January 2020 Senior Notes [Member] | EUR
Debt Instrument [Line Items]
Aggregate Principal	$ 445,880					€ 400,000
Maturity Dates	2020-01
January 2020 Senior Notes [Member] | EUR | Euribor [Member]
Debt Instrument [Line Items]
Stated Interest Rate	0.00%					0.00%
May 2021 Senior Notes [Member] | EUR
Debt Instrument [Line Items]
Stated Interest Rate		1.40%	1.40%	1.40%	1.40%
Aggregate Principal		$ 783,090		€ 700,000
Maturity Dates		2021-05
January 2022 Senior Notes [Member] | EUR
Debt Instrument [Line Items]
Stated Interest Rate		3.00%	3.00%	3.00%	3.00%
Aggregate Principal		$ 238,067		€ 212,598
Maturity Dates		2022-01
January 2022 Senior Notes [Member] | JPY
Debt Instrument [Line Items]
Maturity Dates		2022-01
February 2024 Senior Notes [Member] | EUR
Debt Instrument [Line Items]
Stated Interest Rate		3.40%	3.40%	3.40%	3.40%
Aggregate Principal		$ 112,524		€ 100,486
Maturity Dates		2024-02
August 2023 Senior Notes [Member] | EUR
Debt Instrument [Line Items]
Maturity Dates		2023-08
August 2023 Senior Notes [Member] | USD
Debt Instrument [Line Items]
Stated Interest Rate		4.30%	4.30%	4.30%	4.30%
Aggregate Principal		$ 850,000
Maturity Dates		2023-08