Financial Instruments and Fair Value Measurements - Foreign Currency Contracts Activity (Detail) - Forwards [Member] - Net Investment Hedges [Member] - Designated As Hedging Instrument [Member]	12 Months Ended
	Dec. 31, 2020 USD ($) Derivative	Dec. 31, 2019 USD ($) Derivative	Dec. 31, 2018 USD ($) Derivative
Derivative [Line Items]
Notional amounts at January 1	$ 484,000,000	$ 687,000,000	$ 99,000,000
New contracts	836,000,000	1,655,000,000	2,848,000,000
Matured, expired or settled contracts	(808,000,000)	(1,858,000,000)	(2,260,000,000)
Notional amounts at December 31	512,000,000	484,000,000	687,000,000
CAD
Derivative [Line Items]
Notional amounts at January 1	97,000,000	100,000,000	99,000,000
New contracts	377,000,000	97,000,000	100,000,000
Matured, expired or settled contracts	(97,000,000)	(100,000,000)	(99,000,000)
Notional amounts at December 31	$ 377,000,000	$ 97,000,000	$ 100,000,000
Weighted average forward rate at December 31	1.31	1.32	1.28
Active contracts at December 31 | Derivative	6	2	2
BRL
Derivative [Line Items]
Notional amounts at January 1	$ 0	$ 460,000,000	$ 0
New contracts		489,000,000	1,568,000,000
Matured, expired or settled contracts		(949,000,000)	(1,108,000,000)
Notional amounts at December 31		$ 0	$ 460,000,000
Weighted average forward rate at December 31			3.91
Active contracts at December 31 | Derivative		0	1
GBP
Derivative [Line Items]
Notional amounts at January 1	387,000,000	$ 127,000,000	$ 0
New contracts	459,000,000	649,000,000	127,000,000
Matured, expired or settled contracts	(711,000,000)	(389,000,000)	0
Notional amounts at December 31	$ 135,000,000	$ 387,000,000	$ 127,000,000
Weighted average forward rate at December 31	1.35	1.29	1.28
Active contracts at December 31 | Derivative	1	5	2
EUR
Derivative [Line Items]
Notional amounts at January 1	$ 0	$ 0	$ 0
New contracts		420,000,000	1,053,000,000
Matured, expired or settled contracts		(420,000,000)	(1,053,000,000)
Notional amounts at December 31		$ 0	$ 0
Active contracts at December 31 | Derivative		0	0