Financial Instruments and Fair Value Measurements - Foreign Currency Contracts Activity (Detail) - Forwards [Member] - Net Investment Hedges [Member] - Designated As Hedging Instrument [Member]	9 Months Ended
	Sep. 30, 2021 USD ($) Derivative	Sep. 30, 2020 USD ($) Derivative
Derivative [Line Items]
Notional amounts at January 1	$ 512,000,000	$ 484,000,000
New contracts	835,000,000	622,000,000
Matured, expired or settled contracts	(299,000,000)	(624,000,000)
Notional amounts at September 30	$ 1,048,000,000	$ 482,000,000
Weighted average forward rate at September 30	0	0
Active contracts at September 30 | Derivative	0	0
CAD
Derivative [Line Items]
Notional amounts at January 1	$ 377,000,000	$ 97,000,000
New contracts	535,000,000	298,000,000
Matured, expired or settled contracts	(299,000,000)	(48,000,000)
Notional amounts at September 30	$ 613,000,000	$ 347,000,000
Weighted average forward rate at September 30	1.26	1.32
Active contracts at September 30 | Derivative	7	6
GBP
Derivative [Line Items]
Notional amounts at January 1	$ 135,000,000	$ 387,000,000
New contracts	300,000,000	324,000,000
Matured, expired or settled contracts	0	(576,000,000)
Notional amounts at September 30	$ 435,000,000	$ 135,000,000
Weighted average forward rate at September 30	1.38	1.35
Active contracts at September 30 | Derivative	4	1