Financial Instruments and Fair Value Measurements - Foreign Currency Contracts Activity (Detail) - Forwards [Member] - Net Investment Hedges [Member] - Designated As Hedging Instrument [Member]	6 Months Ended
	Jun. 30, 2021 USD ($) Derivative	Jun. 30, 2020 USD ($) Derivative
Derivative [Line Items]
Notional amounts at January 1	$ 512,000,000	$ 484,000,000
New contracts	719,000,000	324,000,000
Matured, expired or settled contracts	(125,000,000)	(576,000,000)
Notional amounts at June 30	$ 1,106,000,000	$ 232,000,000
Weighted average forward rate at June 30	0	0
Active contracts at June 30 | Derivative	0	0
CAD
Derivative [Line Items]
Notional amounts at January 1	$ 377,000,000	$ 97,000,000
New contracts	419,000,000	0
Matured, expired or settled contracts	(125,000,000)	0
Notional amounts at June 30	$ 671,000,000	$ 97,000,000
Weighted average forward rate at June 30	1.27	1.32
Active contracts at June 30 | Derivative	8	2
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 June 30	$ 435,000,000	$ 135,000,000
Weighted average forward rate at June 30	1.38	1.35
Active contracts at June 30 | Derivative	4	1