Financial Instruments and Fair Value Measurements - Summary of Activity in Interest Rate Swaps (Detail) - Interest Rate Swaps [Member] - Cash Flow Hedges [Member] - Designated As Hedging Instrument [Member] - USD ($)	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
EUR
Derivative [Line Items]
Notional amounts at January 1	$ 500,000,000	$ 0
New contracts	0	500,000,000
Matured, expired or settled contracts	0	0
Notional amounts at June 30	$ 500,000,000	500,000,000
CAD
Derivative [Line Items]
Notional amounts at January 1		271,000,000
New contracts		0
Matured, expired or settled contracts		(271,000,000)
Notional amounts at June 30		0
USD
Derivative [Line Items]
Notional amounts at January 1		0
New contracts		300,000,000
Matured, expired or settled contracts		(300,000,000)
Notional amounts at June 30		$ 0