Financial Instruments and Fair Value Measurements - Summary of Activity in Interest Rate Swaps (Detail) - Interest Rate Swaps [Member] - USD ($)		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017
CAD
Derivative [Line Items]
Notional amounts at January 1		$ 271,000,000	$ 271,000,000
New contracts	[1]	0	0
Matured, expired or settled contracts	[2]	(271,000,000)	0
Notional amounts at June 30		0	$ 271,000,000
EUR
Derivative [Line Items]
Notional amounts at January 1		0
New contracts	[1]	500,000,000
Matured, expired or settled contracts	[2]	0
Notional amounts at June 30		500,000,000
USD
Derivative [Line Items]
Notional amounts at January 1		0
New contracts	[1]	300,000,000
Matured, expired or settled contracts	[2]	(300,000,000)
Notional amounts at June 30		$ 0

[1] During the six months ended June 30, 2018, we entered into two interest rate swap contracts with an aggregated notional amount of €400.0 million ($499.7 million) to effectively fix the interest rate on our senior notes bearing a floating rate of Euribor plus 0.25% issued in January 2018.

[2] During the six months ended June 30, 2018, we repaid CAD 201.4 million ($158.9 million) on our 2015 Canadian Term Loan, leaving CAD 170.5 million ($128.7 million at June 30, 2018) outstanding. At that time, we settled the interest rate swap contracts related to the 2015 Canadian Term Loan as we determined at that time it was no longer probable that we would continue to have the future cash flows as originally hedged. As a result, the $12.5 million gain in Accumulated Other Comprehensive Income (Loss) “AOCI/L” at the time of settlement was reclassified to Interest Expense during the first quarter of 2018.