Derivative Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($)		Mar. 31, 2018		Dec. 31, 2017
Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Nominal volume	[1]			$ 66,600,000
Derivative asset	[1]			400,000
Derivative liability	[1]			1,300,000
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Nominal volume		$ 671,700,000		468,200,000
Derivative asset		4,400,000		2,400,000
Derivative liability		3,500,000		300,000
Less Than One Year | Derivatives Designated as Hedging Instruments | Foreign Exchange Forward | Cash Flow Hedging
Derivatives, Fair Value [Line Items]
Nominal volume	[1]			66,600,000
Less Than One Year | Derivatives Designated as Hedging Instruments | Foreign Exchange Forward | Cash Flow Hedging | Other current assets
Derivatives, Fair Value [Line Items]
Derivative asset	[1]			400,000
Less Than One Year | Derivatives Designated as Hedging Instruments | Foreign Exchange Forward | Cash Flow Hedging | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability	[1]			1,300,000
Less Than Six Months | Not Designated as Hedging Instrument | Foreign Exchange Swaps
Derivatives, Fair Value [Line Items]
Nominal volume		671,700,000	[2]	468,200,000	[3]
Less Than Six Months | Not Designated as Hedging Instrument | Foreign Exchange Swaps | Other current assets
Derivatives, Fair Value [Line Items]
Derivative asset		4,400,000	[4]	2,400,000	[5]
Less Than Six Months | Not Designated as Hedging Instrument | Foreign Exchange Swaps | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability		$ 3,500,000	[6]	$ 300,000	[7]

[1] There is no netting since there are no offsetting contracts.

[2] Net nominal amount after deducting for offsetting swaps under ISDA agreements is $655.4 million.

[3] Net nominal amount after deducting for offsetting swaps under ISDA agreements is $468.2 million.

[4] Net amount after deducting for offsetting swaps under ISDA agreements is $4.3 million.

[5] Net amount after deducting for offsetting swaps under ISDA agreements is $2.4 million.

[6] Net amount after deducting for offsetting swaps under ISDA agreements is $3.4 million.

[7] Net amount after deducting for offsetting swaps under ISDA agreements is $0.3 million.