Financial Instruments - Derivative Instruments Designated as Cash Flow and Net Investment Hedging Instruments-additional information (Detail) (Derivatives in Cash Flow Hedging Relationships [Member], USD $)	3 Months Ended
	Mar. 31, 2015
Cross currency swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instrument maturity period (years)	10 years
Interest rate swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Senior Notes	300,000,000