Derivative Financial Instruments - Fair Values of Outstanding Zero Cost Collar Recorded as Liabilities (Detail) - Zero Cost Collars [Member] $ in Thousands	Dec. 31, 2015 USD ($)
Liabilities Derivatives:
Derivatives designated as hedging instruments, Liability	$ 40
Other Current Liabilities [Member]
Liabilities Derivatives:
Derivatives designated as hedging instruments, Liability	$ 40