Fair Value of Financial Instruments - Gains and Losses on Derivative Instruments in Consolidated Statement of Income (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivatives Designated as Cash Flow Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)	$ 2,943	$ (1,770)	$ 4,563
Amount of Gain (Loss) Reclassified from Cumulative Other Comprehensive Loss into Income (Effective Portion)	1,085	5,699	(4,626)
Amount of Gain (Loss) Recognized in Income on Derivative (Ineffective Portion)	(122)	256	(367)
Not Designated as Hedging Instruments [Member] | Other income (expense) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	$ (366)	$ 590	$ 212