Derivative Instruments and Hedging Activities - Schedule of Pre-tax Effect of Derivative Financial Instruments on Unaudited Condensed Consolidated Statements of Comprehensive Income (Loss) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2013
Derivatives in Cash Flow Hedging Relationships:
Gain related to effective portion of derivatives recognized in accumulated other comprehensive income	$ 4,046	$ 4,718
Loss related to effective portion of derivatives reclassified from accumulated other comprehensive income to interest expense	(382)	(722)
Gain (loss) related to ineffective portion of derivatives recognized in other income (expense)