Derivatives - Summary of Impact of Derivatives in Cash Flow Hedging Relationships on Statement of Operations and Statement of OCI (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative [Line Items]
Amortization Reclassified from OCI into Income (Loss)	$ 609	$ 579	$ 1,792	$ 1,690
Interest Expense [Member]
Derivative [Line Items]
Amortization Reclassified from OCI into Income (Loss)	$ (609)	$ (579)	$ (1,792)	$ (1,690)