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		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Derivative [Line Items]
Amortization Reclassified from OCI into Income (Loss)	$ 598	$ 571	$ 1,183	$ 1,111
Interest Expense [Member]
Derivative [Line Items]
Amortization Reclassified from OCI into Income (Loss)	$ (598)	$ (571)	$ (1,183)	$ (1,111)