Schedule of Gains and Losses on Derivatives Designated as Cash Flow Hedges (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Interest rate swap contracts
Amount of gain recognized in accumulated other comprehensive income ("AOCI") on derivatives (effective portion)	$ 474	[1]	$ 368	[1]
Amount of gain reclassified from AOCI into income (effective portion)	771	[1]	1,068	[1]
Amount of gain recognized in income on derivatives (ineffective portion and amount excluded from effectiveness testing)	$ 143	[1]	$ 1	[1]

[1] Losses on derivatives reclassified from accumulated other comprehensive income ("AOCI") into income (effective portion) were included in "Interest expense" in the Consolidated Statements of Operations.