Company's Derivative Financial Instruments on Consolidated Statements of Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Amount of unrealized gain (loss) recognized in OCI (effective portion)	$ (1)	$ (173)
Amount of gain (loss) reclassified from accumulated OCI into income (effective portion)	(162)	(157)
Amount of gain (loss) recognized in income (ineffective portion and amount excluded from effectiveness testing)	230	462
Interest Rate Swaps
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Amount of unrealized gain (loss) recognized in OCI (effective portion)	(1)	(173)
Interest Rate Swaps | Interest Expense
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Amount of gain (loss) reclassified from accumulated OCI into income (effective portion)	(162)	(157)
Other derivatives instrument | changes in fair value of financial instruments and gain on OP unit redemption
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Amount of gain (loss) recognized in income (ineffective portion and amount excluded from effectiveness testing)	$ 230	$ 462