Unaudited Pro Forma Consolidated Results of Operations (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Business Acquisition, Pro Forma Information [Line Items]
Total revenues	$ 174,827	[1]	$ 167,116	[1]	$ 356,119	[1]	$ 341,440	[1]
Net income available for Common Shares	$ 18,858	[1]	$ 3,471	[1]	$ 48,049	[1]	$ 17,289	[1]
Earnings per Common Share - Basic	$ 0.46	[1]	$ 0.09	[1]	$ 1.17	[1]	$ 0.43	[1]
Earnings per Common Share - Fully Diluted	$ 0.46	[1],[2]	$ 0.09	[1],[2]	$ 1.16	[1],[2]	$ 0.43	[1],[2]

[1] The following expenses, except for c. below, are not reflected in the Unaudited Pro Forma Results of Operations for the three and six months ended June 30, 2011 as they are either short-term in nature or are not reflective of the historical results of the Company or the seller: a. The Company has estimated that its annual incremental property management expenses associated with the Acquisition are approximately $5.5 million. b. The Company has estimated that its annual incremental general and administrative expenses associated with the Acquisition, including Chattel Loan servicing, are approximately $1.6 million. c. For the three and six months ended June 30, 2011, the Company has estimated the amortization expense of an intangible asset for in-place leases to be approximately $74.0 million. The estimated useful life for acquired in-place leases is one year.

[2] For the three and six months ended June 30, 2011, the Company's weighted average of approximately 4.6 million common OP units (which were dilutive to the Company's historical operations) were anti-dilutive, and therefore are excluded from the computation of the Pro Forma Earnings per Common Share - Fully Diluted.