Consolidated Unaudited Pro Forma Information (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Business Acquisition, Pro Forma Information [Line Items]
Total revenue of real estate properties acquired, as reported	$ 10,039	$ 0	$ 22,042	$ 0
Pro forma rental income	45,347	42,260	133,861	122,776
Net income (loss) allocable to common shares of real estate properties acquired, as reported	846	0	1,813	0
Pro forma net income (loss) allocable to common shares	$ (22,393)	$ (14,912)	$ (59,458)	$ (166,797)
Earnings (loss) per share attributable to common shareholders of real estate properties acquired
Basic and diluted-as reported	$ 0.01	$ 0.00	$ 0.02	$ 0.00
Basic and diluted-as pro forma	$ (0.27)	$ (0.21)	$ (0.73)	$ (2.50)

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Business Acquisition Pro Forma Earnings Per Share Basic And Diluted

+ References

No definition available.

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- Definition

The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

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- Definition

The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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- Definition

This element represents the amount of earnings or loss of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

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- Definition

This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

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- Definition

The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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No definition available.

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