Real Estate and Lending Activities - Supplemental Pro Forma Earnings Adjusted to Exclude Acquisition-Related Costs (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Business Combinations [Abstract]
Total revenues	$ 65,518	$ 63,695	$ 196,708	$ 188,339
Net income	$ 29,366	$ 37,091	$ 89,570	$ 92,620
Net income per share/unit - diluted	$ 0.18	$ 0.25	$ 0.55	$ 0.63

The pro forma income from continuing operations before changes in accounting and extraordinary items, net of tax effect, per diluted share of common stock for a period as if the business combination or combinations had been completed at the beginning of a period.

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)

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

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- Definition

The pro forma income from continuing operations before changes in accounting and extraordinary items, net of tax effect, for the period as if the business combination or combinations had been completed at the beginning of a period.

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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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