Investment in Real Estate - Summary Regarding Industrial Properties Included in Discontinued Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Investment in Real Estate [Abstract]
Total Revenues	$ 249	$ 3,249	$ 2,752	$ 12,087
Property Expenses	26	(1,273)	(1,032)	(4,920)
Impairment of Real Estate	0	0	(176)	(1,503)
Depreciation and Amortization	(59)	(1,010)	(816)	(3,927)
Gain on Sale of Real Estate	5,243	4,420	15,650	12,005
Income from Discontinued Operations	$ 5,459	$ 5,386	$ 16,378	$ 13,742

Amount of gain (loss), before tax expense or benefit and not previously recognized, resulting from the sale of a business component.

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Amount of income (loss) from a disposal group, net of income tax before extraordinary items allocable to noncontrolling interests. Includes, net of tax, income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.

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