Investment in Real Estate - Summary Regarding Industrial Properties Included in Discontinued Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Investment in Real Estate [Abstract]
Total Revenues	$ 595	$ 3,395	$ 1,637	$ 7,345
Property Expenses	(282)	(1,509)	(703)	(3,287)
Impairment of Real Estate	(176)	0	(176)	(1,082)
Depreciation and Amortization	(81)	(937)	(528)	(2,281)
Gain on Sale of Real Estate	13,481	1,415	10,407	7,614
Income from Discontinued Operations	$ 13,537	$ 2,364	$ 10,637	$ 8,309

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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