Investment in Real Estate - Summary Regarding Industrial Properties Included in Discontinued Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Real Estate Investment Property, Net [Abstract]
Total Revenues									$ 10,955	$ 21,649	$ 32,079
Property Expenses									(4,450)	(8,879)	(12,947)
Impairment of Real Estate									(1,605)	(1,438)	(6,214)
Depreciation and Amortization									(3,647)	(7,834)	(8,505)
Interest Expense									0	0	(63)
Gain on Sale of Real Estate									34,344	12,665	20,419
Provision for Income Taxes									0	0	(1,246)
Income from Discontinued Operations	$ 19,323	$ 5,919	$ 12,639	$ (2,284)	$ 1,164	$ 5,869	$ 3,141	$ 5,989	$ 35,597	$ 16,163	$ 23,523