Real Estate Activities - Summary of Revenue and Expense Information for 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
Real Estate [Abstract]
Real estate revenue	$ 1,427	$ 7,027	$ 6,221	$ 21,048
Expenses:
Operating expenses	(443)	(2,983)	(2,170)	(9,521)
Depreciation and amortization	(62)	(1,858)	(216)	(5,662)
Interest expense	(494)	(1,101)	(1,753)	(3,031)
Total expenses	(999)	(5,942)	(4,139)	(18,214)
Operating results from discontinued operations	428	1,085	2,082	2,834
Gains on sales of discontinued operations	45,097	0	78,351	0
Income from discontinued operations	$ 45,525	$ 1,085	$ 80,433	$ 2,834