Discontinued Operations and Disposition of Real Estate and Real Estate Investments - Operating Results Relating to Assets Sold or Designated as Held for Sale (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Discontinued Operations [Line Items]
Revenues	$ 9,265	$ 48,987	$ 73,152
Operating expenses	4,186	19,735	32,488
Impairment charges	21,076	57,932	87,045
Interest, net	1,961	13,194	26,669
Debt extinguishment costs, net	0	7,191	409
Depreciation and amortization	2,305	14,404	24,323
Total Expenses	29,528	112,456	170,934
Loss from discontinued operations	(20,263)	(63,469)	(97,782)
Gain on deconsolidation of interests	0	4,716	5,221
Gain (loss) on disposition of real estate, net of tax	3,847	40,163	5,775
Loss from discontinued operations	$ (16,416)	$ (18,590)	$ (86,786)