Real Estate Investments and Accumulated Depreciation - Schedule of Real Estate Investments and Accumulated Depreciation (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Building [Member]	Dec. 31, 2012 Other Buildings and Land Improvements [Member]	Dec. 31, 2012 Furniture Fixtures and Equipment [Member] Minimum [Member]	Dec. 31, 2012 Furniture Fixtures and Equipment [Member] Maximum [Member]
Real Estate and Accumulated Depreciation [Line Items]
Aggregate cost for Federal Tax purposes	$ 2,965,294
Depreciable lives (in years)			40 years	20 years	5 years	10 years
For-sale condominiums	23,281	54,845
Assets held for sale	$ 0