Combined Results of Operations of Properties Held for Sale or Disposed (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Rental income	$ 3,400,000	$ 3,300,000	$ 2,500,000
Utility and other income	63,800,000	62,470,000	53,116,000
Property operating expenses	(229,897,000)	(220,415,000)	(197,781,000)
Income from operations	254,551,000	206,443,000	176,852,000
Income from home sales operations	17,871,000	8,230,000	6,028,000
Interest and related amortization	(118,522,000)	(123,992,000)	(99,489,000)
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax	$ 41,525,000	$ 4,596,000	$ 0