Financial Information for Operation Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Revenues:
Community base rental income	$ 103,197		$ 66,408		$ 206,151		$ 132,591
Gross revenue from home sales	1,960		1,288		4,020		2,645
Resort base rental income	30,408		29,251		67,987		65,719
Brokered resale revenues, net	489		571		2,235		2,107
Right-to-use annual payments	12,221		12,563		23,972		24,575
Rental home income	3,358		1,521		6,401		2,951
Right-to-use contracts current period, gross	2,942		4,857		5,186		8,710
Right-to-use contracts current period, deferred	(1,285)		(3,414)		(1,891)		(5,910)
Utility income and other	17,582		12,484		33,985		25,546
Total revenues	174,827		127,690		356,119		262,833
Expenses:
Property operating and maintenance	58,327		47,655		112,769		91,966
Cost of home sales	2,602		1,049		4,818		2,468
Real estate taxes	11,952		8,161		24,474		16,218
Home selling expenses	403		406		736		883
Sales and marketing, gross	2,633		3,083		4,276		5,339
Rental home operating and maintenance	1,541		838		3,146		1,667
Sales and marketing deferred commissions, net	(655)		(1,347)		(897)		(2,347)
Property management	9,427		8,193		19,178		16,656
Total expenses	169,020		116,577		333,421		226,872
Income from operations	5,807		11,113		22,698		35,961
Property Operations segment
Revenues:
Community base rental income	103,197		66,408		206,151		132,591
Resort base rental income	30,408		29,251		67,987		65,719
Right-to-use annual payments	12,221		12,563		23,972		24,575
Right-to-use contracts current period, gross	2,942		4,857		5,186		8,710
Right-to-use contracts current period, deferred	(1,285)		(3,414)		(1,891)		(5,910)
Utility income and other	17,582		12,484		33,985		25,546
Ancillary services revenues, net	157		357		1,574		1,640
Total revenues	165,222		122,506		336,964		252,871
Expenses:
Property operating and maintenance	58,327		47,655		112,769		91,966
Real estate taxes	11,952		8,161		24,474		16,218
Sales and marketing, gross	2,633		3,083		4,276		5,339
Sales and marketing deferred commissions, net	(655)		(1,347)		(897)		(2,347)
Property management	9,427		8,193		19,178		16,656
Total expenses	81,684		65,745		159,800		127,832
Income from operations	83,538		56,761		177,164		125,039
Home Sales and Rentals Operations segment
Revenues:
Gross revenue from home sales	1,960		1,288		4,020		2,645
Brokered resale revenues, net	332		214		661		467
Rental home income	3,358	[1]	1,521	[1]	6,401	[1]	2,951	[1]
Total revenues	5,650		3,023		11,082		6,063
Expenses:
Cost of home sales	2,602		1,049		4,818		2,468
Home selling expenses	403		406		736		883
Rental home operating and maintenance	1,541		838		3,146		1,667
Total expenses	4,546		2,293		8,700		5,018
Income from operations	$ 1,104		$ 730		$ 2,382		$ 1,045

[1] Does not include approximately $8.9 million and $5.1 million for the three months ended June 30, 2012 and 2011, respectively, and approximately $16.6 million and $9.8 million for the six months ended June 30, 2012 and 2011, respectively , of site rental income included in Community base rental income.