Financial Information for Operation Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenues:
Community base rental income	$ 105,813	$ 102,954
Gross revenue from home sales	2,839	2,060
Resort base rental income	40,739	37,579
Brokered resale revenues, net	1,796	1,746
Right-to-use annual payments	11,523	11,751
Rental home income	4,165	3,043
Right-to-use contracts current period, gross	2,831	2,244
Right-to-use contracts current period, deferred	(1,040)	(607)
Utility income and other	17,165	16,403
Total revenues	190,588	181,291
Expenses:
Property operating and maintenance	56,674	54,442
Cost of home sales	2,960	2,216
Real estate taxes	12,917	12,522
Home selling expenses	527	333
Sales and marketing, gross	2,361	1,643
Rental home operating and maintenance	2,187	1,605
Sales and marketing, deferred commissions, net	(463)	(242)
Property management	10,249	9,751
Total expenses	151,654	164,401
Income from operations	38,934	16,890
Property Operations segment
Revenues:
Community base rental income	105,813	102,954
Resort base rental income	40,739	37,579
Right-to-use annual payments	11,523	11,751
Right-to-use contracts current period, gross	2,831	2,244
Right-to-use contracts current period, deferred	(1,040)	(607)
Utility income and other	17,165	16,403
Ancillary services revenues, net	1,478	1,417
Total revenues	178,509	171,741
Expenses:
Property operating and maintenance	56,674	54,442
Real estate taxes	12,917	12,522
Sales and marketing, gross	2,361	1,643
Sales and marketing, deferred commissions, net	(463)	(242)
Property management	10,249	9,751
Total expenses	81,738	78,116
Income from operations	96,771	93,625
Home Sales and Rentals Operations segment
Revenues:
Gross revenue from home sales	2,839	2,060
Brokered resale revenues, net	318	329
Rental home income	4,165	3,043
Total revenues	7,322	5,432
Expenses:
Cost of home sales	2,960	2,216
Home selling expenses	527	333
Rental home operating and maintenance	2,187	1,605
Total expenses	5,674	4,154
Income from operations	$ 1,648	$ 1,278