Financial Information for Operation Segments (Parenthetical) (Detail) (Home Sales and Rentals Operations segment, USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Home Sales and Rentals Operations segment
Segment Reporting Information [Line Items]
Site rental income	$ 9,316	$ 6,174	$ 26,126	$ 15,988