Investment in Real Estate - Additional Information (Detail) (USD $)	12 Months Ended						1 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	May 31, 2011	Dec. 31, 2012 R V Resort [Member] integer	Apr. 21, 2010 R V Resort [Member] integer	Jan. 31, 2010 Creekside integer	Dec. 31, 2012 Purchase Price Allocation Adjustments	Dec. 31, 2012 R V Resort [Member] integer
Real Estate Properties [Line Items]
Asset acquisition price adjustments period								1 year
Number of acquired properties					2	4
Location							Wyoming, Michigan		Snoqualmie, Washington
Number of acquired sites	1,765	30,129				573
Purchase price	$ 25,000,000	$ 1,500,000,000		$ 1,430,000,000		$ 2,500,000
Number of Sites Disposed							165		163
Gain (Loss) on Sale of Property Plant Equipment	4,600,000
Proceeds from Sale of Property, Plant, and Equipment	7,600,000
Debt Instrument, Debt Default, Amount			3,600,000
Mortgage debt assumed to acquire properties	816,000	556,000,000
Gain (Loss) on disposition of assets							200,000
Proceeds from sale of property	$ 7,564,000	$ 252,000	$ 0
Number of closed acquisition properties		75