Borrowing Arrangements - Additional Information (Detail) (USD $)	6 Months Ended			6 Months Ended		6 Months Ended											6 Months Ended			1 Months Ended		1 Months Ended
	Jun. 30, 2014 Rate Property	Jun. 30, 2013	Dec. 31, 2013 Property	Jun. 30, 2014 Old Credit Facilities [Member] Property	Dec. 31, 2013 Old Credit Facilities [Member]	Jun. 30, 2014 New Credit Facilities [Member] Property	Jun. 30, 2014 Minimum [Member]	Jun. 30, 2014 Minimum [Member] Old Credit Facilities [Member] Rate	Jun. 30, 2014 Minimum [Member] New Credit Facilities [Member]	Jun. 30, 2014 Maximum [Member]	Jun. 30, 2014 Maximum [Member] Old Credit Facilities [Member] Rate	Jun. 30, 2014 Maximum [Member] New Credit Facilities [Member]	Jun. 30, 2014 Term Loans Old Credit Facilities [Member] Rate	Jun. 30, 2014 Term Loans Minimum [Member] Old Credit Facilities [Member] Rate	Jun. 30, 2014 Term Loans Maximum [Member] Old Credit Facilities [Member] Rate	Jun. 30, 2014 R V Resort [Member] New Credit Facilities [Member] Property	Jun. 30, 2014 R V Resort [Member] Minimum [Member] New Credit Facilities [Member]	Jun. 30, 2014 R V Resort [Member] Maximum [Member] New Credit Facilities [Member]	Jun. 30, 2014 Manufactured Home [Member] New Credit Facilities [Member] Property	Jul. 17, 2014 Subsequent Event [Member] Old Credit Facilities [Member]	Jul. 01, 2014 Subsequent Event [Member] Old Credit Facilities [Member] Property	Jul. 17, 2014 Subsequent Event [Member] Amended Line Of Credit Facility [Member]	Jul. 17, 2014 Subsequent Event [Member] Minimum [Member] Amended Line Of Credit Facility [Member] Rate	Jul. 17, 2014 Subsequent Event [Member] Maximum [Member] Amended Line Of Credit Facility [Member] Rate	Jul. 17, 2014 Subsequent Event [Member] Term Loans New Credit Facilities [Member] Rate	Jul. 17, 2014 Subsequent Event [Member] Term Loans Minimum [Member] New Credit Facilities [Member] Rate	Jul. 17, 2014 Subsequent Event [Member] Term Loans Maximum [Member] New Credit Facilities [Member] Rate	Jul. 17, 2014 New policy [Member] Term Loans	Jul. 17, 2014 New policy [Member] Subsequent Event [Member] Term Loans
Debt Instrument [Line Items]
Unsecured Debt	$ 200,000,000		$ 200,000,000																										$ 200,000,000
Debt Instrument, Maturity Date													Jun. 30, 2017												Jan. 10, 2020
Mortgage notes payable	1,984,727,000		1,992,368,000
Debt, Weighted Average Interest Rate	5.30%					4.54%
Debt Instrument Maturity Year							2014		2034	2038		2038					2017	2018
Debt, minimum interest rate	3.90%
Debt, maximum interest rate	8.90%
Proceeds from Issuance of Long-term Debt	54,000,000	110,000,000				54,000,000
Number of pledge properties	142		147	11		4										2			2		2
Carrying values of properties encumbered	1,985,000,000		2,378,000,000
Repayments of Long-term Debt				56,600,000																8,400,000
Debt Instrument, Interest Rate, Stated Percentage				5.63%												6.48%					5.44%
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt																13,300,000
Debt Instrument, Unamortized Discount (Premium), Net																1,000,000
Debt instrument, interest rate based on margin over LIBOR								1.40%			2.00%			1.85%	2.80%								1.20%	1.65%		1.35%	1.95%
Derivative, Fixed Interest Rate													1.11%												1.04%
Derivative, Basis Spread on Variable Rate													1.95%												1.35%
Debt Instrument, Interest Rate at Period End													3.06%												2.39%
Derivative, Maturity Years													3 years															3 years
Lines of credit, borrowing capacity				380,000,000	380,000,000																	400,000,000
Line of Credit Facility, Additional Borrowing Capacity																						100,000,000
Lines of credit, maturity date				Sep. 15, 2016																		Jul. 17, 2018
Lines of credit, extension option				1 year
Line of credit, facility rate								0.25%			0.40%												0.20%	0.35%
Line of Credit Facility, Commitment Fee Amount																						$ 3,500,000