Borrowing Arrangements - Additional Information (Detail) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 25, 2015 USD ($) Property	Jun. 30, 2015 USD ($) Property integer Rate	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($) Property
Debt Instrument [Line Items]
Mortgage notes payable		$ 1,966,517		$ 2,012,246
Weighted average interest rate | Rate		5.00%
Stated interest rate, minimum | Rate		3.50%
Stated interest rate, maximum | Rate		8.90%
Number of pledged properties | Property		127		137
Pledged assets, not separately reported		$ 2,200,000		$ 2,400,000
New mortgage notes payable financing proceeds		395,323	$ 54,000
Payments of debt extinguishment costs		$ 17,000
Number of loans | integer		2
Unsecured debt		$ 200,000		$ 200,000
Maximum borrowing capacity		400,000
Additional borrowing capacity		$ 100,000
Expiration date		Jul. 17, 2018
Commitment fee amount			$ 3,500
Line of credit facility potential term extension period		1 year
Old Credit Facilities
Debt Instrument [Line Items]
Weighted average interest rate	5.58%	5.73%
Number of pledged properties | Property	32
Repayments of long-term debt	$ 370,200	$ 48,700
New Credit Facilities
Debt Instrument [Line Items]
Weighted average interest rate	3.93%
Number of pledged properties | Property	26
New mortgage notes payable financing proceeds	$ 395,300
Debt instrument, term		21 years
Minimum
Debt Instrument [Line Items]
Debt instrument maturity year		2016
Interest rate during period | Rate		0.20%
Minimum | Old Credit Facilities
Debt Instrument [Line Items]
Debt instrument maturity year		2015
Minimum | Amended Line Of Credit Facility
Debt Instrument [Line Items]
Variable rate in addition to LIBOR rate | Rate		1.20%
Maximum
Debt Instrument [Line Items]
Debt instrument maturity year		2040
Interest rate during period | Rate		0.35%
Maximum | Old Credit Facilities
Debt Instrument [Line Items]
Debt instrument maturity year		2016
Maximum | Amended Line Of Credit Facility
Debt Instrument [Line Items]
Variable rate in addition to LIBOR rate | Rate		1.65%
Term Loans
Debt Instrument [Line Items]
Unsecured debt		$ 200,000
Maturity date		Jan. 10, 2020
Maturity years		3 years
Term Loans | Minimum
Debt Instrument [Line Items]
Variable rate in addition to LIBOR rate | Rate		1.35%
Term Loans | Maximum
Debt Instrument [Line Items]
Variable rate in addition to LIBOR rate | Rate		1.95%
Manufactured homes | Old Credit Facilities
Debt Instrument [Line Items]
Number of pledged properties | Property		1
R V Resort | Old Credit Facilities
Debt Instrument [Line Items]
Number of pledged properties | Property		3