Borrowing Arrangements - Additional Information (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015 USD ($) Property integer Rate	Sep. 29, 2015 USD ($)	Sep. 30, 2014 USD ($)	Mar. 25, 2015	Dec. 31, 2014 USD ($) Property
Debt Instrument [Line Items]
Mortgage notes payable	$ 1,956,246				$ 2,012,246
Weighted average interest rate | Rate	5.00%
Stated interest rate, minimum | Rate	3.45%
Stated interest rate, maximum | Rate	8.87%
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		$ 169,000
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	5.73%			5.58%
Number of pledged properties | Property	32
Repayments of long-term debt	$ 48,700	$ 370,200
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
Variable rate in addition to LIBOR rate | Rate	1.20%
Interest rate during period | Rate	0.20%
Minimum | Old Credit Facilities
Debt Instrument [Line Items]
Debt instrument maturity year	2015
Maximum
Debt Instrument [Line Items]
Debt instrument maturity year	2040
Variable rate in addition to LIBOR rate | Rate	1.65%
Interest rate during period | Rate	0.35%
Maximum | Old Credit Facilities
Debt Instrument [Line Items]
Debt instrument maturity year	2016
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