Financial Information for Operation Segments (Detail) (USD $) In Thousands, unless otherwise specified	1 Months Ended	3 Months Ended		9 Months Ended
	Jul. 17, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Gain (Loss) on Condemnation	$ 900	$ 929	$ 0	$ 929	$ 0
Extinguishment of Debt, Amount		5,087	36,530	5,087	37,911
Assets		3,451,148	3,397,130	3,451,148	3,397,130	3,392,309
Capital improvements				41,645	48,571
Revenues:
Community base rental income		106,967	103,157	319,514	305,401
Resort base rental income		44,351	39,932	126,188	113,868
Right-to-use annual payments		11,404	12,323	33,859	35,889
Right-to-use contracts current period, gross		3,944	3,707	9,956	9,899
Right-to-use contracts current period, deferred		(1,989)	(1,856)	(4,303)	(4,446)
Utility And Other Income		18,581	16,224	53,070	48,694
Gross revenue from home sales		8,717	5,415	20,455	12,328
Brokered resale revenues, net		1,124	1,395	3,491	4,122
Rental home income		3,684	3,584	11,187	10,576
Total revenues		200,554	187,966	585,992	548,493
Expenses:
Property operating and maintenance		66,105	61,782	186,018	175,183
Real estate taxes		12,263	11,584	36,905	35,873
Sales and marketing, gross		3,018	3,842	8,118	9,536
Sales and marketing, deferred commissions, net		(757)	(706)	(2,022)	(1,824)
Property management		11,086	10,077	32,169	30,380
Cost of home sales		8,156	5,137	19,679	11,837
Home selling expenses		513	563	1,710	1,544
Rental home operating and maintenance		1,829	1,950	5,376	5,307
Income from operations		28,110	(7,071)	99,509	46,806
Property Operations Segment [Member]
Segment Reporting Information [Line Items]
Assets		3,170,718	3,099,625	3,170,718	3,099,625
Capital improvements				22,111	17,787
Revenues:
Community base rental income		106,967	103,157	319,514	305,401
Resort base rental income		44,351	39,932	126,188	113,868
Right-to-use annual payments		11,404	12,323	33,859	35,889
Right-to-use contracts current period, gross		3,944	3,707	9,956	9,899
Right-to-use contracts current period, deferred		(1,989)	(1,856)	(4,303)	(4,446)
Utility And Other Income		18,581	16,224	53,070	48,694
Ancillary services revenues, net		788	1,170	2,575	3,282
Total revenues		184,046	174,657	540,859	512,587
Expenses:
Property operating and maintenance		66,105	61,782	186,018	175,183
Real estate taxes		12,263	11,584	36,905	35,873
Sales and marketing, gross		3,018	3,842	8,118	9,536
Sales and marketing, deferred commissions, net		(757)	(706)	(2,022)	(1,824)
Property management		11,086	10,077	32,169	30,380
Income from operations		92,331	88,078	279,671	263,439
Home Sales and Rentals Operations segment
Segment Reporting Information [Line Items]
Assets		280,430	297,505	280,430	297,505
Capital improvements				19,534	30,784
Revenues:
Gross revenue from home sales		8,717	5,415	20,455	12,328
Brokered resale revenues, net		336	225	916	840
Rental home income		3,684	3,584	11,187	10,576
Total revenues		12,737	9,224	32,558	23,744
Expenses:
Cost of home sales		8,156	5,137	19,679	11,837
Home selling expenses		513	563	1,710	1,544
Rental home operating and maintenance		1,829	1,950	5,376	5,307
Income from operations		$ 2,239	$ 1,574	$ 5,793	$ 5,056