Reportable Segments - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Segment Reporting Disclosure [Line Items]
Revenue for Reportable Segment	$ 192,289	$ 179,397
Operating Costs and Expenses	(91,508)	(84,664)
Operating Income Loss Before Depreciation And Other	100,781	94,733
Interest Income	1,906	1,778
Real Estate Depreciation Expense and Rental Homes	(27,642)	(26,020)
Amortization of Intangible Assets for Continuing Operations	(1,315)	(159)
Operating Income (Loss)	73,730	70,332
Major customers description	All revenues are from external customers and there is no customer who contributed 10% or more of our total revenues during the quarters ended March 31, 2014 or 2013.
Corporate Interest Income	791	120
Income from other investments, net	1,601	2,480
General and Administrative Expense	(5,760)	(6,711)
Interest Expense, Debt	(28,048)	(30,123)
Rent Control Initiatives Expenses and Other	(311)	(232)
Equity income from unconsolidated joint ventures	1,887	576
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax	0	3,068
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax	0	958
Consolidated net income	43,890	40,468
Total Assets	3,410,562	3,426,566	3,391,639
Capital improvements	10,000	17,037
Assets of Disposal Group, Including Discontinued Operation		119,805
Maximum [Member]
Segment Reporting Disclosure [Line Items]
Number of reportable segments	2
Property Operations Segment [Member]
Segment Reporting Disclosure [Line Items]
Revenue for Reportable Segment	183,059	172,990
Operating Costs and Expenses	(83,663)	(79,486)
Operating Income Loss Before Depreciation And Other	99,396	93,504
Interest Income	797	801
Real Estate Depreciation Expense and Rental Homes	(24,858)	(24,375)
Amortization of Intangible Assets for Continuing Operations	(1,315)	(159)
Operating Income (Loss)	74,020	69,771
Total Assets	3,118,684
Capital improvements	4,994	4,311
Home Sales And Rentals [Member]
Segment Reporting Disclosure [Line Items]
Revenue for Reportable Segment	9,230	6,407
Operating Costs and Expenses	(7,845)	(5,178)
Operating Income Loss Before Depreciation And Other	1,385	1,229
Interest Income	1,109	977
Real Estate Depreciation Expense and Rental Homes	(2,784)	(1,645)
Amortization of Intangible Assets for Continuing Operations	0	0
Operating Income (Loss)	(290)	561
Total Assets	291,878
Capital improvements	5,006	12,726
Segment, Continuing Operations [Member]
Segment Reporting Disclosure [Line Items]
Total Assets		3,306,761
Segment, Continuing Operations [Member] | Property Operations Segment [Member]
Segment Reporting Disclosure [Line Items]
Total Assets		3,012,069
Segment, Continuing Operations [Member] | Home Sales And Rentals [Member]
Segment Reporting Disclosure [Line Items]
Total Assets		$ 294,692