Segment Financial Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Revenue for Reportable Segment									$ 712,600	$ 668,776	$ 564,633
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest									75,208	61,848	40,009
Operations expenses									(355,650)	(328,472)	(287,283)
Income from segment operations									356,950	340,304	277,350
Interest income									7,770	7,689	5,641
Income from operations									254,551	206,443	176,852
Reconciliation to Net income available for Common Shares
Corporate Interest Income									490	446	283
General and administrative									(7,515)	(6,795)	(6,452)
Transaction costs									(37,844)	0	0
Interest and related amortization									(28,211)	(26,388)	(42,046)
Rent Control Initiatives Expenses and Other									(2,771)	(1,456)	(2,043)
Interest Expense, Debt									(118,522)	(123,992)	(99,489)
Equity in income of unconsolidated joint ventures									2,039	1,899	1,948
Consolidated income from continuing operations	28,713	34,936	21,786	40,470	29,015	21,492	6,298	17,654	77,247	63,747	41,957
Consolidated net income									125,905	74,459	42,504
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax									41,525	4,596	0
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax									7,133	6,116	547
Total Assets	3,391,639				3,398,226				3,391,639	3,398,226	3,496,101
Assets of Disposal Group, Including Discontinued Operation	0				119,852				0	119,852	122,328
Capital Improvements									64,714	75,260	62,032
Real Estate Depreciation Expense and Rental Homes									(108,229)	(102,083)	(83,013)
Amortization of Intangible Assets for Continuing Operations									1,940	39,467	23,126
Property Operations segment
Segment Reporting Information [Line Items]
Revenue for Reportable Segment									679,319	647,731	550,529
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest									350,524	336,037	274,945
Operations expenses									(328,795)	(311,694)	(275,584)
Income from segment operations									350,524	336,037	274,945
Interest income									3,397	3,075	3,377
Income from operations									250,607	203,999	176,801
Reconciliation to Net income available for Common Shares
Total Assets	3,096,156								3,096,156
Capital Improvements									26,430	30,863	26,224
Real Estate Depreciation Expense and Rental Homes									(101,374)	(96,419)	(78,838)
Amortization of Intangible Assets for Continuing Operations									1,940	38,694	22,683
Home Sales and Rentals Operations segment
Segment Reporting Information [Line Items]
Revenue for Reportable Segment									33,281	21,045	14,104
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest									6,426	4,267	2,405
Operations expenses									(26,855)	(16,778)	(11,699)
Income from segment operations									6,426	4,267	2,405
Interest income									4,373	4,614	2,264
Income from operations									3,944	2,444	51
Reconciliation to Net income available for Common Shares
Total Assets	295,483								295,483
Capital Improvements									38,284	44,397	35,808
Real Estate Depreciation Expense and Rental Homes									(6,855)	(5,664)	(4,175)
Amortization of Intangible Assets for Continuing Operations									0	773	443
Maximum
Segment Reporting Information [Line Items]
Number of Reportable Segments									2
Continuing Operations [Member]
Reconciliation to Net income available for Common Shares
Total Assets					3,278,374					3,278,374	3,373,773
Continuing Operations [Member] | Property Operations segment
Reconciliation to Net income available for Common Shares
Total Assets					2,984,766					2,984,766	3,172,222
Continuing Operations [Member] | Home Sales and Rentals Operations segment
Reconciliation to Net income available for Common Shares
Total Assets					$ 293,608					$ 293,608	$ 201,551