The aggregate expense charged against earnings for continuing operations to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in continuing operations using the indirect method.

No definition available.

Segment Financial Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Revenue for Reportable Segment									$ 761,409els_RevenueforReportableSegment	$ 713,273els_RevenueforReportableSegment	$ 669,368els_RevenueforReportableSegment
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest									132,433	75,208	61,848
Operations expenses									(381,597)us-gaap_OperatingCostsAndExpenses	(356,323)us-gaap_OperatingCostsAndExpenses	(329,064)us-gaap_OperatingCostsAndExpenses
Operating Income Loss Before Depreciation And Other									379,812	356,950	340,304
Interest income									7,450els_InterestIncome	7,770els_InterestIncome	7,689els_InterestIncome
Income from operations									272,198us-gaap_OperatingIncomeLoss	254,551us-gaap_OperatingIncomeLoss	206,443us-gaap_OperatingIncomeLoss
Reconciliation to Net income available for Common Shares
Corporate Interest Income									897els_CorporateInterestIncome	490els_CorporateInterestIncome	446els_CorporateInterestIncome
General and administrative									(7,053)els_OtherRevenues	(7,515)els_OtherRevenues	(6,795)els_OtherRevenues
Transaction costs									(5,087)us-gaap_ExtinguishmentOfDebtAmount	(37,844)us-gaap_ExtinguishmentOfDebtAmount	0us-gaap_ExtinguishmentOfDebtAmount
Interest and related amortization									(27,410)us-gaap_GeneralAndAdministrativeExpense	(28,211)us-gaap_GeneralAndAdministrativeExpense	(26,388)us-gaap_GeneralAndAdministrativeExpense
Rent Control Initiatives Expenses and Other									(2,923)	(2,771)	(1,456)
Interest Expense, Debt									(112,295)us-gaap_InterestExpenseDebt	(118,522)us-gaap_InterestExpenseDebt	(123,992)us-gaap_InterestExpenseDebt
Equity in income of unconsolidated joint ventures									4,578	2,039	1,899
Consolidated income from continuing operations	34,262	30,276	30,040	43,890	28,713	34,936	21,786	40,470	138,468	77,247	63,747
Consolidated net income									138,468us-gaap_ProfitLoss	125,905us-gaap_ProfitLoss	74,459us-gaap_ProfitLoss
Gain (Loss) on Condemnation									1,457us-gaap_GainLossOnCondemnation	0us-gaap_GainLossOnCondemnation	0us-gaap_GainLossOnCondemnation
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax									0	7,133	6,116
Total Assets	3,446,339us-gaap_Assets				3,392,309us-gaap_Assets				3,446,339us-gaap_Assets	3,392,309us-gaap_Assets	3,398,622us-gaap_Assets
Assets of Disposal Group, Including Discontinued Operation											119,852
Capital Improvements									63,721us-gaap_PaymentsForCapitalImprovements	64,714us-gaap_PaymentsForCapitalImprovements	75,260us-gaap_PaymentsForCapitalImprovements
Depreciation on real estate assets and rental homes									111,065	108,229	102,083
Amortization of Intangible Assets for Continuing Operations									(3,999)	(1,940)	(39,467)
Property Operations segment
Segment Reporting Information [Line Items]
Revenue for Reportable Segment									716,942	679,992	648,323
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest									371,875	350,524	336,037
Operations expenses									(345,067)	(329,468)	(312,286)
Operating Income Loss Before Depreciation And Other									371,875	350,524	336,037
Interest income									2,984	3,397	3,075
Income from operations									270,880	250,607	203,999
Reconciliation to Net income available for Common Shares
Total Assets	3,178,883				3,096,826				3,178,883	3,096,826
Capital Improvements									35,973	26,430	30,863
Depreciation on real estate assets and rental homes									99,980	101,374	96,419
Amortization of Intangible Assets for Continuing Operations									(3,999)	(1,940)	(38,694)
Home Sales and Rentals Operations segment
Segment Reporting Information [Line Items]
Revenue for Reportable Segment									44,467	33,281	21,045
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest									7,937	6,426	4,267
Operations expenses									(36,530)	(26,855)	(16,778)
Operating Income Loss Before Depreciation And Other									7,937	6,426	4,267
Interest income									4,466	4,373	4,614
Income from operations									1,318	3,944	2,444
Reconciliation to Net income available for Common Shares
Total Assets	267,456				295,483				267,456	295,483
Capital Improvements									27,748	38,284	44,397
Depreciation on real estate assets and rental homes									11,085	6,855	5,664
Amortization of Intangible Assets for Continuing Operations									0	0	(773)
Maximum
Segment Reporting Information [Line Items]
Number of Reportable Segments									2
Continuing Operations [Member]
Reconciliation to Net income available for Common Shares
Total Assets											3,278,770
Continuing Operations [Member] \| Property Operations segment
Reconciliation to Net income available for Common Shares
Total Assets											2,985,162
Continuing Operations [Member] \| Home Sales and Rentals Operations segment
Reconciliation to Net income available for Common Shares
Total Assets											$ 293,608