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Deferred Costs, Acquired Lease Intangibles and Goodwill - Narrative (Details) (USD $)
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
Deferred Costs [Line Items]      
Amortization of deferred leasing costs $ 2,900,000us-gaap_AmortizationOfDeferredLeasingFees $ 2,400,000us-gaap_AmortizationOfDeferredLeasingFees  
Amortization of deferred financing costs 2,400,000us-gaap_AmortizationOfFinancingCosts 1,100,000us-gaap_AmortizationOfFinancingCosts  
Revenue related to amortization of acquired above- and below-market leases, net 5,300,000esrt_RevenueRelatedtoAmortizationofaboveandbelowMarketLeases 1,900,000esrt_RevenueRelatedtoAmortizationofaboveandbelowMarketLeases  
Goodwill 491,479,000us-gaap_Goodwill   491,479,000us-gaap_Goodwill
Empire State Building Observatory Operations [Member]      
Deferred Costs [Line Items]      
Goodwill 227,500,000us-gaap_Goodwill
/ us-gaap_BusinessAcquisitionAxis
= esrt_EmpireStateBuildingObservatoryOperationsMember		    
Empire State Building, L.L.C. [Member]      
Deferred Costs [Line Items]      
Goodwill 264,000,000us-gaap_Goodwill
/ us-gaap_BusinessAcquisitionAxis
= esrt_EmpireStateBuildingL.L.C.Member		    
Lease Agreements [Member]      
Deferred Costs [Line Items]      
Amortization expense related to acquired lease intangibles $ 10,300,000us-gaap_AmortizationOfIntangibleAssets
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_LeaseAgreementsMember		 $ 5,200,000us-gaap_AmortizationOfIntangibleAssets
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_LeaseAgreementsMember