Acquisitions Acquisitions - Schedule of pro forma information (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Business Combinations [Abstract]
Total revenues	$ 173,036	$ 82,322	$ 508,507	$ 245,724
Net income attributable to Empire State Realty Trust, Inc.	24,915	(1,082)	59,215	901
Net income attributable to Empire State Realty Trust, Inc.	$ 9,080	$ 0	$ 21,703	$ 0
Net income attributable to Empire State Realty Trust, Inc. per share - basic and diluted	$ 0.09	$ 0.00	$ 0.22	$ 0.00