Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Commercial real estate properties, at cost:
Land	$ 201,172	$ 187,566
Development costs	6,971	6,459
Building and improvements	1,899,467	1,455,398
Commercial real estate properties, at cost, gross	2,107,610	1,649,423
Less: accumulated depreciation	(354,730)	(295,351)
Commercial real estate properties, net	1,752,880	1,354,072
Cash and cash equivalents	52,918	60,743
Restricted cash	63,821	55,621
Tenant and other receivables, net of allowance of $2,555 and $499 in 2014 and 2013, respectively	29,837	24,817
Deferred rent receivables, net of allowance of $792 and $216 in 2014 and 2013, respectively	94,837	62,689
Prepaid expenses and other assets	31,091	35,407
Deferred costs, net	80,396	78,938
Acquired below-market ground leases, net	392,756	62,312
Acquired lease intangibles, net	312,001	249,983
Goodwill	491,479	491,479
Total assets	3,302,016	2,476,061
Liabilities:
Mortgage notes payable	1,005,569	883,112
Term loan and credit facility	355,600	325,000
Senior unsecured notes	236,999
Accounts payable and accrued expenses	97,413	81,908
Acquired below-market leases, net	148,493	129,882
Deferred revenue and other liabilities	24,728	21,568
Tenants’ security deposits	40,111	31,406
Total liabilities	1,908,913	1,472,876
Empire State Realty Trust, Inc. stockholders' equity:
Preferred stock, $0.01 par value per share, 50,000,000 shares authorized, none issued or outstanding	0	0
Additional paid-in capital	366,215	316,558
Retained earnings	65,568	67,644
Total Empire State Realty Trust, Inc.'s stockholders' equity	432,765	385,158
Private perpetual preferred units, $16.62 per unit liquidation preference, 1,609,813 and 0 issued and outstanding in 2014 and 2013, respectively	8,261
Non-controlling interests in operating partnership	952,077	618,027
Total equity	1,393,103	1,003,185
Total liabilities and equity	3,302,016	2,476,061
Common Class A [Member]
Empire State Realty Trust, Inc. stockholders' equity:
Common stock	970	945
Common Class B [Member]
Empire State Realty Trust, Inc. stockholders' equity:
Common stock	$ 12	$ 11