Condensed Consolidated Statements of Capital - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2020	Jul. 31, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance		$ 1,756,038	$ 1,756,038	$ 1,948,032	$ 1,947,913	$ 1,991,109
Issuance of private perpetual preferred in exchange for common units					0
Conversion of operating partnership units to ESRT Partner's Capital			0	0	0	0
Repurchases of common units (in units)	(477,620)	(656,318)
Repurchases of common units			(7,345)		(121,950)
Equity compensation			5,504	3,647	20,174	15,392
Distributions			(1,050)	(32,180)	(65,369)	(96,370)
Net income (loss)			(12,269)	26,784	(23,599)	55,570
Other comprehensive income (loss)			2,937	(5,937)	(13,354)	(25,355)
Ending balance	$ 1,743,815		$ 1,743,815	$ 1,940,346	$ 1,743,815	$ 1,940,346
General Partner | Series PR Operating Partnership Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)		173,347,000	173,347,000	178,021,000	181,894,000	174,912,000
Beginning balance		$ 1,080,221	$ 1,080,221	$ 1,215,647	$ 1,228,520	$ 1,238,482
Conversion of operating partnership units to ESRT Partner's Capital (in units)			779,000	2,130,000	5,155,000	5,185,000
Conversion of operating partnership units to ESRT Partner's Capital			$ 2,386	$ 12,796	$ 23,903	$ 21,654
Repurchases of common units (in units)			(1,134,000)		(14,205,000)
Repurchases of common units			$ (7,345)		$ (121,950)
Equity compensation (in units)				(1,000)	148,000	53,000
Equity compensation			334	$ 191	$ 719	$ 421
Distributions				(18,907)	(37,181)	(56,098)
Net income (loss)			(8,204)	15,882	(16,502)	32,646
Other comprehensive income (loss)			$ 1,877	$ (3,590)	$ (8,240)	$ (15,086)
Ending balance (in units)	172,992,000		172,992,000	180,150,000	172,992,000	180,150,000
Ending balance	$ 1,069,269		$ 1,069,269	$ 1,222,019	$ 1,069,269	$ 1,222,019
Limited Partners | Series PR Operating Partnership Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)		82,766,000	82,766,000	86,749,000	81,388,000	86,202,000
Beginning balance		$ 647,520	$ 647,520	$ 713,039	$ 680,580	$ 725,108
Issuance of private perpetual preferred in exchange for common units (in units)					(97,000)
Issuance of private perpetual preferred in exchange for common units					$ (800)
Conversion of operating partnership units to ESRT Partner's Capital (in units)			(313,000)	(1,554,000)	(2,986,000)	(2,517,000)
Conversion of operating partnership units to ESRT Partner's Capital			$ (2,435)	$ (12,672)	$ (23,726)	$ (20,655)
Equity compensation (in units)			(1,313,000)	(634,000)	2,835,000	876,000
Equity compensation			$ 5,170	$ 3,456	$ 19,455	$ 14,971
Distributions				(8,880)	(17,619)	(26,884)
Net income (loss)			(3,490)	7,114	(6,954)	14,760
Other comprehensive income (loss)			$ 700	$ (1,578)	$ (3,471)	$ (6,821)
Ending balance (in units)	81,140,000		81,140,000	84,561,000	81,140,000	84,561,000
Ending balance	$ 647,465		$ 647,465	$ 700,479	$ 647,465	$ 700,479
Limited Partners | Series ES Operating Partnership Units Limited Partners
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)		24,529,000	24,529,000	28,518,000	25,810,000	30,129,000
Beginning balance		$ (770)	$ (770)	$ 8,508	$ 7,262	$ 14,399
Issuance of private perpetual preferred in exchange for common units (in units)					43,000
Issuance of private perpetual preferred in exchange for common units					$ 11
Conversion of operating partnership units to ESRT Partner's Capital (in units)			(275,000)	(358,000)	(1,599,000)	(1,969,000)
Conversion of operating partnership units to ESRT Partner's Capital			$ 23	$ (85)	$ (157)	$ (788)
Distributions				(2,960)	(5,264)	(9,020)
Net income (loss)			(1,145)	2,547	(2,327)	5,322
Other comprehensive income (loss)			$ 255	$ (556)	$ (1,162)	$ (2,459)
Ending balance (in units)	24,254,000		24,254,000	28,160,000	24,254,000	28,160,000
Ending balance	$ (1,637)		$ (1,637)	$ 7,454	$ (1,637)	$ 7,454
Limited Partners | Series 60 Operating Partnership Units Limited Partners
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)		6,776,000	6,776,000	7,686,000	7,025,000	8,020,000
Beginning balance		$ (588)	$ (588)	$ 1,871	$ 1,593	$ 3,385
Conversion of operating partnership units to ESRT Partner's Capital (in units)			(136,000)	(142,000)	(385,000)	(476,000)
Conversion of operating partnership units to ESRT Partner's Capital			$ 19	$ (25)	$ (14)	$ (143)
Distributions				(794)	(1,435)	(2,431)
Net income (loss)			(320)	662	(642)	1,427
Other comprehensive income (loss)			$ 70	$ (135)	$ (321)	$ (659)
Ending balance (in units)	6,640,000		6,640,000	7,544,000	6,640,000	7,544,000
Ending balance	$ (819)		$ (819)	$ 1,579	$ (819)	$ 1,579
Limited Partners | Series 250 Operating Partnership Units Limited Partners
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)		3,405,000	3,405,000	3,917,000	3,535,000	4,064,000
Beginning balance		$ (285)	$ (285)	$ 963	$ 807	$ 1,731
Conversion of operating partnership units to ESRT Partner's Capital (in units)			(55,000)	(75,000)	(185,000)	(222,000)
Conversion of operating partnership units to ESRT Partner's Capital			$ 7	$ (14)	$ (6)	$ (68)
Distributions				(405)	(723)	(1,235)
Net income (loss)			(160)	345	(321)	713
Other comprehensive income (loss)			$ 35	$ (78)	$ (160)	$ (330)
Ending balance (in units)	3,350,000		3,350,000	3,842,000	3,350,000	3,842,000
Ending balance	$ (403)		$ (403)	$ 811	$ (403)	$ 811
Private Perpetual Preferred Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)		6,224,000	6,224,000	1,560,000	6,170,000	1,560,000
Beginning balance		$ 29,940	$ 29,940	$ 8,004	$ 29,151	$ 8,004
Issuance of private perpetual preferred in exchange for common units (in units)					54,000
Issuance of private perpetual preferred in exchange for common units					$ 789
Distributions			(1,050)	(234)	(3,147)	(702)
Net income (loss)			$ 1,050	$ 234	$ 3,147	$ 702
Ending balance (in units)	6,224,000		6,224,000	1,560,000	6,224,000	1,560,000
Ending balance	$ 29,940		$ 29,940	$ 8,004	$ 29,940	$ 8,004