Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Empire State Realty Trust, Inc. stockholders' equity:
Preferred stock, par value (USD per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	50,000,000	50,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Class A Common Stock
Empire State Realty Trust, Inc. stockholders' equity:
Common stock, par value (USD per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	170,555,274	180,877,597
Common stock, shares outstanding (in shares)	170,555,274	180,877,597
Class B Common Stock
Empire State Realty Trust, Inc. stockholders' equity:
Common stock, par value (USD per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock, shares issued (in shares)	1,010,130	1,016,799
Common stock, shares outstanding (in shares)	1,010,130	1,016,799
Private Perpetual Preferred Units, Series 2019
Empire State Realty Trust, Inc. stockholders' equity:
Private perpetual preferred units, liquidation preference per share (in USD per share)	$ 13.52	$ 13.52
Private perpetual preferred units, issued, shares	4,664,038	4,610,383
Private perpetual preferred units, outstanding, shares	4,664,038	4,610,383
Private Perpetual Preferred Units, Series 2014
Empire State Realty Trust, Inc. stockholders' equity:
Private perpetual preferred units, liquidation preference per share (in USD per share)	$ 16.62	$ 16.62
Private perpetual preferred units, issued, shares	1,560,360	1,560,360
Private perpetual preferred units, outstanding, shares	1,560,360	1,560,360