Equity - Shares and Units (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2021 USD ($) shares	Jun. 30, 2021 USD ($) shares	May 16, 2019 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
OP Unit, redemption term for cash (in years)		1 year
OP Unit, exchange ratio to common stock	1	1
Dividends on common stock received until performance criteria met for LTIP units (as a percent)	10.00%	10.00%
Dividends on common stock received after performance criteria met for LTIP units (as a percent)	90.00%	90.00%
Dividends on common stock received in periods after performance criteria met for LTIP units (as a percent)	100.00%	100.00%
OP units outstanding (in shares)	285,722,956	285,722,956
Stock repurchase authorized amount | $	$ 500,000,000	$ 500,000,000
Purchases of equity securities (shares)	0
Empire state realty trust
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
OP units owned by the Company (in shares)	173,400,552	173,400,552
Other partners, certain directors, officers and other members of executive management
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
OP units not owned by the Company (in shares)	112,322,404	112,322,404
Empire state realty OP | Empire state realty trust
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
OP units owned by the Company (as a percent)		60.70%
Empire state realty OP | Other partners, certain directors, officers and other members of executive management
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
OP units not owned by the Company (as a percent)		39.30%
2019 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized under the plan (in shares)	11,000,000.0	11,000,000.0	11,000,000.0