Debt - Additional Information (Details) ft² in Millions		1 Months Ended	12 Months Ended
	Nov. 25, 2019 USD ($) ft²	Nov. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) ft²	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Debt Instrument [Line Items]
Proceeds from debt refinancing			$ 1,259,843,000	$ 16,700,000	$ 991,556,000
Area of office and retail properties | ft²			13.1
Repayments of notes and mortgages payable			$ 1,050,000,000		$ 1,044,821,000
1633 Broadway [Member]
Debt Instrument [Line Items]
Proceeds from debt refinancing		$ 1,250,000,000	$ 1,250,000,000
Debt instrument fixed interest rate		2.99%
Fixed Rate of 2.99% [Member] | 1633 Broadway [Member]
Debt Instrument [Line Items]
Proceeds from debt refinancing	$ 1,250,000,000
Area of office and retail properties | ft²	2.5
Tenure of long term debt	10 years
Debt instrument fixed interest rate	2.99%
Maturity date of debt	2029-12
Repayments of notes and mortgages payable	$ 1,050,000,000.00
Notes and mortgages payable, Interest Rate	3.55%
Maturity date of debt	2022-12
Remaining proceeds after repayment of existing loan	$ 179,000,000