Dispositions - Additional Information (Details)	6 Months Ended
	Jun. 30, 2020 USD ($) ft²	May 27, 2020 USD ($) ft² $ / ft²	Mar. 06, 2020 USD ($) ft²	Dec. 31, 2019 USD ($)
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Area of office and retail properties | ft²	13,100,000
Notes and mortgages payable	$ 3,812,716,000			$ 3,809,643,000
1633 Broadway [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Sale percentage of office and retail properties		10.00%
Area of office and retail properties | ft²		2,500,000
Valuation of office and retail properties		$ 2,400,000,000
Cost per square foot | $ / ft²		960
Notes and mortgages payable		$ 1,250,000,000
Sale agreement amount		$ 111,984,000
Minority interest in jount ventures decrease, percentage	10.00%
1899 Pennsylvania Avenue [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Area of office and retail properties | ft²			191,000
Sale agreement amount			$ 115,000,000