Commitments and Contingencies (Details)	1 Months Ended	3 Months Ended
	Feb. 28, 2021 property	Mar. 31, 2021 USD ($)
Property Subject to or Available for Operating Lease [Line Items]
Debt, net		$ 1,843,593,000
Winter Storm
Property Subject to or Available for Operating Lease [Line Items]
Number of properties damaged | property	1
Write-off of fixed assets		1,200,000
Restoration liability		6,400,000
Insurance proceeds		4,000,000.0
Insurance receivable		3,600,000
One and Two Commerce Square | Preferred Equity Investment
Property Subject to or Available for Operating Lease [Line Items]
Other commitments		20,000,000.0
Amount committed to date		2,100,000
Drexel Square
Property Subject to or Available for Operating Lease [Line Items]
Other commitments		7,600,000
Estimated potential additional contribution obligation		2,500,000
4040 Wilson Venture
Property Subject to or Available for Operating Lease [Line Items]
Debt, net		150,000,000.0
Guarantees, maximum exposure amount		41,300,000
Unconsolidated Real Estate Ventures
Property Subject to or Available for Operating Lease [Line Items]
Real estate ventures aggregate indebtedness		$ 961,900,000