Property Acquisitions - 2019 Acquisitions (Details) $ in Millions	1 Months Ended
	May 31, 2019 USD ($)	Dec. 31, 2019 USD ($) ft²
Business Acquisition [Line Items]
Approximate Square Feet | ft²		27,607,971
106 Spring Street
Business Acquisition [Line Items]
Approximate Square Feet | ft²		5,928
Gross Asset Valuation (in millions)		$ 80.2
410 Tenth Avenue
Business Acquisition [Line Items]
Approximate Square Feet | ft²		638,000
Gross Asset Valuation (in millions)		$ 440.0
Interest acquired	70.87%
Fair value adjustment	$ 67.6
net intangible lease liabilities recognized	$ 18.3
110 Greene Street
Business Acquisition [Line Items]
Approximate Square Feet | ft²		223,600
Gross Asset Valuation (in millions)		$ 256.5
Interest acquired	10.00%