Property Acquisitions (Details) $ in Millions	1 Months Ended
	Jan. 31, 2020 USD ($) ft²	Sep. 30, 2020 ft²
Property Acquisitions
Approximate Square Feet		30,328,709
762 Madison Avenue
Property Acquisitions
Approximate Square Feet	6,109
Gross Asset Valuation (in millions) | $	$ 29.3
Interest acquired	10.00%
707 Eleventh Avenue
Property Acquisitions
Approximate Square Feet	159,720
Gross Asset Valuation (in millions) | $	$ 90.0
126-132 Nassau Street
Property Acquisitions
Approximate Square Feet	98,412
Gross Asset Valuation (in millions) | $	$ 0.0
Ground leases, term of contract	99 years