Income Taxes (Details) - USD ($) $ in Millions	1 Months Ended		9 Months Ended
	Jul. 31, 2020	Oct. 31, 2019	Sep. 30, 2020	Dec. 31, 2019	Dec. 31, 2017
Tax Credit Carryforward, Valuation Allowance					$ 3.1
Income tax refund receivable, due to release of valuation allowance against AMT credit carryfowards					$ 3.1
Refund received	$ 1.5	$ 1.6
Amount of federal NOLs applied against taxable capital gains in connection with the conveyance of the school condominium to the SCA			$ 11.6
Taxable capital gains in which federal NOLS were applied against in connection with the conveyance of the school condominium to the SCA			18.5
Federal NOLs utilized to date			28.4
Valuation Allowance			$ 59.7	$ 63.7
Tax Year 2018 to 2020 [Member]
AMT credit carryforwards, percentage eligble for refund pursuant to U.S. Tax Cuts and Jobs Act			50.00%
Tax Year 2021 [Member]
AMT credit carryforwards, percentage eligble for refund pursuant to U.S. Tax Cuts and Jobs Act			100.00%
State and Local Jurisdiction [Member]
Operating Loss Carryforwards			$ 119.9
Federal [Member]
Operating Loss Carryforwards			227.6
New York State [Member]
New York State PNOLC			19.5
New York City [Member]
New York City PNOLC			$ 13.9