Income Taxes - Effective tax rate (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Taxes
Tax (benefit) at statutory rate	$ 1,500	$ (141,000)
State and local taxes, net of federal benefit	500	(69,000)
Permanent differences	0	0
Change in valuation allowance	(2,000)	210,000
Tax due	$ 0	$ 0