Furniture, Equipment, and Leasehold Improvements, Net (Schedule of Furniture, equipment and leasehold improvements) (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Leasehold improvements	$ 1,389,000	$ 1,389,000
Equipment	170,000	170,000
Furniture and fixtures	166,000	154,000
Total Furniture, equipment, and leasehold improvements	1,725,000	1,713,000
Less accumulated depreciation	(963,000)	(563,000)
Total Furniture, equipment, and leasehold improvements, net	$ 762,000	$ 1,150,000	[1]

[1] Statement of financial condition as of December 31, 2019 represents the pro forma combination of Siebert and StockCross balances. See "Note 3 - Acquisitions" for additional detail.