Software, Net (Schedule of Software, Net) (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Total Software	$ 2,933,000	$ 2,534,000
Total Software, net	1,334,000	1,888,000	[1]
Robo-Advisor [Member]
Finite-Lived Intangible Assets [Line Items]
Total Software	763,000	763,000
Less accumulated amortization	(509,000)	(254,000)
Other purchased software [Member]
Finite-Lived Intangible Assets [Line Items]
Total Software	2,170,000	1,771,000
Less accumulated amortization	$ (1,090,000)	$ (392,000)

[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.