Referral Fees (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Referral Fees
Referral fees	$ 738,000	$ 86,000	[1]

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