Receivables From, Payables To, and Deposits With Broker-Dealers and Clearing Organizations (Schedule of Receivable) (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Receivables from and deposits with broker-dealers and clearing organizations
DTCC / OCC / NSCC	$ 10,968,000	$ 17,841,000
Goldman Sachs	335,000	2,430,000
Pershing Capital	1,193,000	1,266,000
NFS	974,000	1,061,000
Securities fail-to-deliver	174,000	379,000
Globalshares	55,000	46,000
Other receivables	27,000
Total Receivables from and deposits with broker-dealers and clearing organizations	13,726,000	23,023,000
Payables to broker-dealers and clearing organizations
Securities fail-to-receive	254,000	1,810,000
Total Payables to broker-dealers and clearing organizations	$ 254,000	$ 1,810,000