Revenue Recognition (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Stock borrow / stock loan	$ 4,183,000	$ 3,465,000	$ 11,909,000	$ 7,552,000
Gross revenue from stock borrow/ Stock loan	9,921,000	7,754,000	26,222,000	19,605,000
Expenses from stock borrow/stock loan	$ 5,738,000	$ 4,289,000	$ 14,313,000	$ 12,053,000