Brokerage And Custodial Fees (Tables)

6 Months Ended

12 Months Ended

Jun. 30, 2017

Dec. 31, 2016

Brokerage And Custodial Fees [Abstract]

Schedule Of Brokerage And Custodial Fees

	Three months ending June 30,		Six months ending June 30,
	2017	2016	2017	2016
Brokerage fees	$             3,158,867	$             3,211,829	$             6,409,193	$             6,512,152
Custodial fees	7	6	13	33
Total	$             3,158,874	$             3,211,835	$             6,409,206	$             6,512,185

	2016	2015	2014
Brokerage fees	$           13,188,941	$           13,566,607	$           15,803,101
Custodial fees	46	131	213
Total	$           13,188,987	$           13,566,738	$           15,803,314

Schedule Of Brokerage Fee Rebates

	Three months ending June 30,		Six months ending June 30,
	2017	2016	2017	2016
Brokerage fee rebates	$                195,331	$                193,450	$                387,151	$                387,116