BROKER DEALERS (Details)	9 Months Ended
	Sep. 30, 2017 USD ($) subsidiary	Jun. 30, 2016 subsidiary
Related Party Transaction [Line Items]
Number of broker-dealer subsidiaries (in subsidiary) | subsidiary	2	2
SpeedRoute
Related Party Transaction [Line Items]
Actual net capital	$ 496,480
Amount in excess of required net capital	391,483
Minimum required net capital	$ 104,997
Net capital ratio (as a percent)	3.17
Pro Securities
Related Party Transaction [Line Items]
Actual net capital	$ 9,194
Amount in excess of required net capital	4,194
Minimum required net capital	$ 5,000
Net capital ratio (as a percent)	2.34