VARIABLE INTEREST ENTITIES (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Variable Interest Entity [Line Items]
Trading Securities	$ 71,003		$ 71,003		$ 51,324
Fee revenues from Westwood VIEs	11,700	$ 13,200	36,300	$ 39,100
VIE
Variable Interest Entity [Line Items]
Trading Securities	8,700		8,700		$ 10,700
Common Trust Funds
Variable Interest Entity [Line Items]
Trading Securities	3,000		3,000
UCITS Fund
Variable Interest Entity [Line Items]
Trading Securities	$ 0		$ 0