Variable Interest Entities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Variable Interest Entities
Assets Under Management	$ 15,235,000
Corporate Investment	50,324	$ 65,781
Fee revenues from Westwood VIEs	31,000	$ 46,100	$ 51,900
Westwood Funds
Variable Interest Entities
Assets Under Management	2,058,000
Corporate Investment	6,000
Amount at Risk	6,000
Common Trust Funds
Variable Interest Entities
Assets Under Management	1,409,000
Corporate Investment	0
Amount at Risk	0
UCITS Fund
Variable Interest Entities
Assets Under Management	319,000
Corporate Investment	0
Amount at Risk	0
Westwood Hospitality Fund I LLC [Member]
Variable Interest Entities
Assets Under Management	13,000
Corporate Investment	300
Amount at Risk	300
Private Equity Investments [Member]
Variable Interest Entities
Assets Under Management	0
Corporate Investment	12,000
Amount at Risk	12,000
Wealth Management
Variable Interest Entities
Assets Under Management	3,016,000
Institutional
Variable Interest Entities
Assets Under Management	$ 8,420,000