Investments - Schedule of Marketable Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Investment Securities - fair value
Cost	$ 34,560	$ 55,882
Fair Value	40,024	60,990
Sponsored funds
Investment Securities - fair value
Cost	23,735	44,588
Fair Value	27,341	47,654
Equity securities
Investment Securities - fair value
Cost	10,818	11,250
Fair Value	12,679	13,320
Debt securities
Investment Securities - fair value
Cost	7	44
Fair Value	$ 4	$ 16