Investment in Unconsolidated Affiliate (Balance Sheets) (Details) - LSV Asset Management - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Current assets	$ 113,926	$ 144,547
Non-current assets	4,769	5,048
Total assets	118,695	149,595
Current liabilities	42,631	46,828
Non-current liabilities	5,153	5,326
Partners’ capital	70,911	97,441
Total liabilities and partners’ capital	$ 118,695	$ 149,595