Investments - Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Investment Holdings [Line Items]
Long-term incentive compensation-related	$ 50,902	$ 52,429
Investments owned	266,794	714,344
Seed capital
Investment Holdings [Line Items]
Investments owned	$ 358,100	$ 391,600

Value of the investment at close of period. For schedules of investments that are categorized, the value would be aggregated by category. For investment in and advances to affiliates, if operations of any controlled companies are different in character from those of the company, group such affiliates within divisions and by type of activities.

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Balance Type:	debit
Period Type:	instant