Investments - Gains and Losses Recognized in Gain (Loss) on Securities, Net (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
(Loss) Gain on Securities [Line Items]
Gain (Loss) on Securities, net	$ 13,828	$ 577	$ (2,012)	$ 2,256
Investments—Consolidated Investment Companies
(Loss) Gain on Securities [Line Items]
Unrealized Gains (Losses)	9,889	424	(464)	1,709
Net Realized Gains (Losses)	(1,108)	(206)	(1,104)	(667)
Gain (Loss) on Securities, net	8,781	218	(1,568)	1,042
Investments—Affiliates and Other
(Loss) Gain on Securities [Line Items]
Unrealized Gains (Losses)	4,991	340	(406)	1,217
Net Realized Gains (Losses)	56	19	(38)	(3)
Gain (Loss) on Securities, net	$ 5,047	$ 359	$ (444)	$ 1,214

The net realized gain (loss) on investments sold during the period, not including gains (losses) on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, which, for cash flow reporting, is a component of proceeds from investing activities.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
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Amount of unrealized and realized gain (loss) on investment in marketable security, including other-than-temporary impairment (OTTI).

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Amount of unrealized gain (loss) on investment in marketable security.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(7)(c))
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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