Investments - Summary of Investments in Private Equity Funds (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Investment in Private Equity Funds	$ 54,361	$ 59,508
Private Equity Funds [Member]
Schedule of Equity Method Investments [Line Items]
Investment in Private Equity Funds	15,273	12,095
Glisco II, III and IV [Member] \| Private Equity Funds [Member]
Schedule of Equity Method Investments [Line Items]
Investment in Private Equity Funds	3,504	2,802
Trilantic IV, V and VI [Member] \| Private Equity Funds [Member]
Schedule of Equity Method Investments [Line Items]
Investment in Private Equity Funds	$ 11,769	$ 9,293

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=109237563&loc=d3e33749-111570

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 25
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8813-108599

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant