EQUITY SECURITIES PORTFOLIO INVESTMENT - Unrealized and Realized Gains or Losses on Investment (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Debt and Equity Securities, FV-NI [Line Items]
Change in fair value of investment			$ 18,783	$ (266,202)
Trading Securites - LF Fund Public Securities
Debt and Equity Securities, FV-NI [Line Items]
Change in fair value of investment	$ 8,187	$ (39,008)	7,677	(243,106)
Realized investment gains (losses)	0	36,397	0	101,102
Trading Securites Lf Fund Securities
Debt and Equity Securities, FV-NI [Line Items]
Net realized and unrealized gain (loss) on investments	$ 8,187	$ (2,611)	$ 7,677	$ (142,004)

Amount of unrealized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(3)(d)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 321
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479536/321-10-50-4

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Amount of realized and unrealized gain (loss) on investment.

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Reference 1: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-28

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7(c),9(a))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

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