COLLATERALIZED ARRANGEMENTS AND FINANCING - Summary of Prime Financing Lending Arrangements (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss [Abstract]
Fiat and payment stablecoin loan receivables	$ 1,958,539	$ 1,340,213
Crypto asset loan receivables	17,598	14,479
Total loan receivables	$ 1,976,137	$ 1,354,692

Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable classified as current. Excludes net investment in lease.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 948
-SubTopic 310
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477011/948-310-45-1

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