CLEARING OPERATIONS - Valuation (Details) $ / shares in Units, $ in Millions	Sep. 30, 2022 USD ($) item $ / shares	Jun. 30, 2022 USD ($)
Fair Value - Digital Assets - Safeguarded Assets and Safeguarded Liabilities
Fair Value	$ 24.0	$ 22.4
Bitcoin
Fair Value - Digital Assets - Safeguarded Assets and Safeguarded Liabilities
Number of Units | item	709
Valuation | $ / shares	$ 19,427
Fair Value	$ 13.8
Ethereum
Fair Value - Digital Assets - Safeguarded Assets and Safeguarded Liabilities
Number of Units | item	5,735
Valuation | $ / shares	$ 1,332
Fair Value	$ 7.6
Litecoin
Fair Value - Digital Assets - Safeguarded Assets and Safeguarded Liabilities
Number of Units | item	14,581
Valuation | $ / shares	$ 53
Fair Value	$ 0.8
Bitcoin Cash
Fair Value - Digital Assets - Safeguarded Assets and Safeguarded Liabilities
Number of Units | item	6,033
Valuation | $ / shares	$ 122
Fair Value	$ 0.7
USD Coin
Fair Value - Digital Assets - Safeguarded Assets and Safeguarded Liabilities
Number of Units | item	1,098,450
Valuation | $ / shares	$ 1
Fair Value	$ 1.1