SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2025	Mar. 31, 2024	Sep. 30, 2024	Jun. 30, 2024
Accounting Policies [Abstract]
Effective rate for income taxes (as a percent)	34.00%	31.10%	0.30%	33.90%
Basis-point change from the prior-year period (as a percent)	2.90%		(33.60%)
Transition tax accrual adjustment	$ 73		$ 73		$ 73
Transition tax, unrecognized tax benefits	73		73		$ 73
Gross unrecognized tax benefits	139		139			$ 65
Total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate	129		129
Gross interest and penalty accrued	1		4
Total gross accrued interest and penalties related to unrecognized tax benefits	21		21			17
Other assets	1,726		1,726			1,460
Deferred tax assets	$ 1,298		$ 1,298			$ 1,018