Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2024
Income Tax Disclosure [Abstract]
Tax Jurisdiction of Domicile [Extensible Enumeration]	US	US	US
Amount
U.S. federal income tax rate	$ 478	$ 643	$ 442
State and local income tax, net of federal income tax effect	62	107	55
Foreign tax effects	0	4	0
Tax credits - research and development	(9)	(14)	(17)
Valuation allowance movement	(1)	10	37
Nondeductible compensation	30	17	18
Tax (windfall) shortfall on share-based payment awards	(26)	(7)	(1)
Other	16	17	16
Changes in unrecognized tax benefits	5	2	5
Other	(4)	(11)	(5)
Provision for income taxes	$ 551	$ 768	$ 550
%
U.S. federal income tax rate	21.00%	21.00%	21.00%
State and local income tax, net of federal income tax effect	3.00%	3.00%	3.00%
Foreign tax effects	0.00%	0.00%	0.00%
Tax credits - research and development	0.00%	0.00%	(1.00%)
Valuation allowance movement	0.00%	0.00%	2.00%
Nondeductible compensation	1.00%	1.00%	1.00%
Tax (windfall) shortfall on share-based payment awards	(1.00%)	0.00%	0.00%
Other	1.00%	0.00%	1.00%
Changes in unrecognized tax benefits	0.00%	0.00%	0.00%
Other	(1.00%)	0.00%	(1.00%)
Effective tax rate	24.00%	25.00%	26.00%