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Debt - Senior Notes (Details) - USD ($)	Jun. 30, 2025	May 13, 2025	Sep. 30, 2024	Dec. 17, 2021	Dec. 06, 2019	May 08, 2018
Senior Notes
Debt Instrument [Line Items]
Face Value	$ 2,800,000,000		$ 1,300,000,000
Fair Value	2,785,125,000		1,263,500,000
The 2018 Senior Notes \| Senior Notes
Debt Instrument [Line Items]
Senior Notes issued in a private placement to a group of institutional investors						$ 400,000,000
Debt instrument, stated percentage						5.25%
Face Value	400,000,000		400,000,000
Fair Value	399,000,000		399,500,000
Senior Notes December 2019 \| Senior Notes
Debt Instrument [Line Items]
Senior Notes issued in a private placement to a group of institutional investors					$ 350,000,000
Debt instrument, stated percentage					4.00%
Senior Notes December 2021 \| Senior Notes
Debt Instrument [Line Items]
Senior Notes issued in a private placement to a group of institutional investors				$ 550,000,000
Debt instrument, stated percentage				4.00%
The 2025 Senior Notes \| Senior Notes
Debt Instrument [Line Items]
Senior Notes issued in a private placement to a group of institutional investors		$ 1,500,000,000
Debt instrument, stated percentage		6.00%
Face Value	1,500,000,000		0
Fair Value	1,513,125,000		0
The $300 Million Term Loan \| Revolving line of credit \| Unsecured Debt
Debt Instrument [Line Items]
Senior Notes issued in a private placement to a group of institutional investors		$ 300,000,000
The $450 Million Term Loan \| Revolving line of credit \| Unsecured Debt
Debt Instrument [Line Items]
Senior Notes issued in a private placement to a group of institutional investors		$ 450,000,000
The 2019 Senior Notes and the 2021 Senior Notes \| Senior Notes
Debt Instrument [Line Items]
Face Value	900,000,000		900,000,000
Fair Value	$ 873,000,000		$ 864,000,000