Debt (Credit Facilities) (Details)	3 Months Ended
	Mar. 31, 2025 USD ($) borrowing	Sep. 30, 2024 USD ($)
Debt Instrument [Line Items]
Number of instruments unrecognized | borrowing	2
Bonds
Debt Instrument [Line Items]
Long-term debt, principal amount	$ 1,081,800,000
Saudi Riyal Loan Facility Variable Rate Seven Point Three Five Percent | Bonds
Debt Instrument [Line Items]
Interest rate, variable percentage		7.35%
Long-term debt, principal amount		$ 451,100,000
Saudi Riyal Loan Facility Variable Rate Two Point Zero Percent | Bonds
Debt Instrument [Line Items]
Interest rate, stated percentage		2.00%
Long-term debt, principal amount		$ 222,200,000
Revolving credit agreement | 364-Day Agreement | Line of Credit
Debt Instrument [Line Items]
Debt instrument term	364 days
Maximum borrowing capacity	$ 500,000,000
Credit facility, amount borrowed and outstanding	$ 0
Revolving credit agreement | Credit Agreement 2024 | Line of Credit
Debt Instrument [Line Items]
Debt instrument term	5 years
Maximum borrowing capacity	$ 3,000,000,000
Credit facility, amount borrowed and outstanding	0
Foreign credit facilities | Credit facilities of foreign subsidiaries
Debt Instrument [Line Items]
Maximum borrowing capacity	415,700,000	1,223,900,000
Credit facility, amount borrowed and outstanding	$ 415,700,000	$ 1,129,000,000