Debt (Details) $ in Thousands, £ in Millions	1 Months Ended	3 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Jul. 31, 2022 GBP (£)	Jun. 30, 2022 USD ($)	Aug. 02, 2021 GBP (£)
Line of Credit Facility [Line Items]
Proceeds from long-term borrowings		$ 2,000,000	$ 1
Commercial paper	$ 1,300,000	$ 1,300,000			$ 1,400,000
Debt to debt-shareholders' equity ratio		0.62
Maximum
Line of Credit Facility [Line Items]
Debt to debt-shareholders' equity ratio, covenant, maximum		0.65
Medium-Term Note, $300 Million | Medium-term Notes
Line of Credit Facility [Line Items]
Debt matured amount	300,000	$ 300,000
Line of Credit | Bridge Credit Agreement | Bridge Loan
Line of Credit Facility [Line Items]
Aggregate principal amount | £				£ 0		£ 6,500
Line of Credit | Term Loan Facility | Senior Notes
Line of Credit Facility [Line Items]
Proceeds from long-term borrowings	$ 2,000,000
Line of Credit | Term Loan Facility | Senior Notes | Debt Instrument, Periodic Payment, Interest, Period One
Line of Credit Facility [Line Items]
Periodic payment, interest, period	1 month
Line of Credit | Term Loan Facility | Senior Notes | Debt Instrument, Periodic Payment, Interest, Period Two
Line of Credit Facility [Line Items]
Periodic payment, interest, period	3 months
Line of Credit | Term Loan Facility | Senior Notes | Debt Instrument, Periodic Payment, Interest, Period Three
Line of Credit Facility [Line Items]
Periodic payment, interest, period	6 months
Line of Credit | Term Loan Facility | Senior Notes | London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Basis spread on variable rate		1.125%