Borrowing Arrangements - Fair Value of Market Price (Details) - Senior Notes - USD ($)	Apr. 30, 2023	Oct. 31, 2021	Jan. 31, 2020	Jun. 30, 2015
2015 Notes
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 300,000,000			$ 300,000,000
Fair value	298,000,000
2017 Notes
Debt Instrument [Line Items]
Aggregate Principal Amount	500,000,000
Fair value	485,000,000
2020 Notes
Debt Instrument [Line Items]
Aggregate Principal Amount	500,000,000		$ 500,000,000
Fair value	447,000,000
2021 Notes
Debt Instrument [Line Items]
Aggregate Principal Amount	1,000,000,000	$ 1,000,000,000
Fair value	$ 834,000,000