Shareholders' Equity - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022	Nov. 18, 2024	May 08, 2024	Mar. 31, 2023
Class of Stock [Line Items]
Forward sales equity agreement, settlement in cash	$ 1,380,556
Net proceeds from equity offering	$ 749,987	$ 806,949	$ 776,805
Shelf Registration Statement
Class of Stock [Line Items]
Debt and equity securities, authorized for issuance						$ 5,000,000
Shelf Registration Statement | Subsequent Event
Class of Stock [Line Items]
Debt and equity securities, authorized for issuance value remaining				$ 1,100,000
At-The-Market
Class of Stock [Line Items]
Value of shares authorized for issuance					$ 1,000,000
Forward sales equity agreement, shares (in shares)	13,730,564
Forward sales equity agreement, settlement in cash	$ 1,700,000
Shares issued (in shares)	6,401,469
Net proceeds from equity offering	$ 750,000
Value of shares available for issuance	$ 10,000