Shareholders' Equity - Schedule of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Shareholders' equity, beginning balance	$ 10,205,205	$ 8,983,231	$ 9,419,091	$ 7,906,889
Other comprehensive income (loss) before reclassifications			36,881	233,175
Amounts reclassified from accumulated other comprehensive income			(1,590)	2,232
Net current-period other comprehensive income (loss)	43,406	159,631	35,291	235,407
Shareholders' equity, ending balance	10,602,381	9,268,171	10,602,381	9,268,171
Available- for-Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Shareholders' equity, beginning balance			(495)	47
Other comprehensive income (loss) before reclassifications			100	(336)
Amounts reclassified from accumulated other comprehensive income			0	0
Net current-period other comprehensive income (loss)			100	(336)
Shareholders' equity, ending balance	(395)	(289)	(395)	(289)
Interest Rate Agreement Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Shareholders' equity, beginning balance			369,607	69,756
Other comprehensive income (loss) before reclassifications			36,781	233,511
Amounts reclassified from accumulated other comprehensive income			(1,590)	2,232
Net current-period other comprehensive income (loss)			35,191	235,743
Shareholders' equity, ending balance	404,798	305,499	404,798	305,499
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Shareholders' equity, beginning balance	360,997	145,579	369,112	69,803
Shareholders' equity, ending balance	$ 404,403	$ 305,210	$ 404,403	$ 305,210