Shareholders' Equity - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2024	Jun. 30, 2023
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Shareholders' equity, beginning balance	$ 11,618,639	$ 11,273,209	$ 10,870,064	$ 10,205,205	$ 9,836,274	$ 9,419,091	$ 10,870,064	$ 9,419,091
Other comprehensive income (loss) before reclassifications							(923)	36,881
Amounts reclassified from accumulated other comprehensive income							(7,473)	(1,590)
Total other comprehensive income (loss)	14,432	27,108	(49,936)	43,406	(30,333)	22,218	(8,396)	35,291
Shareholders' equity, ending balance	12,183,076	11,618,639	11,273,209	10,602,381	10,205,205	9,836,274	12,183,076	10,602,381
Available- for-Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Shareholders' equity, beginning balance			(369)			(495)	(369)	(495)
Other comprehensive income (loss) before reclassifications							242	100
Amounts reclassified from accumulated other comprehensive income							0	0
Total other comprehensive income (loss)							242	100
Shareholders' equity, ending balance	(127)			(395)			(127)	(395)
Interest Rate Agreement Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Shareholders' equity, beginning balance			518,897			369,607	518,897	369,607
Other comprehensive income (loss) before reclassifications							(1,165)	36,781
Amounts reclassified from accumulated other comprehensive income							(7,473)	(1,590)
Total other comprehensive income (loss)							(8,638)	35,191
Shareholders' equity, ending balance	510,259			404,798			510,259	404,798
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Shareholders' equity, beginning balance	495,700	468,592	518,528	360,997	391,330	369,112	518,528	369,112
Total other comprehensive income (loss)	14,432	27,108	(49,936)	43,406	(30,333)	22,218
Shareholders' equity, ending balance	$ 510,132	$ 495,700	$ 468,592	$ 404,403	$ 360,997	$ 391,330	$ 510,132	$ 404,403