Furniture, Equipment and Leasehold Improvements, Net - Schedule of Furniture, Equipment and Leasehold Improvements (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Furniture, equipment and leasehold improvements [Abstract]
Furniture, equipment and leasehold improvements, gross	$ 494,546	$ 929,549
Less: Accumulated depreciation and amortization	(318,198)	(740,291)
Furniture, equipment and leasehold improvements, net	176,348	189,258
Gain (loss) on disposition of property plant equipment	461,700
Furniture and equipment (1)
Furniture, equipment and leasehold improvements [Abstract]
Furniture, equipment and leasehold improvements, gross	168,415	605,567
Leasehold improvements (1)
Furniture, equipment and leasehold improvements [Abstract]
Furniture, equipment and leasehold improvements, gross	$ 326,131	$ 323,982