PROPERTY AND EQUIPMENT, NET (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, at cost	$ 2,906,648	$ 2,843,690
Less: accumulated depreciation	(1,408,601)	(1,323,003)
Property and equipment, net	1,498,047	1,520,687
Finance lease, right-of-use asset	29,100	29,400
Depreciation expense	107,600	121,800	$ 81,300
Accelerated depreciation		21,600
Restatement Adjustment
Property, Plant and Equipment, Net, by Type [Abstract]
Depreciation and amortization expense		6,300
Land
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, at cost	44,848	44,848
Land improvements
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, at cost	101,746	100,879
Buildings and improvements
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, at cost	1,852,131	1,839,872
Build-to-suit asset
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, at cost	0	93,828
Furniture and equipment
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, at cost	655,529	660,936
Construction in process
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, at cost	252,394	103,327
Project Inspire | Construction in process
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, at cost	$ 230,400	$ 99,300