SHAREHOLDERS' EQUITY - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Sep. 09, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Stockholders' Equity Note [Abstract]
Number of common shares authorized to be repurchased (in shares)		4,000,000,000,000
Shares of common stock repurchased (in shares)		1,500,000	1,000,000.0	0
Aggregate cost of repurchased shares		$ 28,500	$ 42,800
Cash dividends		$ (209,798)	$ (313,088)	$ (310,024)
Dividends declared (in dollars per share)	$ 0.25	$ 1.92	$ 2.84	$ 2.82
Dividends payable		$ 27,226	$ 77,763