SHAREHOLDERS' EQUITY - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended						9 Months Ended
	Jun. 03, 2020	Jun. 01, 2020	Mar. 04, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2020	Jun. 30, 2019	Sep. 30, 2019
Stockholders' Equity Note [Abstract]
Number of common shares authorized to be repurchased (up to) (in shares)				4,000,000,000,000						4,000,000,000,000
Purchases of common shares (in shares)				0			0			1,500,000	0
Purchases of common shares, value										$ 28,500
Cash dividends declared (in dollars per share)	$ 0.25		$ 0.71	$ 0.25	$ 0.71	$ 0.71	$ 0.71	$ 0.71	$ 0.71
Cash dividends paid (in dollars per share)		$ 0.71
Dividends payable				$ 27,244						$ 27,244		$ 77,763