COMMON STOCK EQUITY - NARRATIVE (Details) - USD ($) $ / shares in Units, $ in Thousands		6 Months Ended
	Dec. 04, 2019	Mar. 31, 2020	Mar. 31, 2019
Class of Stock [Line Items]
Number of shares issued in transaction (in shares)	6,545,454
Proceeds from issuance of common stock - public equity offering	$ 212,900	$ 212,900	$ 0
Directly Issued Common Stock
Class of Stock [Line Items]
Number of shares issued in transaction (in shares)	5,333,334
Forward Sales Agreements
Class of Stock [Line Items]
Number of shares issued in transaction (in shares)	1,212,120
Conversion price per share (in dollars per share)	$ 40.0125
Forward sales agreement, settlement, amount		$ 10,000
Forward sales agreement, settlement (in shares)		305,727