SHAREHOLDERS' EQUITY - Share Buyback (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended	13 Months Ended	19 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 12, 2017	Mar. 11, 2016
Treasury Stock, Number of Shares and Restriction Disclosures [Abstract]
Treasury stock acquired, average cost per share (in dollars per share)		$ 11.73
Treasury stock, value acquired, cost method	$ 20,411	$ 41
New share repurchase program
Treasury Stock, Number of Shares and Restriction Disclosures [Abstract]
Authorized amount under the share repurchase program				$ 5,000	$ 5,000
Treasury stock, shares acquired (in shares)		3,500	98,318
Treasury stock acquired, average cost per share (in dollars per share)			$ 7.37
Treasury stock, value acquired, cost method			$ 724