INCOME TAXES - UNRECOGNIZED TAX BENEFITS ROLLFORWARD (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross unrecognized tax benefits at the beginning of the year	$ 0	$ 0	$ 0
Additions from tax positions taken in the current year	140	0	0
Additions from tax positions taken in prior years	1,041	0	0
Reductions from tax positions taken in prior years	0	0	0
Tax settlements	0	0	0
Gross unrecognized tax benefits at end of the year	1,181	$ 0	$ 0
Unrecognized tax benefits that will impact the company's effective tax rate	$ 1,200