BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Advertising Costs and Expenses & Severance Costs and Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Schedule of Accrued Severance Liability By Segment [Line Items]
Advertising costs and expenses	$ 27,300	$ 27,000	$ 26,700
Prepaid advertising	$ 222	$ 432